Overclocking 8700k VCCIO and system agent voltage

Disclaimer: This is my first post in the forum.

I'm running a 8700k OCd to 4.8GHz @ 1.24 voltage for a while now with an ASUS rog stric z370-f Motherboard.
I have a pair of gskill Trident Z 8gig sticks. The rams run at 2133 MHz at stock. but i have enabled the XMP profile which sets the speed at 3000 and the DRAM voltage to 1.35.

Now upto this point all seems normal.
But recently i got into more details about how to get better stability after oc and came across VCCIO and SA voltage (which i ignored previously as most oc guides dont tell us to mess with these)
These voltages were set to Auto in the mobo.
I noticed that at stock the voltages were: VCCIO: 0.968 and VCCSA: 1.072
after running the xmp profile : VCCIO: 1.232 and VCCSA: 1.232

This seems like a really big jump and i have read in forums that high vccio/sa can lead to the processors integrated memory controller to faster degradation.

now my question is should i manually try to dial down the voltages? What kind of values should i aim for?

You can test and see if your setup will run stable with less VCCIO and VCCSA.

A 3000MHz speed for an Intel Coffee Lake IMC is pretty standard.

I' d test with VCCIO at ~1.115v/1.120v and VCCSA at ~1.150v.

If not stable then tweak the voltages upwards towards the previous auto settings.

Edit: Welcome to the Forums!

I' d test with VCCIO at ~1.115v/1.120v and VCCSA at ~1.150v.



What kind of tests would you recommend for this purpose?

I have lowered the vccio and vccsa gradually upto 1.15 and ran 2 passes of Memtest (all available test),multiple passes of cinebench and at least one hour of Asus Realbench in between each decrement.
No crashes during this testing process. But i usually leave my pc on overnight for downloading and seeding purpose and the system has been crashing while at idle. Dump file shows error in "ntoskrnl.exe" which i looked up and is associated with memory.

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PolRoger said:

Edit: Welcome to the Forums!

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Thank you

If you see any stability issues then just set higher voltage and from time to time, when you see that all is fine, start to lower it a bit.
If you don't have anything really important on this PC then just use it as it's the best test. Stability tests are not always showing problems with too low IO/SA. You can try AIDA64 stability test with enabled memory and cache tests (only these 2) to load memory controller and memory in the same time. If voltages are too low then it should show it but sometimes it takes time. Usually 2h is more than enough.

Woomack said:

If you see any stability issues then just set higher voltage and from time to time, when you see that all is fine, start to lower it a bit.
If you don't have anything really important on this PC then just use it as it's the best test. Stability tests are not always showing problems with too low IO/SA..

Click to expand...

That's basically what i'm doing. the downside is how long it will take to settle down :v

Woomack said:

You can try AIDA64 stability test with enabled memory and cache tests (only these 2) to load memory controller and memory in the same time.

Click to expand...

Okay i'll give it a shot tonight.

3000 MHz on this platform shouldn't need more than stock quite honestly.

I would try the XMP profile then manually set SA/IO voltage at stock values like these other gents said, then tweak it up.