Problem with LN2- CPU

[cesariuth]

Hi guys,

Last days I've been playing with LN2 with 3 CPUs (980x, 655k and 1100T). I've isolated the mobo with all precautions, but the CPU dies after I finish the session. I mean, when I stop benching the CPU is alright, but then I take it from the mobo, put it in another mobo using air cooling and it won't start.

Any idea of why this is happening?

PS: all CPUs are ES.

thanks!

[K404]

Do the BIOS of the non sub-zero boards support the ES?

Is the PSU of the non sub-zero setup ok?

[cesariuth]

no no I bench alright with LN2 up to shutdown the system but after no run the CPU (air) The CPU is dead.

[El Gappo]

You break down the setup after the session or leave the cpu sitting in water?

[K404]

If you are using the same motherboard as you were with LN2, did you remember to clear the CMOS? I made that mistake.... booted the CPU at LN2 volts + MHz with watercooling

[ScottALot]

You wait for the pot to warm up, right? While you might not notice cosmetic issues after taking it off, the chip can warp if you don't let the pot warm up.

[cesariuth]

You break down the setup after the session or leave the cpu sitting in water?

I broke down the setup only one minute after the end of session.

If you are using the same motherboard as you were with LN2, did you remember to clear the CMOS? I made that mistake.... booted the CPU at LN2 volts + MHz with watercooling

I don't remember, but I think I cleared the CMOS.

You wait for the pot to warm up, right? While you might not notice cosmetic issues after taking it off, the chip can warp if you don't let the pot warm up.

Wow, I didn't know that.

So, what's the correct procedure after shutting down the plaform? ScottALot says I must wait for the pot to warm up, but if I do so I'm afraid that condensation could kill the CPU.

[Hondacity]

vcore? temps?

[K404]

Condensation can't kill a CPU when the rig is powered off

When I finish a session, first thing I do is put everything in a warm oven for ~20 minutes at ~50 celcius, then check for condensation, remove any puddles/ droplets then put it all back in for another 20 (with the oven off)

[[XC] gomeler]

Well, the 990x and the 655k both can die in one session(not so much on the 655k or maybe I had a stupidly resilient one). The 1100T though.. I thought they were more resilient to volts/death than Intel's 32nm options?

Condensation can't kill a CPU when the rig is powered off

When I finish a session, first thing I do is put everything in a warm oven for ~20 minutes at ~50 celcius, then check for condensation, remove any puddles/ droplets then put it all back in for another 20 (with the oven off)

Used to do that. Now I just stuff the entire rig into a styrofoam cooler, wad toilet paper around all the ice and then seal it with tape. Come back the next day and everything is dry and ready to bench again

[G H Z]

Just turn the rig off when you're done, come back next day and tear-down/re-assemble as needed. If you tear the rig down when it's cold you could damage something. Only time I warm the rig up is if I need to re-mount container/keep benching.

[ChanceCoats123]

I've never had issues ending the session at benching temps, pulling the psu, ram and gpu from the mobo. Then I cold pull the pot around -10*C (to avoid condensation). And let the whole lot sit for at least a day.

[NoGuru]

When I am done I will run wPrime until temps get to about -10 or so then I pull the pot off and dry everything with paper towel as much as possible then just wait a day before firing it back up.

[V2-V3]

I slowly warm the pot up to 0C before disassembling the system. As you described I have had one i5 670 die after successful benching and shutdown never did figure on how it happened.

[tiborrr]

The thermal dilatation is the key factor when killing the CPU. You need to gradually heat up the CPU. Your best bet would be to just let the whole system warm up naturally. Normally I underclock the CPU and run Wprime on 1/2 threads. This takes a while but it's almost perfectly safe.