OC i7 8700k multipliers vs voltage

[DavePro305]

I'm new to overclocking and I don't really get the relation between multipliers vs voltage. I'm only on air cooling so I can't push it too much. I tried to put all cores to 5gHz (just to test) and it worked pretty good when 1 or 2 cores where active but after an hour of gaming it crashed. Currently, the 8700k sets its tension depending how much cores are in use : (1:4.7 - 2:4.6 - 3:4.5 - 4-5:4.4 6:4.3). Using that schema, and understanding that the more core is in use, the more temps there is so that's why they lower the tension, I changed the multipliers in the bios that way : (1:5.0 - 2:4.9 - 3:4.8 - 4-5:4.7 6:4.6). I only changed the multipliers and I have no clue how I should adjust the voltage to fit those settings. I let the voltage to AUTO in the bios, is that correct or I should enter something specific?

 

[Eximo]

Well I've not tried overclocking in that manner, never had enough cores for that to matter. I usually target all cores at a fixed speed.

But you should work out the stable core voltage/temperature by benchmarking. Basically you want the computer to crash to tell you it needs more voltage, as long as you aren't exceeding your desired temperature. Under 90C is technically okay, but I like to keep my CPUs at 80C or less under a full load.

Until you know if it crashed from lack of voltage or too high a temperature it is hard to say which way you should go.

I would lean towards more voltage to reach the higher clocks, but you'll have to monitor the temperatures to know.

 

[feelinfroggy777]

You will need to set your voltages. I would start at 1.3 and see if it is stable and watch the temps. For me, I would not want my voltages above 1.35 and average temps under load to be above 80C (average temps, not peak).

You may want to try using XTU to test for stability and measure temperatures. At 1.3 if it is stable to move to 1.29 and keep the loop until it crashes. If it is not stable at 1.3 (probably wont be), then go to 1.31 and test for stability. Work your way up till it is stable, or your average temps under load go above 80C or you reach 1.35.

 

[feelinfroggy777]

Well I've not tried overclocking in that manner, never had enough cores for that to matter. I usually target all cores at a fixed speed.

But you should work out the stable core voltage/temperature by benchmarking. Basically you want the computer to crash to tell you it needs more voltage, as long as you aren't exceeding your desired temperature. Under 90C is technically okay, but I like to keep my CPUs at 80C or less under a full load.

Until you know if it crashed from lack of voltage or too high a temperature it is hard to say which way you should go.

I would lean towards more voltage to reach the higher clocks, but you'll have to monitor the temperatures to know.

I agree, I have never overclocked single cores. This makes me want a 8700k even more just to play around with.

 

[DavePro305]

Thank you for your clear explanation!

 

[feelinfroggy777]

No problem. Just remember, you want your average CPU temps under load to be below 80C and you can’t really go wrong. Cause if your voltage is too high, your temps won’t be below 80C.