Corsair hx620w and 4770k

[atmadden]

Have had the above psu a couple of years without issue. Just upgraded and get random reboots guess this psu is no good not impressed.

[Butuz]

Did you upgrade your graphics cards too?

Butuz

[Agent]

Has it ever booted? it's hard to single out the PSU if you've not done any other troubleshooting.

[Greybeard]

Just an FYI, We are currently validating the HX620 PSU with the Haswell platform, so there is no official word yet at the moment if our HX620 is going to be compatible with Z87. However, in your case, I have a feeling that this is the issue. Have you tried a different PSU in your system and see if you get the same behavior? Have you looked into your RAM and maybe run some test like memtest? and see if it comes out clean from the test.

[atmadden]

I now have a 7950 graphics card and have tested the memory which gives no errors. I have just upgraded the cpu, memory and mobo. It only happens when it is idling or goes to sleep. It will run prime for several hours at 4.3ghz without issue.

[jonnyGURU]

Just go into the BIOS and disable the C6 and C7 sleep states.

It's rebooting because the +12V load is so low in sleep state that the PSU assumes that the motherboard shut off. If "power state after power failure" is set to ON in the BIOS, the PSU immediately turns back on because the board assumes the PSU shutting off is a power failure. This makes it look like the PSU actually rebooted the system.

[kompukare]

I now have a 7950 graphics card and have tested the memory which gives no errors. I have just upgraded the cpu, memory and mobo. It only happens when it is idling or goes to sleep. It will run prime for several hours at 4.3ghz without issue.

Well Haswell has new lower power modes (hence all this stuff about PSU compatibility) but I though all the motherboard manufacturers gave you a BIOS option to disable that state.

Course, you don't mention which motherboard you bought but the BIOS should have an option.

[atmadden]

I have the Asus Z87 K mobo and have disabled the C7 power state and the issue has now gone. At least I know its the PSU at fault.