Non-Haswell compatible PSU?

C

chx

Gawd
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Jun 21, 2011
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I have an old uATX system with a Seasonic S12II 520W and I am thinking on upgrading it to a C226M WS + E3-1225 v3 + 4x8GB ECC and keep the NT-06e cooler and the GTX 660 GPU. Would this work if I disabled the C6 and C7 states? I have no doubt the 520W PSU can handle a 140W GPU + 84W CPU + assorted riffraff load wise, I am just not sure whether this Haswell thing would cause a problem.

(This then would be Linux, using the IGP, and run Windows in a VM with using vfio to pass the GPU entirely. The choice of motherboard is deliberate, it's one of the few Xeon boards with a digital video output and among those probably the cheapest with an M.2 slot.)
 
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Yes, disable C6/C7 states and don't hibernate as a rule and it will work ok.. If the PSU is really old though, it may be time to replace it anyway. A 500W PSU made by Seasonic that supports it could be had for $40-50
 
Well, it's old but didn't see much use, it's been my Windows gaming machine and I haven't gamed that much. It's five-ish years old. (2012 July)
 
matt is bang on. the psu just wont handle the newer power saving shit.
 
Many older PSUs that utilize the DC-DC design are capable of handling the C6/C7 power states. The S12II doesn't look like it is a DC-DC design though.
 
GotNoRice said:
The PSU that you mentioned doesn't even seem that old, are you sure that it isn't fully Haswell compatible? I'm running a powersupply that is almost 10 years old with my overclocked Haswell-E (5820K) and everything is working great.
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Meeho said:
I've run Haswell on older PSUs without problems.
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What makes a PSU Haswell-compatible is whether or not it can handle low power draws (in the 50 watt range or less) without shutting down. If you have a GPU that consumes fair bit of power at idle, or if you don't let the CPU go into the super low power (essentially almost shut off) C6/C7 states, then you won't experience a problem with old PSUs.

The Toughpower looks like it is a DC-DC design, so it would have less issues with the low power states.
 
I read that this problem only surfaces when putting the computer in sleep. I also read the computer might crash at idle. So... which one it is? I never sleep my desktop...
 
chx said:
I read that this problem only surfaces when putting the computer in sleep. I also read the computer might crash at idle. So... which one it is? I never sleep my desktop...
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The CPU can go into super low power sleep states when put to sleep or when idling. Neither statement is false.
 
Ah so I need to disable the C6/C7 because even on idling it might kick the PSU off. Gotcha.
 
Yep. Doesn't pull enough power, PSU thinks it turned off, so it shuts off, CPU gets very confused, and now you're turned off.
 
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