Prime95 instant fail
Prime95 instant fail
For some reason, Prime95 Small FFT triggers my CPU to hit 96 C and shut down immediately, regardless of clock speed. Details: The chassis is the Phanteks Enthoo Pro with two AF140 Quiet Editions front-mounted. The PSU is a Corsair AX760. The motherboard is an Asus Maximus VII Formula. The CPU is an Intel Core I5-4690k. The cooler is a Corsair Hydro Series H100i GTX in performance mode, with fans swapped for Noctua Industrial F-12 PPC 2000s in push configuration. This setup maintains my i5-4690K at a maximum of 62 C at 4.5 GHz during long sessions of CPU-heavy games such as GTA V and Battlefield 4. When I run Prime95, everyone recommends using Small FFT, and it consistently reaches the highest temperature quickly, failing whether on stock clocks or at 4.5 GHz. The thermal paste was replaced with MassCool G751 Shin Etsu, and the results are similar. Temperatures actually dropped by about a degree in BF4 and GTA V to around 61 C with the same room temperature. Since my 290X isn’t even running well in Prime95, it should be even cooler shouldn’t it? What’s going on?
Please ensure you are using Prime95 version 26.6, as newer versions might affect compatibility. I'm here to clarify any confusion regarding your GPU. Could you provide more details?
I was thinking about the GPU and realized it wouldn't make sense for GTA to have lower temperatures since it uses up my CPU and my overclocked 290X, which generates heat in the case. My cooler is set up with an exhaust fan at the top, so any GPU heat would affect the temperature slightly. However, Prime95 doesn't use the GPU, so I thought the temperatures would be better, not cause immediate failure.
GPUEnthusiast:
I thought about it this way. The idea that GTA wouldn't heat up much because it uses my CPU and my overclocked 290X was a bit confusing. Since my cooler is set up to push air out at the top of the case, any extra heat from the GPU should still show up. But Prime95 doesn't rely on the GPU, so I expected temperatures to be better, not worse. Actually, it's more about the stress test over a game rather than noticeable changes.
I doubt a CPU with solid 240 AIO cooling in Performance mode, using stock speeds, would instantly reach 90°C+ or crash Prime95. Not even with the latest, most aggressive version. My own setup includes two 360-second cooling cycles for both CPU and GPU, and it doesn’t even approach a temperature spike on my CPU when overclocked, even with the GPU at maximum heat.
Try using ASUS RealBench (may need to download from MajorGeeks, as it was too slow on the ROG site) to check the actual temperatures. The stress test should cover CPU, GPU, and RAM (make sure all RAM is used), making it a thorough test. It’s not as intense as Prime95.
Thanks for your responses. Asus RealBench performs well and closely resembles the Blend test in Prime95. Sergeant Sneaky is correct, though—I'm not sure what it does, but I upgraded to version 26.6 and it resolved the issue. I reached 80 C at 4.5 GHz after nearly three hours of stressing with Small FFT. However, I believe Prime95 remains a worse-case scenario that can't be achieved in gaming, so I should be cautious. AIDA64 appears to be more forgiving.
The only issue I have with RealBench is that my EVGA GTX 980 Ti Hydro Copper automatically lowers the memory speed in stress test mode. It also does this during video tests in benchmark mode, regardless of clock speed or overclock level. This behavior occurs at normal speeds and when overclocked, reducing the speed from 7000 to 6600. This is unique to this software and not seen with other programs.