• Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
    Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.

WARNING: SATA Cautions

I

Ice Czar

Guest
I have for many months now been passing out the information that SATA is a more reliable form of data transfer than Parallel ATA
and the following has been called to my attention (by CityK), that while theoretically that is true, in implementation it may not be,
if fact it could be worse


SATA Implementation Cautions @ ATA-ATAPI.com
If you are setting up a system using SATA here are some things you must be aware of:

* DO NOT operate SATA devices outside of a sealed system unit. DO NOT operate SATA devices from a power supply that is not the system unit's power supply.
* DO NOT tie wrap SATA cables together. DO NOT put sharp bends in SATA cables. DO NOT route SATA cables near PATA cables. Avoid placing SATA devices close to each other such that the SATA cable connectors are close to each other.
* DO NOT operate a radio transmitter (such as a cell phone) near an exposed SATA cable or device.

Why all these warning? The basic problem is the SATA cable connector is not shielded. This has to be the number one most stupid thing that has been done in the SATA world.
Click to expand...


Regarding the theoretical benefits (and real PATA issues)
SATA and the 7 Deadly Sins of Parallel ATA
ATA Not So Frequently Asked Questions

as of right now, Im unaware of any shielded SATA cables
youd have to shield them yourself, I'll post some info on that later.

Id read that top article and follow those instructions carefully
in addition Hale offers a Demo version of ATACT to check the data integrity, and a soon as I can figue out how to actually run it :p
I'll post a tutorial

PS anyone know how to read a .UG file?
 
Ice, .ug = Unigrafix file? You probably need AutoCad or a Unigrafix package to open it.
 
Integrity Testing

USING ATACT (edited into the top, follies follow :p )

well this is how I did it, and it was only employed on my PATA onboard channels
so for IDE Cards or RAID Channels, SATA ports, youll have to blunder around yourself :p

download ATACT demo
extract and change the .ug files to .txt files and read them
Download Dr DOS
run it and it will extract to a new floopy
access the floppy and remove the CONFIG.SYS file
(if you employ an MS-DOS boot disk you also need to remove the AUTOEXEC.BAT)
then add the ATACT.EXE file to it

reboot and change your boot order to floopy first if it isnt already
I was prompted to enter the Date and Time (???)
and then given an A:/ prompt
I always check the directory at that point (just to be sure)
A:/DIR which looked OK so
A:/ATACT P0 = runs on Primary Channel Device Zero (Master)
A:/ATACT P1 = runs on Primary Channel Device One (Slave)
A:/ATACT P01 = runs on Primary Channel Both Devices
A:/ATACT S0 = runs on Secondary Channel Device Zero (Master)
A:/ATACT S1 = runs on Secondary Channel Device One (Slave)
A:/ATACT S01 = runs on Secondary Channel Both Devices

there are lots of other switches, troubleshooting and modes
but I havent tried them, so Good Luck

another way to test data integrity is to copy and transfer it between partitions, drives, arrays, and computers, then run a checksum on the both sets of files to compare them, they should match
a very good freeware checksum is Fsum by slavasoft
Possibility to calculate a file message digest and/or a checksum using any of the 12 well-known and documented hash and checksum algorithms: MD2, MD4, MD5, SHA-1, SHA-2( 256, 384, 512), RIPEMD-160, PANAMA, TIGER, ADLER32, CRC32;
Click to expand...

however since IDE covers up errors and resends them, while this will reveal if the data has been transfered without error, it wont verify that the data signaling is optimized, actual errors are pretty rare, so even a few are a sign something is wrong, in my personal experience various compressed archives seem to be more suceptible to corruption than a normal file, data corruption can strike any backup or redundancy strategy, so its important to test, and on occassion retest, when you need to restore important data isnt the time to find out its corrupted ;)

Good Luck, and have fun.
 
DUH :rolleyes:
I should have tried that first :p

the funny thing was there are 2 TXT files already
 
if anyone comes across shielded SATA cables for sale plz do post in here.

