Is it safe to have a 6 x 2.5" SSD using 1 x molex in 1 cage

Happy Hopping

Happy Hopping

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iStarUSA have this all along, a 4 x 2.5" SSD, using 1 molex plug

http://www.newegg.com/Product/Product.aspx?Item=N82E16816215223

now, guess what? They now have a 6 x 2.5" SSD, all using 1 molex plug

http://www.newegg.com/Product/Product.aspx?Item=N82E16816215222

Look, I know SSD use very little electricity, but 6 in 1? I don't want to play around w/ not enough electricity on my SSD.

Also, why on earth is the price so high? $76 to $84 for a metal cage?

this brand is only $49 and they seems to play it safe to go w/ 4 in 1 only

http://www.newegg.com/Product/Product.aspx?Item=N82E16816710003
 
One molex cable should be able to provide between 50-100 watts of power, depending on the cable gauge.

You will be more than fine with 4 to 6 SSDs on a single cable. In fact, you could probably get away with 30+ SSDs on a single cable, they tend to only use between 0.5 to 3 watts of power each.
 
but different part of that power supply gives different current at ?? Voltage. The power supply favors video card voltage. Then a good portion goes to SATA.

As to molex, I don't know what the watt is in my machine, but 50 to 100W sounds high, doesn't it?
 
Red Falcon said:
One molex cable should be able to provide between 50-100 watts of power, depending on the cable gauge.

You will be more than fine with 4 to 6 SSDs on a single cable. In fact, you could probably get away with 30+ SSDs on a single cable, they tend to only use between 0.5 to 3 watts of power each.
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This. You could even use traditional mechanical HDs and be ok here. What I don't understand is the need to have hot swappable SSDs. I have one as a boot drive. I never need to remove it... If I had a second SSD, I would RAID 0 them and never have to remove it. I suppose if I had two computers, with ... no... never mind... I still don't understand the need.
 
Happy Hopping said:
As to molex, I don't know what the watt is in my machine, but 50 to 100W sounds high, doesn't it?
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14 gauge wires can handle around 6 amps
16 gauge wires can handle around 4 amps

volts x amps = watts
so a single 12v wire can supply 50watts (16ga), to 70watts (14ga).

hard drives run on a combo of 5v and 12v, so the load will be spread over more than one single wire. total capacity for a molex lead is probably around 70 to 100 watts (each lead might have more then one molex connector on it, however the 70 to 100 watt capacity is for the entire wire, not each connection on the wire as there are usually several).

overestimating- at 5w per SSD, you can run 14 to 20 SSDs off of a single molex cable. it doesnt sound very high if you do the math...
 
Happy Hopping said:
but different part of that power supply gives different current at ?? Voltage. The power supply favors video card voltage. Then a good portion goes to SATA.

As to molex, I don't know what the watt is in my machine, but 50 to 100W sounds high, doesn't it?
Click to expand...

I'm not sure how you have been here for almost 8 years and don't know this stuff. :p

You need to know what your 12v/5v/3.3v rail amps are and total PSU sustained wattage is.
No, 50-100 watts is not that much for a modern PSU, unless you are running a PSU which is sub-300 watts.

PSU's do not favor "video card voltage" as you so call it. I think you mean the 12v rail, which SSDs do in fact utilize, along with the 5v and 3.3v rail, as do modern mechanical HDDs.


You really need to learn a thing or two about PSUs before you continue though. We don't want you to blow up your system! :eek:
 
Negative Decibel said:
This. You could even use traditional mechanical HDs and be ok here. What I don't understand is the need to have hot swappable SSDs. I have one as a boot drive. I never need to remove it... If I had a second SSD, I would RAID 0 them and never have to remove it. I suppose if I had two computers, with ... no... never mind... I still don't understand the need.
Click to expand...

I think they are using SSD as server drives
 
Red Falcon said:
PSU's do not favor "video card voltage" as you so call it. I think you mean the 12v rail, which SSDs do in fact utilize, along with the 5v and 3.3v rail, as do modern mechanical HDDs.
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I was under the impression that 2.5 inch SSDs like 2.5 inch hard drives ran off 5V only because 12V wasn't guaranteed to be available in laptops and 3.3V wasn't guaranteed to be available in desktops.

Do you have evidence to the contary?
 
plugwash said:
I was under the impression that 2.5 inch SSDs like 2.5 inch hard drives ran off 5V only because 12V wasn't guaranteed to be available in laptops and 3.3V wasn't guaranteed to be available in desktops.

