This was a novel hypothesis I hadn’t seen it discussed in any of the overclocking resources that I had read.Ĭonfirmation: In the words of Colonel Hans Landa, that’s a bingo! Upping the Vcore from 1.25 V to 1.275 V improved the stability by a large margin. In other words, the CPU Vcore is set high enough for isolated CPU load, but not high enough for combined CPU+GPU load. Hypothesis #3: Loading the GPU is somehow causing the CPU to lose enough power to become unstable. (3) With an open case and all fans set to maximum, the CPU+GPU test failed just as quickly. (2) During isolated CPU/GPU stress testing, CPU/GPU core temps were the same, yet there were no crashes. Refutation: (1) GPU and CPU core temperatures were carefully monitored during stress testing and did not exceed 90☌. Hypothesis #2: The increased heat production is causing the GPU, CPU, or video card VRMs to overheat. Refutation: After replacing the PSU with the Be Quiet! Straight Power E9 580 W (564 W on the 12 V line), the symptoms were exactly the same. The Corsair HX520W supplies 480 watts on the 12V line an overclocked 3570K + HD7850 shouldn’t draw more than 300 W, but there’s also the motherboard, and the PSU is kind of old – who knows, maybe the capacitors have aged? Hypothesis #1: The PSU can’t supply enough power for the combined CPU+GPU load. I repeated the experiment several times and the time to failure was always between 5 and 30 minutes. However, when I ran IntelBurnTest and FurMark simultaneously, I was shocked to see FurMark fail almost immediately. Most overclockers would agree that these results look rock-solid. Prime95 Small FFT (all cores) for 8.5 hours.The system had successfully completed the following stress tests: I had overclocked an i5 3570K to 4.3 GHz at 1.25 Vcore. That’s why the Vcore you arrived at using Prime95 or IBT may be too low to guarantee CPU stability when the GPU is under stress. In other words, to be stable under combined CPU+GPU loads, your CPU may need a higher Vcore than it does for isolated CPU loads. Interestingly, loading the GPU can make your CPU unstable!
That doesn’t guarantee that your system will be stable when both the CPU and the GPU are under load. The problem is that you stress-tested the CPU and GPU separately. Congratulations! Your system is now considered stable.īut then you run Crysis or Battlefield 3 and you get random lockups and reboots. You follow all the standard recommendations that you can find on overclocking forums: you run Prime95 for 12-24 hours, do a few hours of FurMark, and a few hours of IntelBurnTest for good measure. Consider the following situation: You’ve overclocked your CPU, set the core voltage (Vcore) to some reasonable number, and then it’s time for some stress testing to make sure your rig is stable.
0 kommentar(er)