You can put the URL in a *.ug file so everyone but Czar can see if you like.. :D
 
Originally posted by SKiTLz
You can put the URL in a *.ug file so everyone but Czar can see if you like.. :D
Click to expand...

you are so cruel

youve made me cry :p

threads are multipling like rabbits
Shielding SATA cables
with cool pics of Voodooo's DIY shielding

RAID Issues


regarding MrMike's links, and theTIK's question of how concerned
(1st link)

both the
http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=316603
and the
http://www.thermaltake.com/accessories/roundCables/RoundCable.htm
are supposedly shielded
the thermaltake says its PVC
now thats the same stuff almost every mobo ATA cable is made out of
and its the cheap way to go
look at these tests (click on Pics for animated gif)


but to answer your question
if it was me
if it was for a desktop rig, that wasnt for business, your fine
on the other hand if your flying a workstation or operating a database server
Id be concerned

but the same could be said about any PATA interface (see below), and keep in mind even with these issues, its still more likely your memory is the probable cause of corruption

unless your actually experiencing problem or are practicing due diligence in an enterprise environment I wouldnt sweat it immediately (but I would consider it a better investment than a light kit or window :p)

ATA Not so Frequently Asked Questions
Or: Why Ribbon Cables are unsuitable
for RF transmission of data

The following article was written by snn47 to address some of the issues associated with standard ribbon cables and the use of e.g. removable drive racks as an attempt to share some insight into factors that can adversely affect the life or reliability of of desktop Hard Disk Drives. Specifically, issues like why some drives are working in some systems and not in others, the impact of cable routing and why is it that the drive manufacturers always recommend using their own cables (if supplied with the drive).

There is a ton of data in this article, some of which are of interest only for the EE-crowd or else some nerds but there is also some stuff of why sometimes simply rerouting the cable can solve the problems at hand.



Some IDE-HDDs run stable in one system even when overclocked, in another system the same drives won't work (stable) even when run within specs. There are several factors that fall in to the general picture of HDD failure and which may or may not relate to each other. Therefore, we need to make sure that all parameters are taken into account and weighed against each other.
In detail, those parameters are:


the actual problem (e.g. data corruption vs. physical failure of the drive)
under which circumstances, that is, setup and settings they occurred (e.g. system-type,
clock speed)
cable length and type (e.g. rounded, twisted pair etc.)
number of connectors (master, slave)
use of a drive bay or not

More >
Click to expand...

when you look at say and external RAID array, every single bridge
PCI slot > Host Bus Adapter > Cable > External Array's Internal Bus > RAID Card > Internal Bus > Hot Swap Sled
has been tested by a EE, for signal quality (and as far as I know, even when its an IDE RAID, the first stretch to the External Arrays Bus is always SCSI)

your mobo\drives\PSU also puts out Electromagnetic Fields which
can interfere with signal quality in an unsheilded cable, which is where routing ccomes into it, as EMFields obey the Inverse Square Law
an additional routing consideration
6. If the cable is run above metal the electronic properties change we'll have another jump/change in impedance

with all this youd think there would be more problems and often they go un-noticed
Fancy IDE leads - The Terrible Truth
How come they work, then?

What may be causing you a certain amount of confusion at this juncture is the fact that there are people all over the world successfully using over-length ATA cables. Including round ones. Some people use cables 750mm or even 900mm in length, without causing any obvious explosions or outbreaks of smallpox. How so, I hear you ask.

Again, two reasons.

Reason one - good enough components at each end of the cable can deal with more signal corruption than the IDE specification demands of them. Modern ATA hardware is pretty darn good at dealing with lousy cables. Older drives typically have lower tolerances, and some older motherboard IDE chipsets did brilliant things like effectively connect the two IDE connectors together as far as length-related problems went, resulting in seven inch real world cable length limits if you attached cables to both connectors. But those days are largely past. Current consumer IDE hardware can shout through the noise quite well.

Reason two - IDE covers up data loss problems. The ATA interface has CRC error checking built in. When data's munged in transit down the cable, the error is detected and the data is resent.
Click to expand...
Click to expand...
 
This is more like a Chicken Little post. I've got both of my SATA Cables run close together in my case. They also make a pretty sharp bend off the connector because I have my drives flipped around. Haven't had a single problem with crashes, or lockups, or data corruption or loss. My map load times in BF42 are non-existant. my boot up time is phenomenal (would be better if I didn't have the PATA PCI Card installed). You guys are right however that I wouldn't use it in an enterprise environment. But for consumer level use it's perfectly fine.
 
