2 PSUs with one machine?

[jhayat2]

I can get into all the details if need be, but the bottom line is, my RME PCIe card is (apparently) causing some of my SATA HDDs to not be recognized by the BIOS. There is no real scientific way for me to confirm this, but it seems as tho my 850w PSU is not enough for everything.

Can I have two PSUs for one machine? PSU #1 would feed the MB, which would then power the CPU, cooler, case fans, vid card, and aforementioned audio card. PSU #2 would feed the HDDs. Can a PSU work like this - feed only HDDS w/o otherwise being plugged to the MB?

I have no issue buying a higher wattage PSU, but I guess I am concerned that one still might not do it.

Will two PSUs work?

Thanks in advance.

 

[DSzymborski]

You can, but it's an unwieldy mess.

A better way to start would be to tell us about your PC, including the power supply; you're asking for an answer before telling us most of the question.

 

[XMEN_2012]

Yes, practically it is possible if you power your HDD with separate PSU and rest of the system with other PSU only cache is you need HDD to powered on before booting motherboard or else it will not recognize it.

You can read this guide for better understanding.

 

[jhayat2]

but it's an unwieldy mess

Why, may I ask?

Ok, here's the deal:

New computer build:

i9 7940x
bequiet cooler (250w)
ASUS TUF X299 Mark 1 MB
128 GB (8 modules) DDR4-3200 GSkill TridentZ RAM
6 WD Black SATA HDDs
Basic EVGA GeForce/NVIDIA fanless PCIe vid card (no gaming here)
RME HDSPe PCIe sound card
3 case fans
Corsair 850w PSU (brand new)

I obviously cant know what the BIOS is telling me w/o the vid card (no onboard graphics), so that has to stay in. With the sound card in place, only four HDDs are recognized by the BIOS. Any four; any combo. Remove the sound card, and all six HDDs are recognized. Replace the sound card, and I am back to four HDDs. It would be rather difficult for me to start removing RAM modules, as I would have to remove the cooler first. I can do it if I absolutely have to, but would like to try and avoid it.

So, my thinking here, is that 850 just isn't enough power, hence the thought of me adding another PSU.

Hopefully I have given enough info here

Thanks!

 

[DSzymborski]

I'm not seeing any reason to think that you're anywhere near 850W. Hard drives tend to use around 25W each.

Have you looked in your manual for any PCIE/SATA conflicts? Quite frequently, there are slots that conflict with each other. For example, on my motherboard, if you use a specific NVMe slot, you lose two SATA slots and in the bottom NVMe slot, you lose the third PCIE slot.

Call the hard drives 200W. Be very generous and call the CPU 200W. 50W for the sound card and maybe 20W for the video card. RAM and fans isn't putting you over the top. It's amazingly tough to get even in the same ballpark as 850W without a high-end GPU.

 

[XMEN_2012]

but it's an unwieldy mess

Why, may I ask?

Ok, here's the deal:

New computer build:

i9 7940x
bequiet cooler (250w)
ASUS TUF X299 Mark 1 MB
128 GB (8 modules) DDR4-3200 GSkill TridentZ RAM
6 WD Black SATA HDDs
Basic EVGA GeForce/NVIDIA fanless PCIe vid card (no gaming here)
RME HDSPe PCIe sound card
3 case fans
Corsair 850w PSU (brand new)

I obviously cant know what the BIOS is telling me w/o the vid card (no onboard graphics), so that has to stay in. With the sound card in place, only four HDDs are recognized by the BIOS. Any four; any combo. Remove the sound card, and all six HDDs are recognized. Replace the sound card, and I am back to four HDDs. It would be rather difficult for me to start removing RAM modules, as I would have to remove the cooler first. I can do it if I absolutely have to, but would like to try and avoid it.

So, my thinking here, is that 850 just isn't enough power, hence the thought of me adding another PSU.

Hopefully I have given enough info here

Thanks!

Yes 850 Watt should be more than enough for your usage so as mentioned in below answer you need to check manual for sata conflicts because even on cooler master PSU calculator it is not going beyond 650 watt.

 

[jhayat2]

Have you looked in your manual for any PCIE/SATA conflicts?

AHA!!!!!!!!!!!!!!!!!!!!

Dude - I owe you a beer.

This is not something I thought of. Manual reads:

PCIEX4_2 shares b/w with SATA 5,6,7,8
PCIEX16_3 shares b/w with PCIEX4_1

The sound card was in fact in PCIEX4_2. And when I was checking things out - I was moving SATA cables; tho I meant to, I probably never had HDDs hooked to SATA 5,6 while the sound card was in.

I have moved the sound card to PCIEX4_1, and it, and all six HDDs are recognized.

Thanks to both of you!

 

[XMEN_2012]

Have you looked in your manual for any PCIE/SATA conflicts?

AHA!!!!!!!!!!!!!!!!!!!!

Dude - I owe you a beer.

This is not something I thought of. Manual reads:

PCIEX4_2 shares b/w with SATA 5,6,7,8
PCIEX16_3 shares b/w with PCIEX4_1

The sound card was in fact in PCIEX4_2. And when I was checking things out - I was moving SATA cables; tho I meant to, I probably never had HDDs hooked to SATA 5,6 while the sound card was in.

I have moved the sound card to PCIEX4_1, and it, and all six HDDs are recognized.

Thanks to both of you!

Way to go!!

DSzymborski is power supply king 😍

 

[DSzymborski]

Have you looked in your manual for any PCIE/SATA conflicts?

AHA!!!!!!!!!!!!!!!!!!!!

Dude - I owe you a beer.

This is not something I thought of. Manual reads:

PCIEX4_2 shares b/w with SATA 5,6,7,8
PCIEX16_3 shares b/w with PCIEX4_1

The sound card was in fact in PCIEX4_2. And when I was checking things out - I was moving SATA cables; tho I meant to, I probably never had HDDs hooked to SATA 5,6 while the sound card was in.

I have moved the sound card to PCIEX4_1, and it, and all six HDDs are recognized.

Thanks to both of you!

Always like when solutions are painless and free!

I encounter this from time-to-time as I tend to accumulate an ungodly number of hard drives.