help me understand hard drive speeds, 2 hard drives

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multi-tasking_guy

Limp Gawd
Joined
Jun 16, 2017
Messages
142
Hi!

I have 2 laptop hard drives, im a little confused to why the slower rpm hard drive is faster than the other one。

i thought the slower rpm would equal slower drive but in my case it is the slower one is faster.

One hard drive is 3.0 gps and the other one is 6.0gps double the speed.

The reason about all this is, im trying to figure out which one to use for my laptop. I want to use the fastest hard drive.

Im a little confused. Here are the specs on my 2 hard drives

Screenshots_2018-02-04-08-56-40.png Screenshots_2018-02-04-08-55-53.png


help me thanks
 
One hard drive is 3.0 gps and the other one is 6.0gps double the speed.
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That is all theoretical since neither of them can read or write at more than SATA I speed (maxes out at 150 MB/s).

I want to use the fastest hard drive.
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The 6.0gps drive is likely newer than the 3.0 gps drive which may make it slightly faster.
 
multi-tasking_guy said:
I thought one of the hard drives was sata II and the other one was sata III
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They are. Does not really make much of a difference with hard drives since the heads don't read or write at either of these speeds. Neither of these drives even hit SATA II speed.
 
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Stop making a hash of this explanation.

OP, what you're looking at is the interface speed, not the actual data transfer rates of those hard drives.

The 7200RPM drive will be faster than the 5400RPM one, but neither of them can send data through the interface at speeds anywhere near 3 Gbps, let alone 6.

Think of it like having two Volkswagen beetles on two roads, one with a 300MPH speed limit, one with a 600MPH speed limit.

Doesn't matter what the speed limit is, all that matters is which beetle has the bigger engine, because neither of them are ever going to be able to hit the limit on either road.
 
Original post

First:
none of the two seem to be a 5400RPM drive. wher di you get 5400rpm from ?

Second:
The 3gb and 6gb are just the speed of the connecting cable/communicating interface. The drivestill need to pull the dat aoff the actual plate which is hig likely slower than the cable speed


multi-tasking_guy said:
So where can i find the actual data transfer rates, i don't see it anywhere in the screenshot i posted
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You need to run a benchmark on them. but they are most likely very identical.
 
The easiest way is to search for benchmarks in reviews. With that said the manufacturer will post technical specs that will have the maximum media transfer rate listed if you really want to see that. They should be similar.
 
I am more confused

how can you guys say the max speed is 150mbps, but then cant give me the actual transfer rates without the benchmark, where exactly did the 150mps come from if its not on the spec sheet anywhere



so what the point of the 6.0 and 3.0gb/s in the datasheet, if it cant even reach those speeds
 
so what the point of the 6.0 and 3.0gb/s in the datasheet, if it cant even reach those speeds
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To confuse some people to think their drive will be twice as fast as the old so that they replace the old..

The SATA II and SATA III interfaces only really help SSDs. They are a marginal benefit to hard drives.

With that said newer 3.5 inch drives with larger than 1TB platters do hit around 220 MB /s on the outer tracks so that there is some benefit to SATA II.
 
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multi-tasking_guy said:
I am more confused
how can you guys say the max speed is 150mbps, but then cant give me the actual transfer rates without the benchmark, where exactly did the 150mps come from if its not on the spec sheet anywhere
so what the point of the 6.0 and 3.0gb/s in the datasheet, if it cant even reach those speeds
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Hopefully this will help out. First lets get the rates, so 150 Mbps is Mega bits per second, while 150 MBs is Mega bytes per second. The interface to the hard drive is SATA, and what you were asking is SATA 2 and SATA 3, which some people commonly call that SATA 3 Gbps and SATA 6 Gbps. That is only the interface to the drive, the point where the drive connects to the system. Generally speaking, the interface isn't faster in day to day stuff that you would notice. The spin rate of the drive is next, with 7200 RPM being standard for desktops while most of the time, laptops comes with slower spin speeds of 5400 RPM. The faster the spin speed, generally makes it a faster drive, (faster feeling in general use as well). Either way, an SSD in your laptop would probably be a better upgrade than either of those two disks.
 
multi-tasking_guy said:
Hi!

I have 2 laptop hard drives, im a little confused to why the slower rpm hard drive is faster than the other one。

i thought the slower rpm would equal slower drive but in my case it is the slower one is faster.

One hard drive is 3.0 gps and the other one is 6.0gps double the speed.

The reason about all this is, im trying to figure out which one to use for my laptop. I want to use the fastest hard drive.

Im a little confused. Here are the specs on my 2 hard drives

View attachment 52872 View attachment 52873


help me thanks
Click to expand...
Like others have said the 1.5 and 3gbs or sata 2 or 3 is just the link speed

Hdd manufacturers don't norm list there actual achievable transfer rates

I'm not sure why you are trying to go this far into a laptop HDD speeds (mainly as you dontd undeunders) so youyreally you should be comparing, is it a HDD or is it an SSD

HDD will be slow, any SSD will be fast it's that simple

you can't really buy a slow SSD now, and the ones that are technically slow are still 10-1000x faster then a hdd, especially at random access which is the main problem with a HDD is if they're doing more than one thing at a time or accessing lots of very small files they just fall apart performance wise ( especially noticeable in Windows 10 and Vista as it can be particularly aggressive on the hard drive as it doesn't do background tasks as background disk IO priority which Windows 7 and 8 do)

where is SSD a direct access to the data and has no spinning components so it is near instant access where as a hdd has to do one full spin before it can read the data
 
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Ok but here is says:

Difference between SATA I, SATA II and SATA III
What is the difference between SATA I, SATA II and SATA III?