Originally posted by Mr_Evil
You guys are right however that I wouldn't use it in an enterprise environment. But for consumer level use it's perfectly fine.
Click to expand...

the same could be said of PATA @ 100 or 133MB/s

SATA and the 7 Deadly Sins of Parallel ATA
ATA Not So Frequently Asked Questions

unless of course you are actively having problems

from the 2nd link:
The following article was written by snn47 to address some of the issues associated with standard ribbon cables and the use of e.g. removable drive racks as an attempt to share some insight into factors that can adversely affect the life or reliability of of desktop Hard Disk Drives. Specifically, issues like why some drives are working in some systems and not in others, the impact of cable routing and why is it that the drive manufacturers always recommend using their own cables (if supplied with the drive).

There is a ton of data in this article, some of which are of interest only for the EE-crowd or else some nerds but there is also some stuff of why sometimes simply rerouting the cable can solve the problems at hand.
Click to expand...

to wit, my SX6000 RAID 5 error log when it was running the drives via IDE hotswap bays (now they are directly connected)

11/29/03 08:06:57 Warning Read/Write Error Drive WDC WD400BB-00CFC0 (0x00000002 ch 3) of Array Array1 (0x00000018) has Read Write Error ch3 LBA=1305d9b cmd=20 Disk Status= 51.
11/27/03 08:35:49 Warning Read/Write Error Drive WDC WD400BB-00CFC0 (0x00000002 ch 3) of Array Array1 (0x00000018) has Read Write Error ch3 LBA=4537600 cmd=20 Disk Status= 51.
11/26/03 09:11:21 Warning Read/Write Error Drive WDC WD400BB-00CFC0 (0x00000002 ch 3) of Array Array1 (0x00000018) has Read Write Error ch3 LBA=4536773 cmd=20 Disk Status= 51.
11/18/03 17:17:28 Warning Read/Write Error Drive WDC WD400BB-00CFC0 (0x00000002 ch 3) of Array Array1 (0x00000018) has Read Write Error ch3 LBA=4537e00 cmd=20 Disk Status= 51.
11/06/03 19:29:49 Warning Read/Write Error Drive WDC WD400BB-00CFC0 (0x00000002 ch 3) of Array Array1 (0x00000018) has Read Write Error ch3 LBA=4537180 cmd=20 Disk Status= 51.
11/06/03 17:13:35 Warning Read/Write Error Drive WDC WD400BB-00CFC0 (0x00000002 ch 3) of Array Array1 (0x00000018) has Read Write Error ch3 LBA=4537c80 cmd=20 Disk Status= 51.
11/05/03 20:16:51 Warning Read/Write Error Drive WDC WD400BB-00CFC0 (0x00000002 ch 3) of Array Array1 (0x00000018) has Read Write Error ch3 LBA=45378c0 cmd=20 Disk Status= 51.
11/05/03 06:18:52 Warning Retry Drive Retry drive access in Array Array1 (0x00000018) Drive WDC WD400BB-00CFC0 (0x00000002 ch 3)
11/05/03 06:18:51 Warning Read/Write Error Drive WDC WD400BB-00CFC0 (0x00000002 ch 3) of Array Array1 (0x00000018) has Read Write Error ch3 LBA=4536653 cmd=20 Disk Status= 51.
09/03/03 21:56:30 Error Drive Fail Drive 0x00000002 ch 1 failed
09/03/03 21:56:29 Warning Reserve Sector Error occurred in the reserved sector of the drive 0x00000010 ch -1.
09/03/03 21:56:29 Warning Read/Write Error Drive 0x00000010 ch -1 of Array Array1 (0x00000018) has Read Write Error ch3 LBA=4a8b141 cmd=20 Disk Status= 51.

no drive actually failed, and all of them are now fine, sychronizing the array fixed all read \ write errors, that and getting rid of the hotswap bays

if your data is critical, or your experienceing weird problems
cables is one of the places to troubleshoot

again from dans data
Bit rot
If you've got a major IDE data loss problem, things will be obviously broken. Drives won't be recognised consistently (or at all) on boot, every file operation of any significant size will cause errors, swap file activity will hang the computer.

