Core i7 with GA-EX58-UD3R won't boot anymore after hard-crash

While I was doing stablility testing with Prime9.5 with all 8 threads maxing out. Core Temperatures are closing in 100C. After I got back from a bathroom break, The machine was shut-down. Subsequently attempts to reboot it, it failed to post, the fans aren't spinning and no lights on motherboard were brinking. What's my problem?

I assume that the cpu was overheating and auto shut-down or crashed or whatever. Why didn't that core i7 cpu throttling down feature kick in when overheatting?

Here is my core i7 system:

GIGABYTE GA-EX58-UD3R
Core i7-920 2.66GHz (Oced @ 3.8 GHZ)
Super Talent Chrome Series DDR3-1600 6GB
ARCTIC COOLING Freezer XTREME
Antec EarthWatts 750W
Sapphire ATI Radeon HD4350 512MB
Seagate ST3500418AS 500GB SATA2

Any suggestion to make my system post again?

Thanks!

What are . . . er, were . . . your BIOS settings?

Had you Disabled CPU Thermal Monitor, etc, to "facillitate" overclocking? Had you tinkered with any performance settings?

I suppose you can hope your psu fried, but its likely your mobo and/or cpu.

BCLK=181/Uncore multiplier = x16 (NB = 3077 MHZ)/everthing else is BIOS default (unchanged)

This is 2nd core i7 I built and oc'ed. Never seen this problem before even when temp was over 100c during stress test. Usually when if it crashed, I was able to reboot again.

No, I haven't clear CMOS because I thought it has dual BIOS, why should I? It seems to have a sympton of over-heating circuit of psu. I wonder if any of you have run into this before. I am just hoping that nothing got fried, but it needs time to cool down first.

If you don't change your settings it will happen again. It probably was luck it booted in the first place. i wouldn't expect to get it going again without a cmos clear.

This is the follow up. So the something can be noted.

GA-EX58-UD3R mobo was dead, everything (PSU, core i7, mem) else was fine because I was able to swap parts to verify that. Now I got exact the same mobo replacement and is running fine. Yes, overheating caused the failure of the mobo.

The cpu that fried the mobo was core i7 D0 stepping. Apparently, this core isn't 'good' low temp core compared with my other core i7 C0 stepping.

Idle Load
my D0 49C 100C
my C0 40C 90C

This D0 stepping core can often reach 100C during stress test(Prime95) while the C0 stepping rarely reach over 90C. Temps are measured by Core Temp.

The throttle isn't kicked in when it's over 100C. I even have BIOS warning set 90C and never heard or seen anything happend when Core Temp reports over 90C. The problem is that I really don't know the real temp the cores are, just rough guess range from reading the temps from Core Temp or Real Temp or SpeedFan.

Running those parts that hot is not smart.

Good luck.

ARCTIC COOLING Freezer XTREME is my cooler. I wish it had higher rpm(max=1500)
At default speed @2.66 GHZ, core temp is already at 72C during load. Don't tell me that I didn't seat cpu correctly.

The voltage is bios default. I didn't change it. cpu is oc'd @3.8GHZ. vcore=1.36v during load reported by cpu-z.

100C of core temp scares me too. That's why I am looking for reasons. I don't know whom I should trust: Core Temp, Real Temp, or SpeedFan. I somehow suspect that this particular core i7 D stepping I have messed up the temp readings of Core/Real Temp/SpeedFan. During Prime95 stress test with all 8 threads @ 100% utilization:


idle load
speedFan 35C 85C
Core Temp 50C 100C
Real Temp 50C 100C

In my BIOS, I also have lower CPU Warning Setting to 80C and it never kicks in and never warn me. So it appears BIOS doesn't think CPU temp is over 80C yet. I've tried this cpu with two mobos (same kind) and the same result. So I know it has nothing to do with mobos.

If we can believe any temp reports, it seems the answer has to be (a) your cpu shouldn't be clock that high with (b) that cooler.

Normally, we trust CoreTemp/RealTemp/CPUID Hardware Monitor. Not Speedfan.

What thermal paste are you using man? Lets start back with the basics. No way that should run that hot at stock speeds.

You need to get your stock speed temps down before you OC IMO

Sorry about that
Thought u were using stock intel cooler.

Your AC cooler should be much better than mine, so the reason for the temperatures becomes way less likely to be faulty cooling. Maybe you should try reinstalling the CPU?

Coool122, you are absolutely right about that I suffered an incorrect overclock which I wish I could know this sooner. That's the exact problem with my high core temps.

By default, BIOS has VCORE at auto mode. If you don't overclock at all, the VCORE would never go higher than 1.22v at auto mode.

However, if you ever overclock with vcore at auto mode, VCORE would automatically jump to 1.36V which is very high voltage for any air cooling even a good aftermarket cooler. The temp can reach up to 100C with 8 threads max out.
Core i7 920 has overheating protection circuitry, but this motherboard would die before CPU ever reaches its throttling down temperature level. That was the case for me. I've never ever seen or experienced CPU throttling down. However, some motherboards can withstand the heat while others overheat and die.

So don't use Auto setting for vcore because it's not necessary for mild OCing. CPU can easily be OC'ed up to 3.8 GHZ w/o ever raising its "Normal" voltage which is at 1.22V.

After setting my VCORE=Normal mode, my temperature is much lower than before while still enjoying 40% OC @3.8 GHZ. Idle=40C, Load=80C.

Why did motherboard manufacturers set VCORE=Auto by default? I don't see any benefit of doing this, but RMA'ing dead motherboards.