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Question Overclocking of individual cores - i7 7740x


Dec 21, 2017
Hi there,

I'm a user of flight simulators. The one I use is called Prepar3d, and it is a very CPU intensive software. Usually, it will run CPU #0 at 100% for the whole time. The remaining 7 CPU's (threadings) are kept under lower usage (~60-70%).

Because of this requirement, I would like to overclock my i7 7740x. I can make it run at 5 GHz. But, as it is operating around 80°C (sometimes higher) with a watercooler, I would like to keep the other 3 cores at a lower frequency (for example, 4.6 GHz).

But when I start my PC, it will keep the cores synchronized, with the lower frequency - in the case above, 4.6 GHz. The result is:

I tried several options in the BIOS, but I wasn't able to identify what is making these cores to be synchronized. So, how can I overclock my i7 7740x, so the clock of Core #0 is 5 GHz, while the other cores (#1, #2, #3) are kept at a lower frequency (in the case above, 4.6 GHz)?

Best regards


I've played around with individual thread settings before - it is seriously flawed, at least for overclocking.
There are 2 major issues with this for overclockers:
1)As you should know, no 2 threads are the same; how high they can OC and with X vcore, yada-yada... and with OC'ing, one of the goals is to find the lowest stable voltage settings.
You would need to find the stable Vcore for each thread, tedious as it is compared to all core.

2)And this one completely derails it for overclockers: You can't set individual AVX settings for each thread.
Whenever AVX kicks in, whether you enabled an offset or not, all threads will run at the same AVX frequency. And if you don't understand the implications of that...
Ok, say you actually did the individual thread OC, and at some point, AVX triggered - whether in game, browsing, or even running a benchmark.
So now your lower clocked cores are now running the AVX frequency of the highest clocked thread, regardless of an offset or not - then 'bloop!', BSOD!

You have to use auto voltage for individual threads.
As games use all four cores, your goal should be specifying something higher than the stock 4.3 GHz under an all-core loading scenario....; as most 7700K's hit 4.6-4.7 GHz without issue (and the 7740X essentially being a 7700K repackaged for socket 2066 running but 100 MHz higher under all core loadings), that might make a worthy goal for an all- 4 core loading goal. )