That's not the kind of problem you're likely to have from a common-or-garden over-length cable, though. When bits only fall on the floor relatively occasionally, the drives will not obviously be the culprit. If the hardware error detection's catching almost all of the foul-ups, all you'll see is strangely slow drive performance. Since drive speed has little impact on most desktop computer tasks, you probably won't notice.

The most heavily accessed part of your drive is very probably going to be the part that holds your Windows swap file. Since the swap file is literally part of your computer's random access memory as far as Windows is concerned, IDE data integrity problems can cause the same sorts of symptoms as faulty RAM.

Many of these symptoms don't look like drive errors at all. Swap file errors won't give you a disk error warning message; your computer will just jam its head enthusiastically up its cloaca and start chewing like mad. If you don't suspect the drive cable, you will then get to spend a significant fraction of your life cursing at the thing and swapping out perfectly OK components, to no avail.

A computer in this state can give the user the "anti-Midas touch" - everything you touch can turn to dung. Any write operation may, or may not, result in small but file-killing errors.

Oh, yes - what's the second-most-accessed single chunk of disk space on a Windows box? Probably the registry, baby. You don't want errors there, either.
Click to expand...

more potential leads (for posterity) > Corrupted Files!?

good cables are cheap insurance, when compared to the type of $$$ we shell out for other components ;)
 
What is the point of this thread?

We've seen evidence that shileded PATA cables offer better performance because of fewer CRC errors - cool

We've seen graphs of shielded vs unshielded PATA cables and 'noise' associated with them (may be linked in a related thread) that show less noise in a shielded cable -cool

We've heard a rant against SATA from a man who is up in arms over the SATA working group's closed SATA standard which destroys this man's track record of 10 years of open and well documented ATA standards. - ok but that's not an 'unbiased' source to say the least.

We've heard some theoretical talk about how SATA reduces EMI interference problems because of fewer lanes and reduced voltage and how the CRC checking is better on SATA drives/interfaces -ok

We've heard some theoretical talk about how SATA increases EMI interference problems because most SATA cables aren't shielded - ok but neither are most PATA cables.

We've heard discussion that inexpensive SATA technology is less reliable than expensive SCSI technology and that cheap $3 SATA cables are less reliable than $250 SCSI cables - not a huge revelation there.

So where is the meaningful information here? Are there benchmarks that show Shielded SATA (not PATA) cables perform better than non-shielded, or tests that show shielded SATA (not PATA) cables produce fewer CRC errors than unshileded cables?

It may very well be true that Shielded SATA cables produce fewer errors than non shileded cables which in turn leads to increased performance... or that unshileded SATA cables are just as bad as PATA cables or worse even - but where is this information?
 
have at it :p
Id appreciate your exhaustive benchmarking efforts on the forums behalf

the point of this thread is purely cautionary, and educational
that cables in general maybe one of the factors if your experiencing problems

in short, I started this thread after I pimped SATA as a reliable (as implemented) standard for over 6 months, but which Ive seen many an issue develop since then

if a new routing scheme or a little homemade shielding can address that great, but first you need to be aware of it ;)
 
Don't get me wrong - I think it's a good thing to point these kind of things out, but I like to have some kind of evidence as well.

Unfortunately I don't have any SATA drives otherwise I would test it for you guys.

I thought the hotswap bay results were interesting - Am I correct in that these errors occured only after the drives were installed hot-swap
(you don't get these errors regularly) and stopped after you did nothing but take them out of the hot-swap bays & re-sync? (no different cables or anything).

thanks.

ps - from GD:

5400 68 MicroDm - 68 MicroDm - 90 ft. $699.00 :eek:
 
yup, used the same flat high quality teflon IDE cables supplied with the card
IDE covers up alot of errors and they arent logged, so comparisons are still somewhat misleading if they where directly attached to the mobo, but with them directly attached to the RAID card again (which are logged) all the errors disappeared
but they where only the read\write errors, not less serious errors

but that is still just indicative, not definitive out of 6 channels only 2 showed any issues, could be that those backplanes where not as good as the others, and since I didnt conduct more exhaustive tests...

