8700 wont go above 3.5Ghz with turbo on

[Kobrakai]

I've just built a new PC with an i7 8700. I don't plan to overclock so I went for the cheaper non-K version with the understanding that it could still reach 4.6Ghz with turbo mode enabled. But I'm unable to get it to go over 3.5Ghz with prime95.

I did some research and found that if all 6 cores are under full load then it can't reach 4.6Ghz but it should still be able to reach 3.8Ghz. I tried running prime95 on a single core and it got to 4.0Ghz but it's still much lower than I would have expected.

I had some problems with the memory on my motherboard. The computer will not POST if the RAM is installed to either of the first two sockets which I think is caused by a bent CPU pin, so I'm using the last two sockets in single channel. I'm wondering if these two problems may be connected?

 

[Kobrakai]

Quite possibly, one pin could be shorting another pin out if its touching it, I did advise in your other thread that you try and straighten it up.

However, I'm running a Ryzen 2700x and the way the turbo works on that is dependant on heat, so the more stress you put on the cpu, the more heat it generates, the slower it runs, in gaming it often hits turbo speeds of 4.35ghz, if I run prime95 I hits between 3.9ghz to 4ghz, this could be whats happening with yours too, easiest way to find out is run something less stressful, a game etc with an OSD so you can monitor the cpu speed.

I don't think it's heat as I haven't seen it over 50C at full load. It never goes above 3.5Ghz when gaming either.

I would try and bend the pin back but it's so small I can't even tell if it's bent or missing. I'm going to see if I can return the board now that the bank holiday weekend is over.

 

[Kobrakai]

The boost on that cpu is 4.3 when all cores are loaded 4.6 single.

Try manually just setting clocks to 4.6 or turn on mce.

Also what cooler are you using? you might struggle with the stock one.

I'm using a Corsair H60. What is MCE?

 

[Kobrakai]

I have "ASUS MultiCore Enhancement" which is set to Auto, the only other option is Disable.

 

[Kobrakai]

Auto should mean it's on. Maybe try it off see if it makes difference and then try back to auto.

It could be another issue. Are you using XMP for your RAM? If so I would try turning that off and see if it makes a difference.

Also are you 100% sure it's an 8700 in there? Is it showing all 12 threads in windows.

XMP is turned off but I have tried with it on as well.

It's definitely a 8700, it says in the BIOS and in Windows. Windows shows 12 graphs in the task manager if I choose to show logical processors.