i7 8700k 4.8 ghz at 1.2 vd
i7 8700k 4.8 ghz at 1.2 vd
UnknownName :
Is that acceptable?
I’m using an LLC on High with Prime95, it ran smoothly without any BSOD. The processor operated at 95°C and 1.20 Vcore, which is excellent.
Yet, I was also told this speed came with HIGH LLC (Load Line Calibration). Essentially, the LLC adjusts your core voltage when the load increases to counteract voltage drop (or Vdroop).
The steeper the LLC setting (slope), the more the voltage rises.
For instance, at an extremely high LLC value, the chip’s Vcore stays at 1.20V during idle. However, under 100% TDP load in Prime95, it jumps to 1.30~1.35V, matching the high temperature you observed.
Yes, according to the data, we reach 4.8 GHz.
I only used prime95 for 10-15 minutes on small FFTs, which seems sufficient.
It makes sense to put more effort into upgrading the cooler for that CPU.
UnknownName :
Is that acceptable?
I’m using an LLC on High and it operated smoothly without BSOD on Prime95 with a temperature of 95°C.
The clock speed was 4.8 GHz at a 1.20 Vcore, which is excellent.
Nonetheless, you mentioned that this speed was reached together with HIGH LLC (Load Line Calibration).
What the LLC does is, it raises your core voltage when the load increases to offset Vdrop (or Vdroop).
The steeper your LLC setting (slope), the more the voltage will rise.
For instance, at a very high LLC setting, the chip’s Vcore stays at 1.20 V during idle.
But when Prime95 operates under 100% TDP load, the Vcore jumps to
1.30~1.35V, which directly explains the high temperature you’re observing.
Therefore, technically you can achieve 4.8 GHz at 1.20 Vcore.
In practice, however, under load you only reach 4.8 GHz at 1.30~1.35 Vcore.
My advice would be to lower your LLC setting. There are various levels of LLC and each motherboard has its own method for adjusting it. You’ll need to search online for instructions tailored to your specific board (which we haven’t discussed yet).
By the way, 95°C under Prime95 is quite high and shouldn’t be maintained for extended periods on your 8700k.
What version of Prime95 were you using and which specific test did you run?
If not, please ensure you’re using Prime95 version 26.6 and perform a Small FFT test (avoid the Blend test, which gives lower temperatures).
Concerning testing duration, 15 minutes isn’t sufficient to confirm stability, at least in my opinion. I recommend keeping Prime95 running for at least 2 hours or even overnight if you prefer not to stare at your machine for hours.
Some users opt for 10–12 hour sessions, but that’s up to you. A 6-hour session seems reasonable.
Finally, just as everyone has suggested, if you plan to significantly overclock your 8700k, you “MUST” install a better cooler. If you prefer liquid cooling, aim for at least a 240mm liquid cooler for entry-level builds.
Cheers.
Looks like that. Keep an eye on the HWmonitor and CPU-Z data while under load; the vcore might be even higher. cus of the LLC being set to HIGH.