for a directly attached HDD ATACT could be employed, Id be very interested in an exhaustive series of tests, the crappy IDE (PATA)cables, good ones, unsheilded SATA and sheilded

but in truth that would just be indicative as well, since EM sources and routing would vary from config to config

so I guess what this thread is really about is illustrative of where things can go wrong, rather than definitive proof on componet X over componet Y
for most people this isnt really much of an issue unless instability or data corruption is actually occuring

PS yeh outrageous, I need a few external SCSI 68 .8mmVHDm to 68 MicroDm - 3 ft. @ $159 each :rolleyes:
but will probably opt for slightly more affordable source but will buy only one and test first before getting more
 
Well in my case it´s impossible to NOT have either a SATA and IDE cable near eachother or two SATA cables near eachother. Which is preferrable? Two Raptors stuck really close to eachother or a RAPTOR and a WD 800 JB stuck to eachother with a fan blowin on them and a single RAPTOR without a fan??
 
Okay, wait a second. The Serial ATA cable was designed under the consideration that it would encounter numerous EMI and RFI sources within the system case. We have several RFI sources in close proximity to the Serial ATA cable:

1. CPU
2. GPU
3. Motherboard switching regulators
4. Power supply switching regulators

and this guy means to say that these high-frequency RFI sources were not carefully considered during the design process? I'm afraid he might be mistaken. Of course, if he provides evidence to the contrary, I will go ahead and consider these shielded cables. Empirical evidence in the form of benchmarks are cool, too.
 
Originally posted by xonik
Of course, if he provides evidence to the contrary, I will go ahead and consider these shielded cables. Empirical evidence in the form of benchmarks are cool, too.
Click to expand...

ATACT Log File SATA
ATACT Log File PATA
Analysis ATACT SATA Log File
This log file is the result of a 94 hour run of ATACT on a SATA
drive. There are 31 errors in this log: 2 data compare errors
(wrong sectors read) and 29 other errors (5 of these resulted in
an ATADRVR timeout error).

First thing to notice is that these errors are grouped around
various times - a few errors over a minute or two and then a few
hours of no errors followed by another group of errors over a few
minute time frame. The errors do not seem to be grouped around
ranges of LBA locations on the media (there is no indicate of a
media problem on this drive).

You must be very careful when looking at errors on a SATA device.
The status reported to the host software by the host controller
hardware can be (usually is?) out of sync with the actual device
status. SATA seems to have the ability to randomize the ATA
status information making it very difficult to determine what is
really happened.

High level summary:

* There are 12 errors that appear to be the result of the host or
device causing a "reset" (SATA COMINIT?) in the middle of a
command.

* There are 8 strange status errors where is appears that the
device has "disappeared" from the interface.

* There are 4 errors when the device appears to be hung with
BSY=1 status during a data transfer command.

* There are 4 errors when the device appears to be hung with
DRQ=1 status during a data transfer command.

* There are 2 data compare errors because the wrong sectors were
read from the device. In both cases the retry of the same
command did not fail. Could this be a case of the command
parameters received by the drive being corrupted? See errors
#23 and #27.

* There is 1 ABRT error that appears to be the result of the
device receiving a corrupted command. In this case the Sector
Number register appears to have changed to FFH making the
command invalid. See error #30.

These are all very serious errors and errors that are extremely
unlikely on a PATA interface. If these errors happened on PATA
this system or device would never qualify to be shipped to
customers. Why are SATA devices with these error conditions in
your local computer store?

Here is a summary of each error...

MORE>
Click to expand...