Do you have evidence to the contary?
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All the 2.5" SSDs I can find use 5V only, and 1.8" use 3.3V. None use 12V that I can find.
 
plugwash said:
I was under the impression that 2.5 inch SSDs like 2.5 inch hard drives ran off 5V only because 12V wasn't guaranteed to be available in laptops and 3.3V wasn't guaranteed to be available in desktops.

Do you have evidence to the contary?
Click to expand...

All modern PSUs in the last 10 years have 3.3v rails, so yes, desktops can easily run multiple SSDs on a single cable.
You really, really, need to do some research on this before you continue.

You are correct though, as SSDs to my knowledge only run off of 5v and/or 3.3v, and very few run off of 12v (enterprise versions only), but they sip so little power that it would take many working in tandem to overload a cable or voltage rail.
 
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Radical said:
All the 2.5" SSDs I can find use 5V only, and 1.8" use 3.3V. None use 12V that I can find.
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Some of the enterprise-grade SSDs (PCI-E) will utilize the 12v rail, but it still does not have a very high load.
 
Red Falcon said:
I'm not sure how you have been here for almost 8 years and don't know this stuff. :p
......................
PSU's do not favor "video card voltage" as you so call it. I think you mean the 12v rail, which SSDs do in fact utilize, along with the 5v and 3.3v rail, as do modern mechanical HDDs.


You really need to learn a thing or two about PSUs before you continue though. We don't want you to blow up your system! :eek:
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odd that you would say to the poster:

You really, really, need to do some research on this before you continue.
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when he was correcting you on the underlined statement that you made above. they in fact do not use the 12v rail.
maybe you misunderstood what he was saying.

it is very important for users to understand that the SSDs do not use the 12v rail, as it would lead to incorrect measurements of power attainable.
 
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Computurd said:
odd that you would say to the poster:



when he was correcting you on the underlined statement that you made above. they in fact do not use the 12v rail.
maybe you misunderstood what he was saying.

it is very important for users to understand that the SSDs do not use the 12v rail, as it would lead to incorrect measurements of power attainable.
Click to expand...

lol
Some enterprise-grade SSDs use the 12v rail, mainly the PCI-E models.

They are very rare though. If I can find a PDF on one of them, I will definitely post it here.

The majority of SSDs do indeed utilize the 5v or 3.3v rail, though.

EDIT:

Uses all three rails:
http://www.grandmax.net/2010/09/photofasts-lsi-pci-express-ssd-drive.html
http://www.photofast.se/Product/Discontinued/PCIe/Promise.html
 
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well yes, PCIe relies on power quite a bit form the 12v. thats why they refer to it as 'gpu power' in some circles. that is more related to the PCIe spec, than the drive itself requiring it imo.
SSD do have some extremely small power demands, that is one of the things that makes them so darn desirable!
I have ran 16 SSDs and 2 HDD off of one wire, for the record :) i use 4 way molex splitters to sata power splitters.
i wonder how many would be max for one line. I do have a 1500 Watt power supply though, with uber powerful rails.
 
I have ran 16 SSDs and 2 HDD off of one wire, for the record i use 4 way molex splitters to sata power splitters.
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Definitely, so it can be done. btw, I meant the OP needed to learn more about PSUs, not you. ;)
As for the SATA-power SSDs, they do in fact only use the 5v and 3.3v, perhaps I should have specified to make things clearer.
 
Computurd said:
I have ran 16 SSDs and 2 HDD off of one wire, for the record :) i use 4 way molex splitters to sata power splitters.
i wonder how many would be max for one line. I do have a 1500 Watt power supply though, with uber powerful rails.
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how long have you been doing that?

I still haven't own a SSD yet, so let me ask a primitive question, in the case of hard drive, we have Transient response voltage, so I assume you run the above fine at Steady State Voltage, but I am wondering about Transient response voltage

Now, I assume SSD has no transient response voltage, but your 2 hard drive does.
 