SATA I (revision 1.x) interface, formally known as SATA 1.5Gb/s, is the first generation SATA interface running at 1.5 Gb/s. The bandwidth throughput, which is supported by the interface, is up to 150MB/s.

SATA II (revision 2.x) interface, formally known as SATA 3Gb/s, is a second generation SATA interface running at 3.0 Gb/s. The bandwidth throughput, which is supported by the interface, is up to 300MB/s.

SATA III (revision 3.x) interface, formally known as SATA 6Gb/s, is a third generation SATA interface running at 6.0Gb/s. The bandwidth throughput, which is supported by the interface, is up to 600MB/s. This interface is backwards compatible with SATA 3 Gb/s interface.

SATA II specifications provide backward compatibility to function on SATA I ports. SATA III specifications provide backward compatibility to function on SATA I and SATA II ports. However, the maximum speed of the drive will be slower due to the lower speed limitations of the port.

Example: SanDisk Extreme SSD, which supports SATA 6Gb/s interface and when connected to SATA 6Gb/s port, can reach up to 550/520MB/s sequential read and sequential write speed rates respectively. However, when the drive is connected to SATA 3 Gb/s port, it can reach up to 285/275MB/s sequential read and sequential write speed rates respectively.
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so you guys are wrong,

my hard drives are generation second and third, 3.0 and 6.0

so they are capable of going that fast,

so its the port on my motherboard that is slowing them down>?
 
so you guys are wrong
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I am absolutely positively not wrong. I have used 100s to 1000s of drives over the last 30+ years. I know how they perform.


It does not matter what your motherboard or the SATA port will do neither hard drive will read or write at faster than SATA I speed. That is as fast as it can read or write the data from the platters to the heads.

Newer 3.5 inch drives with larger than 1TB platters can read and write up to about 250 MB/s but none of them are 2.5 inch laptop drives.

Here is a data sheet for a 12TB Seagate 7200 RPM Performance drive. It is the fastest SATA hard disk I know.

https://www.seagate.com/www-content/datasheets/pdfs/barracuda-pro-12-tbDS1901-7-1707US-en_US.pdf

One second page of the specifications it says "Max. Sustained Transfer Rate OD" of 250 MB/s. That is the maximum read / write performance of the drive. This performance is achieved mainly by having higher density platters than previous generation drives.

so its the port on my motherboard that is slowing them down
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It's the drive itself. The heads can only read / write so fast to the media.
 
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multi-tasking_guy said:
so you guys are wrong,
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It is one thing to come in here seeking help, but you don't already stated you didn't know. Our shit works and works well, hence why we are trying to help you out. Telling us we are wrong when you have the problem is silly. You need to do a lot more reading on the subject and then do some testing to figure stuff out.
 
Yeah, the only person wrong here is OP.

For a SATA 1 link, some extremely high end mechanical hard drives can move data from the platters at a rate of more than 150MB/s. At that point, the 150MB/s speed limit of a SATA 1 link becomes a bottleneck in performance.

A SATA 2 link has a higher speed limit, no mechanical hard drive can hope to reach that speed limit, and thus there is no bottleneck.

A SATA 3 Link has an even higher speed limit, no mechanical hard drive can hope to reach that speed limit, and thus there is no bottleneck.

Case closed.
 
SATA interface speed is like a pipe size, which is just a capability. Speed comes from the actual hardware in play. I haven't checked speeds of the latest drives, but the last fastest hard drives on the market I've dealt with are around 225MBps, it is possible some of the new largest ones may be up to 250 or a little more now, but that's it. Only SSDs are faster at this time. Period.

If you see your transfer rate in windows showing faster from a HDD to a HDD it's due to caching.
 
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4tb7200rpm Dell Sas ATTO.PNG
1-2tb 10k Dell Sas ATTO.PNG
600gb 15k Dell Sas ATTO.PNG
Intel S3710 800gb Sata ATTO.PNG
1.6tb Dell SAS 12gbs SSD H730 ATTO.PNG



Here are some benchmarks just for you to compare. All done on a 12gb/s SAS controller (The SATA SSD is limited to 6gb/s rate).
So the interface maximum for most panels is 12gb/s and as you can see just about nothing except the highest end SSDs overrun the 6gb/s bus rate, and none of the drives that are not SSD can over run a 3gb/s bus

7200rpm drive with 12gb/s interface
10,000rpm drive with 12gb/s interface
15,000rpm drive with 12gb/s interface
SSD drive with 6gb/s interface
SSD drive with 12gb/s interface
 
Here is what you would have for Standard application generated, single threaded non compressible sustained writes under windows:
This is specifically useful as it is what your would actually get speed wise for a lot of real world copy / write, application launch situations when doing just 1 thing at a time.
These are the same drives as the above benchmarks.

7200rpm drive with 12gb/s interface
10,000rpm drive with 12gb/s interface
15,000rpm drive with 12gb/s interface
SSD drive with 6gb/s interface
SSD drive with 12gb/s interface

4tb7200rpm Dell Sas H2Wtest.PNG
1-2tb 10k Dell Sas H2wtest.PNG
600gb 15k Dell Sas HW2test.PNG
Intel S3710 800gb Sata HW2test.PNG
1.6tb dell SAS hw2test.PNG
 
GlacierNine said:
Hey, it wouldn't be the first time a high post count and complete idiocy were combined on [H].

It's just not at all happening in this thread.
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True, but most of the time at least from what I've seen when people give advice on this board it's usually sound. And any incorrect advice is quickly pounced upon and corrected by someone.
 
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