Hale Landis help to develop the ATA\ATAPI standard
but painting him as a PATA advocate would be incorrect
hes is an ATA advocate be it Parallel or Serial
he is simply pointing out that at least part of the time with drives he has tested something is up.
 
i like my shielded/terminated U160 cables :p
 
Menelmarar said:
but regular PATA cables aren't shielded either? whats the problem?
Click to expand...

same problem :p
read the links

your cheap run of the mill IDE flat cable is made with PVC, the high quality ones are made with Teflon or Thermoplastic Olefin (same with flat SCSI) high quality sheilded cables are made with grounded wire mesh sleeves and a protective layer, in addition to how the data wires are layed up with the ground wires, very very common in SCSI externals or round internals, and there are a few IDE rounds made like that

IDE is pretty good at shouting through noise, but it can be an issue
see > Corruption 101 > Cables
 
Everyone laughed at me, yelled at me, or got angry at me for using a roll of tinfoil to shield my SATA cables (PATA cables soon too), but after the performance and reliability boost, I'd say it was worth it. :p

Now I need to get a better CPU. :(
 
Okay so here's my dilemma:

I have a single 74 Gb Raptor in my system, as stated in the specs in my sig. I have about 45 Gb of mp3 data ripped directly from CD using EAC and LAME to convert. My library is about 7500 tracks and growing steadily.

That said, My raptor is completely full. I can no longer use the old (noisy and thus replaced with the nice quiet and fast raptor) WD400 to backup all my "critical" data. So, I have come to the conclusion that I MUST add storage to my box.

So, I have options to consider. I can purchase another Raptor and set up a RAID0, and a 160Gb drive for backup (is that RAID0+1? not sure yet), or I can just get a 160 gb drive for storage and forget about the backup.

Obviously it is a great idea to backup so I'm probably gonna backup no matter what I do. The real problem arises once I read this (and others) thread about SATA and data corruption/performance-sucking errors. I have the IC7-MAX3 and the SATA connectors are about 2-3 inches from the SATA connectors on the back of my existing RAPTOR. The cables are obviouly MUCH longer, and as I am looking at them right now, just kinda munched together behind the drive, resting in some areas on the case floor.

Adding another raptor will just make the mess of cabling much worse, and could cause serious problems when used in a RAID0... is this a correct assesment?

What should be done in this case? I mean, I really only need the SATA cabling to be about 5 inches long, but I'm forced to use cables that are what, at least a foot long?

Should I just get the raptor and the backup drive, shield the SATA cables using tinfoil and electrical tape, and pray for the best?

All of the information provided by Ice Czar and others is very enlightening, but I am unsure what the actual action is that should be taken, or of a good solid work-around for the time being.

Thanks for any pointers guys, you all ROCK!!!
 
any array will increase the potential for signaling issues
simply because of the extra number of cables

there are shielded cables available,
and there is the potential to shield your own
and there is the mechanisms in the protocol itself (ATA) to catch erors

while the issues raised are real, they shouldnt be a criteria to adoption
simply something to be aware of and to test for
SATA has proved itself as reliable as PATA
not the best possible recommendation :p

you can hunt for shorter cables, shield, and route
and then you can test, but I wouldnt make the determination to buy or not buy an array based on the cables
in the event you do detect an issue or suspect its incurring on the performance potential, then you can look at additional measures

I would question why you want to adopt a RAID 0 however
(as a note a RAID 0+1 is what is called a nested array, and would require at least 4 matched drives, in effect two RAID 0s where the second set mirrors the first)
RAID 0 is performance space, not storage space
a truely redundant array would likely serve your needs better, or simply single HDDs
 
damn SATA cables. I wish I woulda known this sooner. My raptor just died under 30 days. I had my 2 SATA cables running pretty damn close if not touching each other. I just got my new one and its so frickin' loud. I'm gonna foil tape mine to tomorrow. thanks for the knowledge

As far as ATACT Log File SATA. 94 HOURS! SOrry i'll pass
 
I wanted to go with the RAID0 for speed especially loading levels in games and installing applications. Really, I would just do a straight backup with a 160gb drive.

After a little thought, however, I think I'll just get a large storage drive and skip the RAID. I don't think it would be too noticable vs. the risk. Thanks for the input.
 
keep in mind the issues addressed in the caution
date from the original release of SATA, its had awhile to mature
when I originally posted this however, there was a widely held belief
largelty from my own doing that SATA was a magic bullet for reliability
this is more to make members aware that there are no magic bullets and that signal issues can be a contributing factor, its something you especially worry about when employing hotswap caddies ;)
 
aren't some psu sleeving kits metal mesh? would make good shielding for sata cables, yes???
 
