Help! ASRock H67M-ITX + i7 2600K + Prime95 = Throttling???

josephclemente

Limp Gawd
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I just built a machine with an ASRock H67M-ITX motherboard and an i7 2600K CPU, all stuffed in a Lian Li PC-Q11 enclosure. The CPU has a Thermalright AXP-140 cooler installed, with a slim Scythe 120mm fan.

I am running everything at stock speeds, no overclocking. All the CPU/voltage/speed settings in BIOS are at the auto or default settings.

When I run Prime95 Torture Test (In-place large FFTs, 8 threads), every few seconds CPU-Z reports my multiplier drops to x 16.0 (from x 34.0). At the time of the multiplier drop, the hottest core temperature is around 61C.

I thought throttling was supposed to happen once the temperature reaches into the high 90s. I tried searching this issue on Google but could only find information on overclocked systems.

Can anyone else with an ASRock H67M-ITX and an i7 2600K CPU confirm if this is normal stock behavior for this combo?
 
hmm maybe try small FFTs? that test the CPU more than the memory, because i believe large FFTs test the memory more, which might not utilize all the threads at max load. when those cores aren't loaded, that's when the multiplier drops.
 
try turning off the c states and all other items that allow speedstep to work then retest to see if it still drops. i had similar experence with a asus p8p67-m motherboard that would drop multiplier under full load conditions everyone thought it was due to the inadequate power phase of motherboard which is likely was the case.

Jen
 
trottling happens (for Intel CPU) on both TDP (heat - Intel uses "measured" TDP, don't ask me why they chose that) and power draw, as set in the BIOS. There are programs, like Throttlestop, that can go into the BIOS (well, CPU MSR, iirc) and actively reset the BIOS power draw settings to a higher limit. This is more of a big deal on laptops, where the Turbo boost function can be useless crippled by strangely low TDP and power draw settings (hidden) in the BIOS. Most enthusiast boards have the option to disable said monitors.

EDIT: clarifications:

the measured TDP is done by an on die ASIC that measures and calculates the current TDP into an actual number figure, like 80W of power being dissapated.

I should of said, set by the BIOS, not in the BIOS - in this situation. Most BIOS/UEFI only allow disabling the monitors, and not changing the actual numbers (makes sense).
 
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Thanks for the information!

I happen to have a second ASRock H67M-ITX motherboard on hand, so I decided to swap boards just to make sure it wasn't the motherboard. Exact same results.

I'll look into that Throttlestop program and also see what I can do in BIOS.
 
Interesting - the Throttlestop program puts an end to the throttling as soon as it loads, but I didn't even click on the "Turn On" button on the lower right. I wonder what it did.
 
lol.... I don't want to know what unclewebb@nbr put into Throttlestop at this point :p
 
Unfortunately I don't own any modern hardware for development purposes so I'm not 100% sure what your problem was or why ThrottleStop immediately solves it. I think ThrottleStop immediately tries to set the multiplier register to the default value when it starts up for the first time.

The clock modulation and multiplier throttling are more integrated in these new CPUs so what's causing the throttling is still a bit of a mystery until I get some hardware and can do some testing. At least ThrottleStop works to get your CPU back up to full speed.

ThrottleStop 3.00
http://www.techinferno.com/downloads/?did=1
 
If memory serves me correctly, in the ASRock BIOS there is an option to turn off throttling. Not in the mood for a reboot right now to check :D
 
So far I've tried just about every UEFI option on/off. I even upgraded to the newest beta UEFI. Speedstep, core limit, power limits, C-states, etc. There is an option to turn off throttling, but it has no effect.

The only UEFI option that kept the CPU throttling fewer times per minute was to turn off one of the cores. I'd imagine it would eliminate the throttling completely if I turned off two cores.

Until ASRock fixes the UEFI (if ever), ThrottleStop has become my best friend.
 
Looks like a temperature sensor somewhere on the motherboard was telling the CPU to throttle.

I flipped the CPU fan around so it is pulling air out of the heatsink, rather than blowing into it. Now I can run Prime95 all I want without any throttling. CPU temperatures are about the same.
 
Nice to know it's no longer throttling :D


Also, I take back what I said earlier about setting TDP and power draw limits in the BIOS. My P8H67-I Deluxe allows for just that.
 
Bump. Same thing happens on i5 2500k. Only fix i found is ThrotttleStop and make it start minimized with windows.
Bios version 1.3. Everything disabled or manual set in bios, it still throttles.
The throttling happens at over 65 degrees celcius (maybe OP had some bad software that reports it), so this got me thinking abit. The maximum Target CPU temperature is 65, above that, it just throttles.

As for OP's last post, cpu thermal sensor is on the cpu not on the mainboard.
 
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