650W bequiet! PSU question - Max HDDs?

Hello friends, How many internal 14TB-18TB hard drives do you guys think will be safe to put on this PSU?



Whats the specs on your drives?

I guess, a more important question is how his drives are handled. You can assume that if the box cannot stagger drives startups, you need to have around 20W per drive, and if it can stagger you can use 10W per drive and give a 20-50W headroom for startup.

Hey @drhicom & @Jacek

So the idea is to shuck wd easystore/seagate 14-18TB externals and throw them on 8 internal sata ports + 16 on an adaptec 71605 PCie card.

Currently, the system plotting at the moment is taking up ~129W from the wall with just 1 external HDD attached. So in terms of overall headroom there should be plenty to handle ~20+ drives even at startup. Once all the drives are plotted for each individual system it will be machines set aside only to farm.

I have heard of staggering HDDs, but potential drawbacks?

I have 12 HDs on 400W PSU. During the boot process it maxes at around 150-160W, then goes down to a tad over 100W. So, you have plenty of head room.

Disk staggering is done during the BIOS part of the boot process. If you think about it, you basically never can start a couple of drives at exactly the same time, even just to small differences in mechanics. What disk staggering does is basically makes those times a bit longer. As mentioned, during the startup, HD can draw about 20W, but that is just for a second or two. So, basically your BIOS boot will be that much longer (I think). Also, virtually all SAS/SATA controllers are hot swap, so that is another way of looking at staggering - your controller is hot-swapping those drives, to avoid that 20W accumulation. So, that is how it works, nothing to worry about - it is a good thing.

Will you use that system for anything else, or just for farming? 130W for an empty system is kind of high. I would strip it from everything but that adaptec card, and just RDP to it.

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Looking at the specs, I thought it was like an ATX power supply 20 years ago.
Perhaps the 12V line for the HDD looks like only one.
There are 12 SATA + HDD connectors, but it is better not to connect any more HDDs.
I apologize if I’m wrong. :sweat_smile:

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About 130W while plotting and somewhere in the 60s-70s just farming the single external drive. I thought that was pretty good, but maybe I can mess around with the power settings to get the 5700G to consume less once the heavy workload is done.

System is currently configured w 4x1TB SSDs inside. 128GB RAM, 3x140MM stock fans. No dedicated GPU

You have to look at the specs of those drive.

hdd uses both 5V and 12V, for both there should be a maximum Amperage listed.
In general, you will have no problem on the 12V rail, this has plenty of headroom.

So 5V is the one to check out. Most hdd’s use something like max 0,7-0,9A on 5V

20-25 disks should be fine on this PSU. Brief peaks in Amperage during startup is rarely a problem, unless you go way way over.

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I’d recommend be quiet! Dark Power Pro 12

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