yup if they are grounded and are real metal,
how well they will work dependent on their magnetic permiability
the absolute best stuff is mu-metal
commonly employed as shielding in all sorts of electronics
after that copper tape is commonly used

a normal 40 wire IDE cable (ATA33) is comprised of data wires
an 80 wire cable (ATA66 > 133) intersperses an additional 40 grounded cables
which substantially reduces interference between the data wires
however the insulation\shielding at other angles is lacking

mu-metal linkage & info
http://digilander.libero.it/paeng/what_mu_metal.htm
http://www.vacgen.com/asp/catalogue...en.com/catalogue/chambers/mumetal.htm&frame=1

Mu-metal is a common name for an 80% nickel, 4% molybdenum, 16% iron alloy with superbly high magnetic permeability. Carpenter Technology (a steel company) calls it HyPerm 80, and another name is Permendur. You can get it from CarTech, from Scientific Alloys in RI, probably from Specialty Steel & Forge: but your best bet for small quantities might be to do a web search using "magnetic shielding" as a topic.

It is strongly ferromagnetic, by the way. That's how it works- the field is held in the shield, away from the device you are trying to protect. - Lee Gearhart


http://en.wikipedia.org/wiki/Nickel
Nickel is one of the five ferromagnetic elements. Because of the precise alloy used, the US "nickel" coin is not ferromagnetic, while the Canadian coin of the same name is.
http://en.wikipedia.org/wiki/Mu-metal
Mu-metal is a nickel-iron alloy (77% nickel, 15% iron, plus copper and molybdenum) that is very efficient for screening magnetic fields. It is used to shield vacuum chambers for experiments with low-energy electrons, to shield magnetic resonance imaging equipment, and to shield the magnetometers used in magnetoencephalography and magnetocardiography.

The name of the material refers to the Greek letter μ, which is the symbol for magnetic permeability. Mu-metal has a high value of μ.


Magnetic Shielding Foil: 16" wide (Cat. # A276) .... $18.95/linear ft
Used for years in industry to shield delicate electronic components from EMFs, MuMetal magnetic shielding is now available at affordable prices for home and office use. This mumetal alloy (80% nickel) is easy to trim with scissors and shape by hand. Can be formed into magnetic barriers on cellular phones, microwave ovens, doorbell transformers, VDTs, buried wiring, and more. With snug fitting shapes, get as much as 75% attenuation of the magnetic field with one thickness. Use multiple layers for even greater reduction. Foil is 0.004" in thickness and 16" wide and can be ordered in any length. (We recommend the use of a gaussmeter to determine the proper shape and positioning of the magnetic shield, and to confirm that the fields have been adequately reduced.)
 
I was thinking that the stainless steel braided ones would work on the cheap if you happened to have some laying around, sadly I don't :( I also don't have SATA drives yet. just ordered a 200GB PATA for my fileserver. (200GB WD2000BB at newegg for $103.50:eek: ) I still like PATA ;)
 
it damn common to see copper taped flat SCSI cables in enterprise storage
(having disassembled a few media shelves ect)
 
Ice Czar said:
(having disassembled a few media shelves ect)
Click to expand...
Johnny Five(short circuit) said:
Error! Grashopper dissasemble! Reassemble, Stephanie!
Click to expand...
:p
that goes through my head every time whenever someone says disassembled. :p
 
Just an added thought incase some one missed it, proper EMI / RFI shielding works best when grounded only on one end. Ground both ends and you complete a portion of a signal path you are trying to end.

Just slightly off topic but some what relevant are the informational parallels in wire, shielding, dielectrics and insulators we found essential years ago back in the Audio business are now showing up in a business where raw data is the critical component. Probably some lessons to be re-learned from the “old” days ;)
 
Well, there are a lot of electrical components and cables in a modern computer now. It's not really a surprise that shielding is becoming an issue. i'm going to be sure to shield all of my SATA cables from now on, it's saved me a lot of time and effort. I used to have to reinstall windows regularly, but since I've shielded my cables, it's not an issue.

