# FCLK 1GHz on Coffee Lake



## Vario (Nov 14, 2018)

Are there any long term issues with running FCLK (System Agent) at 1GHz instead of default 800 MHz? My understanding is it provides slight performance improvement for discrete videocard performance with no downside and that prior Intel ran at 1GHz but from Sky Lake on, the FCLCK was set to only 800.


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## infrared (Nov 14, 2018)

I've had it set to 1Ghz on my 6700k permanently since buying it, no issues so far.


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## Vario (Nov 15, 2018)

infrared said:


> I've had it set to 1Ghz on my 6700k permanently since buying it, no issues so far.


Did you need any additional VCCSA voltage?


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## jboydgolfer (Nov 15, 2018)

My 8600k has been on 100 since i built it


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## FireFox (Nov 15, 2018)

Vario said:


> from Sky Lake on, the FCLCK was set to only 800.



Some people claim that 800 is the max, mine is and has always been at 1GHz, i don't even look that setting.


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## Woomack (Nov 16, 2018)

1GHz works at low bclk, once you start setting higher bclk then you will see instability or PC won't boot at all. There is some range of working frequency. This is also why there is 800MHz and 400MHz option on overclocking series motherboards. Typical is 800MHz.
On Coffee Lake SA voltage can stay at default at lower memory clock. You will need to set it higher at above 3200 but it depends on the IMC.


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