Intel DQ77KB - DC Power - Hard Drives

J

JMcQueen

Limp Gawd
Joined
Sep 27, 2008
Messages
146
I have one of these knocking around not doing anything (with an i3 and 4gb ram) and was wondering if anyone knew how many hard drives it would be capable of powering if I was to use an AOC to add additional usb sockets?

Before I sell it I was wondering if I could use it to replace my ageing home server but I'd need to be able to run four or five 4tb drivers off it.
 
It all depends on the size of the brick you use, as well as the drives. I have 4 x 3 TB, and 1 x 4TB drive on mine, with an HBA card that staggers the powerup of the drives on a cold boot.
 
Great, I'd been looking around the web and had just about given up on the idea. Can I ask what size brick and which card you are using?
 
Dell FA130PE1-00 (PA-4E), 130W brick. LSI Internal SATA/SAS 9201-8i ~ $75 on ebay (they are OEM only, same as an 9211-8i but IT mode only (no raid).

I slotted the PCIe socket so the card fits - 4x slot w/ 8x card. The rest of my system specs are in my sig.
 
Thanks. That card may be overkill for me though as I dont need raid, I only need to be able to add more drives that the board has sockets.
 
Well if you're only looking for sata connectors, the board has 4. You can also get a 5th with a mSATA to sata adapter board. http://www.amazon.com/dp/B009UDAINW?psc=1

I used a LSI card because they work well for passing through to VM's in esxi.
 
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I could actually just buy a msata ssd and use the other four for storage. 16TB should give me a years free space or so before 6TB hard drives become economically viable.
 
JMcQueen said:
I could actually just buy a msata ssd and use the other four for storage. 16TB should give me a years free space or so before 6TB hard drives become economically viable.
Click to expand...

This is what I have, 1 msata and 4 3Tb on this board. Np with 120 watt HP brick.
 
I think Diverge is confused, JMcQueen asks for how much drives can be powered through this board. This board has a SATA power connector, because this is meant for system integration and a power brick doesn't have SATA power most of the time.

5UnLQsXl.jpg

(bottom-right)

Since this board uses a 19V power brick, it has some of the power supply on the board itself, to convert the 19V into 12V, 5V and 3.3V. This isn't limitless, it depends on the on-board limits. The documentation says:
Board power supplied through SATA power connector is rated at a maximum of:
• 4.5A from 12 V rail (1.5 A each pin)
• 4.5A from 5 V rail (1.5 A each pin)
• 4.5A from 3.3 V rail (1.5A each pin)
Click to expand...

So basically it allows about four drives with about 1A of 12V draw. But even the WD Green drives can peak at 1.75A per drive, so even 3 drives are about 15% over-spec. If you can find harddrives that don't peak over 1.1A, you are set though. Otherwise, you'd need another PSU for the disks.
 
Phuncz said:
So basically it allows about four drives with about 1A of 12V draw. But even the WD Green drives can peak at 1.75A per drive, so even 3 drives are about 15% over-spec. If you can find harddrives that don't peak over 1.1A, you are set though. Otherwise, you'd need another PSU for the disks.
Click to expand...

If the OP uses an HBA that supports staggered spinup like Diverge is, then it's not a problem. Peak usage is always at spinup, read/write usage is usually 25% of peak. As long as the OP sticks with 5400RPM drives and staggered spinup, there's plenty of power for 4 HDDs

That said, I also found a few posts on various forums (including the one above yours) from people using the onboard power with 4 HDDs without using staggered spinup, and they didn't have any problems. It makes sense, the peak load is only for the tiniest fraction of a second when the drive motor starts to spin, and I'd expect the onboard the handle that OK. If you're running some sort of NAS software that supports it's own staggered spinup control, or the drives are configured to never spin down, even better.
 
Yeah that certainly is a solution. But I wouldn't have recommended people cutting up their PCIe slots to fit a HBA controller to connect four disks for the sake of staggered spin-up.

It could be that the specs state maximum continuous and that peak is much higher. I haven't found any documentation on this. I'm sorry if I made it seem impossible, if it is indeed possible, than there is no problem.
 
Yeah, from looking around some more, the peak seems to be much higher. I even found a guy running 6 HDDs off the onboard power, 4 with a 2.5A spinup and 2 with a 2A spinup. That's over 3x the rated spec! :)

It kinda makes sense that even works, as most DC-DC converters can handle peaks way above their rated continuous loads for very, very short periods (we're talking a few hundred usec here), and this falls off quickly as time increases. It should be more than enough for a drive spinup to finish. Having different drive models helps even more, as their spinups won't happen at exactly the same time, so spreading the peak out.

Almost makes me wish I had one of these, just to see how many drives I could connect before they didn't work or something went up in smoke. :) I even dug through my pile of Intel devkits here at work, and found some similar boards, but nothing identical, so I couldn't give it a test.

I might have to look up the specs on these test boards (if I can even find them), and see what they support, then connect a pile of drives.
 
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