I got to use an unshileded cable to my bass amp once. I was getting so much random crap, so I switched to a Shileded cable. Then I found out that there was no shielding in the amplifier, and I could hear the noise generated from a neighbor's power drill through my speaker. ;)
 
Ice Czar said:
any array will increase the potential for signaling issues
simply because of the extra number of cables

there are shielded cables available,
and there is the potential to shield your own
and there is the mechanisms in the protocol itself (ATA) to catch erors

while the issues raised are real, they shouldnt be a criteria to adoption
simply something to be aware of and to test for
SATA has proved itself as reliable as PATA
not the best possible recommendation :p

you can hunt for shorter cables, shield, and route
and then you can test, but I wouldnt make the determination to buy or not buy an array based on the cables
in the event you do detect an issue or suspect its incurring on the performance potential, then you can look at additional measures

I would question why you want to adopt a RAID 0 however
(as a note a RAID 0+1 is what is called a nested array, and would require at least 4 matched drives, in effect two RAID 0s where the second set mirrors the first)
RAID 0 is performance space, not storage space
a truely redundant array would likely serve your needs better, or simply single HDDs
Click to expand...

Wow, Ice...do you write free form geek poetry as a day job, or is it just kind of a hobby? :D
 
I can’t tell if it’s Haiku for geeks

Or Iambic Pentameter for geeks

Or, perhaps, it is just his very own inimitable style

I’ll take the latter. ;)
 
I dunno if I buy this one or not..in my own rig, I did ALOT of testing for SATA corruption, due to my NF7-S when I first got it. My SATA drive was corrupting alot, and it turned out I had to change a bios setting to fix it. (damn if I can remember the exact setting.. p2p discard time I believe. had to change it to 1ms) Anyway, I definately could make it corrupt when needed, by compressing LARGE amounts of data into a rar, copy that to another partion, and then unrar it, and check the SFV values I made on the files.. After the bios setting was changed, I didn't have this problem any longer..

Now, here's the relevant part.. If what is said is true about SATA cables, then I should still have corruption problems, since my SATA cable is rolled up into a loop, and zip tied, so the cable takes up less space.. It also touches my 6800 GT, oc'ed to Ultra levels, which I'm sure is a major source of EMI in my case, and it touches a power cable or 2, and a floppy cable.. Non of that is shielded.. yet corruption still doesn't exist..

Now, am I saying it's not possible? far from it.. but I don't think that the average user really needs to worry about this, and probably not enterprise users either, since MAJOR SCSI manufactures (seagate, adaptec, LSI) are working on SAS. I'd think they'd be doing they're own data corruption tests with EMI in a server environment, as part of them bringing these products to market.. And the technology used in SAS is pretty much the same thing as SATA..


I just don't see this as a real concern for the majority of the ppl out there.. Unless of course you have a tesla coil installed in your box, and your SATA cables are touching it.. ;)
 
Many times your average user attributes anomalies to everything but the correct source. I agree for most part that one would think we would hear a lot more about this. I wonder however how many hard drives, motherboards or other components are returned simply because an inexperienced builder just plain followed bad building (wire routing) practices.

If you look at the review sections of say, New Egg how many times have you seen a known great product with a few reviews from totally unhappy wannabe builders? In the case of motherboards I see a lot of SATA problems and if you follow to the hard drive section you can find the same thing. If in fact this is a more prevalent problem then originally thought it could also explain those same review problems when SATA with RAID is mentioned. Statistically you are probably more then doubling your potential for issues if you go RAID, and assuming there really is a problem.

Barnaby may have actually created the cure (with his cable rolled up in a loop), an open core choke at the perfect frequency to “null” any stray EMI / RFI in his cable’s vicinity. ;)

Tesla coil optional of course :D
 
LoneWolf said:
Wow, Ice...do you write free form geek poetry as a day job, or is it just kind of a hobby? :D
Click to expand...

BillR said:
I can’t tell if it’s Haiku for geeks

Or Iambic Pentameter for geeks

Or, perhaps, it is just his very own inimitable style

I’ll take the latter. ;)
Click to expand...

LOL

27 years of

A D V E R T I S I N G

:p

a trade that singularly prepared me to sort through the hyperbol for the facts
and then translate them into something understandable

forgot to mention the single ground, thanks BillR ;)
like any faraday cage a single ground point is by far the best solution
 
You must log in or register to reply here.
Back
Top