Mobo power 8pin to 8+4pin adaptor cables?

Bubo · 6 Apr 2022 at 21:11

I am planning a mobo/cpu overhaul from x99/5820k to z690/12700k, and my Corsair HX1000w psu, the one with the blue writing, only has one 8 pin mobo power cable. Seems modern motherboards either have 8+4 pin or 8+8 power connectors. I gather from some cursory research that with 8+4 mobos at least, you only have to use the extra 4pin if you are extreme overclocking. A)is this true?, and B)could I get round this anyway by using a 8 to 8+4 adaptor cable with this specific psu? Would an adaptor cable risk damaging this psu? I am guessing any kind of adpator hacking to go from 8 to 8+8 would be stretching it a bit? So probably will limit myself to 8+4 motherboards this time around.

I am loathe to replace the psu because this psu has been superb for me other the years, no hints of any coil whine on any gpu I have had, so would be a shame to have to replace it, plus the unnecessary cost of course.

mickyflinn · 6 Apr 2022 at 21:53

Is there another eps cable non modular coming from the Psu?

Hx 1000 have 2 x 8 pin eps I believe, 1 modular and 1 wired.

pastymuncher · 7 Apr 2022 at 09:33

The original HX1000 did indeed have a pair of 4/8 pin EPS leads, one fixed and one modular so you should find the modular one with your spare cables. When did you buy the psu? I have to say though that I wouldn't be happy using a psu that is potentially up to 14 years old (launched in 2008) on a expensive modern pc. There's also the fact that it's only rated for the basic 80+ white label so it's not particularly efficient either. Personally I would be looking at a new quality psu that is gold rated and depending on your GPU you probably don't need 1000w.

Bubo · 7 Apr 2022 at 09:55

mickyflinn said:
Is there another eps cable non modular coming from the Psu?

Hx 1000 have 2 x 8 pin eps I believe, 1 modular and 1 wired.

Ahem, erm, yes. Turns out the cable I currently have plugged into my x99 mobo is the hard wired 8pm 12VEPS cable, and there is a spare 8pin modular 12VEPS port on the psu, with corresponding modular cable in the long since stuffed away cable bag that came with it. Only very slightly embarrassed now. Though Pastymunchers comment on the age of the psu is probably more pertinent now anyway, it is indeed about 10 years old at least. Would be a shame to buy a new psu and find it to be a coil whining monster though. My prospective pc would be a 12700K on a Z690, water cooled with a 3080 with a few ssd's and one hdd. Would not be overclocking the gpu but would try to see what the cpu could do.

mickyflinn · 7 Apr 2022 at 10:05

Bubo said:
Ahem, erm, yes. Turns out the cable I currently have plugged into my x99 mobo is the hard wired 8pm 12VEPS cable, and there is a spare 8pin modular 12VEPS port on the psu, with corresponding modular cable in the long since stuffed away cable bag that came with it. Only very slightly embarrassed now. Though Pastymunchers comment on the age of the psu is probably more pertinent now anyway, it is indeed about 10 years old at least. Would be a shame to buy a new psu and find it to be a coil whining monster though. My prospective pc would be a 12700K on a Z690, water cooled with a 3080 with a few ssd's and one hdd. Would not be overclocking the gpu but would try to see what the cpu could do.

Very true about the age of the Psu maybe sell your old system or keep as a back up.

Would be looking at a new 1000w unit with 10 year warranty for your new build , when you thinking of buying ?

Bubo · 7 Apr 2022 at 11:28

mickyflinn said:
Very true about the age of the Psu maybe sell your old system or keep as a back up.

Would be looking at a new 1000w unit with 10 year warranty for your new build , when you thinking of buying ?

Fairly imminently. I was thinking an 850W would do the job after what Pasty said. Maybe will stick with Corsair. If the efficiency difference between current psu and a modern one is a thing then it would eventually pay for itself what with current leccy prices.

mickyflinn · 7 Apr 2022 at 11:48

Bubo said:
Fairly imminently. I was thinking an 850W would do the job after what Pasty said. Maybe will stick with Corsair. If the efficiency difference between current psu and a modern one is a thing then it would eventually pay for itself what with current leccy prices.

850w should do the job fine but was just slightly overspeccing as 3080 can have power spikes of 500w and also allowing for any overclocks. Plsu are more efficent around 50% utilization and gpu's are using more and more power so gives you headroom.