Prime95 fatal error

[nicktay2605]

I've been having some issues with my OC lately. I'm running a 6700k on a Maximus Hero VIII Z170 motherboard and 16GB of Corsair Vengeance LPX 3000Mhz ram (the CPU and mobo were purchased as part of the 8pack bundle on Boxing Day). I've got the CPU overclocked to 4.5Ghz with vcore set to 1.35v and memory set at the recommended voltage of 1.35v. I've run Prime95 at 1.35v and 1.36v vcore but both times one of the workers reports a fatal error: rounding was 0.5, expected less than 0.4. I've got the CPUVCCIO voltage at 1.15000 and the CPU system agent voltage at 1.25000. Max temp the CPU reaches in Prime95 is 78 degrees c, and it's liquid cooled so I don't think overheating is the issue. Also, I've tried reseating the CPU and reapplying thermal paste.

I'm running the standard xmp profile in the bios with the timings that Corsair recommend on their website (15-17-17-35) and ran memtest64 for an hour and that reported no errors. After a quick read around the internet on the error message it sounds like it might be a ram timing or voltage problem, is it safe to bump the ram voltage to 1.4v or is there something else that's causing the issue?

 

[Cold_And_Miserable]

Set the system to stock and enable the XMP profile.
Try IBT at maximum RAM usage for 10 to 20 runs. Then try testing using Prime95 with maximum RAM usage for 24 hours. If it passes it's highly improbable the RAM is bad.

 

[nicktay2605]

Yeah that's what I ended up doing. I went back to stock, enabled XMP and ran IBT and then Prime95 and didn't get any errors. So after all that I figured it must have been something to do with the overclock causing it to be unstable. I think I might have just got unlucky and got a poor 6700k chip, some people only report needing 1.32v at 4.5Ghz but mine seems to need 1.375v. Since increasing the vcore to that number and running Prime95 for a few hours I haven't had any issues. I also played Ghost Recon Wildlands last night for four hours without a crash, so at the moment it looks like it's okay.