Red Falcon said:
All modern PSUs in the last 10 years have 3.3v rails
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The PSU has a 3.3V rail but it's far from gauranteed that every SATA connector in a machine will have a connection to it (most drive cages still seem to use molex connectors for power in). So unless drive vendors want a load of upset users they can't really use 3.3V on 2.5 inch drives (1.8 inch drives do use 3.3V but those don't generally get used in desktops).

so yes, desktops can easily run multiple SSDs on a single cable.
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According to anandtech SSDs go up to about 5W under load. At 5V that is 1A per drive http://www.anandtech.com/show/4253/the-crucial-m4-micron-c400-ssd-review/11 . Most current PSUs (almost regardless of total wattage) have arround 20A on the 5V line

So at drive counts you would normally find in a desktop you will be fine but if you are trying to build a monster SSD array and you intend to load it heavilly you will have to start thinking carefully about your system's 5V load.
 
plugwash said:
According to anandtech SSDs go up to about 5W under load. At 5V that is 1A per drive http://www.anandtech.com/show/4253/the-crucial-m4-micron-c400-ssd-review/11 . Most current PSUs (almost regardless of total wattage) have arround 20A on the 5V line

So at drive counts you would normally find in a desktop you will be fine but if you are trying to build a monster SSD array and you intend to load it heavilly you will have to start thinking carefully about your system's 5V load.
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That's a good point, I never looked at it that way.

I have seen PSU's which are 700+ watts with a very weak 12v rail, but incredibly strong 5v and 3.3v rails. Perhaps this type of PSU should be the choice for SSD enthusiasts. ;)
 
if running the drives in raid 0 i would honestly feel more comfortable with the drives all coming from one line.
 
From an wiring standpoint, you will know when a wire or connector is overloaded because it will get hot. A 2.13mm molex pin I believe is good for around 8 amps, and thus will be the weakest link in the circuit assuming 18ga wire which has an ampacity of 14 amps. Basically what I'm saying is check for heat on the molex connector if you're concerned.

Dustin
 
I have 8 disks of type 3.5" on one molex. It works fine. Has run it for a year or two now.

But when I boot up the PC, there is some stuttering sounds from the disks. Maybe it is because of power is not really enough? But after the stuttering sound, everything is fine.
 
Could be a sign of momentary low voltage on the 12V as they all spin up at the same time. Current demand lowers dramatically once they're all up to speed, so you're probably fine electrically but I don't know how good or bad this might be for the drives themselves. I'd try to find a way to split that load up, and check the molex for blackness (bad). Once they start burning away, it just gets worse as the contact area decreases.
 
@dustNbone
Staggered boot up boots one disk at a time, even if I have 8 disks. I have heard.

So, how can I get this staggered bootup? My raid is actually booted up, once per month. Then I use the raid for a few hours, and the power down immediately. So my raid has been powered on, just a few hours in total. I hope this helps against these problems you mentioned.
 
Staggered spinup will be a function of the RAID controller, somewhere in it's setup/BIOS menu. Occasional use doesn't really help you here, as it's during the spinup process that you may be experiencing the problem, and this is when you will get burning at the molex. Once everything spins up, and power demand is much lower, even a connector that's a little burned up will probably be fine. as ampacity is a product of contact area (effective conductor size at the connection). If you have staggered spinup you're probably fine though. You should be able to hear each start individually if this is the case, if one of them is making a funny noise (assuming they're identical drives), I'd be suspicious of that particular drive rather than a global problem such as power.
 
dandragonrage said:
Wrong. Houses use 14 gauge for 15A circuits, you know. P.S. I think the PSU cables tend to be 18 gauge, not 16.
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House wiring is A/C - that is not the same as DC current and heats differently due to the cycling. There is a very good reason why we use A/C for transmission of power across long distances, but D/C for short power runs.

Wire ratings are quite arbitrary anyway; the length of the wire has as much to do with it's current rating as the wires gauge does, and the rating is going to vary based on your specs for % of power acceptable to be lost along with type of insulation, etc. General rule of thumb, If you're talking about 2 foot or less of wire, you'll be fine with 10-15 amps on a 16ga wire. Loss due to resistance will increase across longer lengths of wire - resistance loss equates to heat generation...and so you start needing thicker wire or shorter wire lengths when pulling higher currents through the wire.

Long story short, yes, you could run 20 ssd's comfortably off of a single molex plug from your power supply. There will be some measurable voltage loss but not enough to matter to your SSD's, and certainly not enough current involved to melt insulation on the wiring.
It's worth noting that the required wattage @12volts would generate much less heating than the same wattage @ 5v...that same wattage @ 3.3v will produce more heat. So it's worth noting that the amperage is the important number to keep up with, and since ssd's do use lower voltage inputs, they will pull more amperage than one might expect if they used 12v power. For example, 3 watts @ 12v is only 0.25amps. 3 watts # 3volts is an entire amp. :) Watts = amps*volts, but amps account for 90% of the heat generated during power transmission. High voltage, lower current = cool. High current = hot, even with quite low voltages involved. Even with that said, however, the amounts of power involved would still comfortably allow 15-20 ssd's to be connected to 1 molex plug if they were using 5v.
 
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