Overclocking i7 8700K (Best practice for stabilising memory?)

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11 Oct 2009
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Hi Guys,

Got an i7 8700k from here back when they launched which I'm really happy with. I just wanted to ask some overclocking advice re memory stability. My PC is stable on the core at 5ghz (1.295v) - done 4-5+ hours of Prime95, etc. However, achieving 100% memory stability has been more problematic. (I was initially getting errors with MemTest and this was linked to stuttering in games, so i knew i needed to work on memory stability).

I am using the XMP for a G Skill kit of 16gb 3600 DDR4 RAM (CAS 17)

For the memory stability I increased IO and SA voltages to 1.16. When I was initially finding the OC sweetspot this seemed to be it (further incremental increases didnt seem to have any notable improvement on stability for the number of games I've tested- but i'm willing to test this further.)

So I decided to increase the DDR4 voltage from 1.35v to 1.39v and this seems to have fixed the memory stability.

But I was just wondering whether DDR4 voltage increase is the right way to go about this, or should i spend more time tweaking IO and SA?

I'm also interested to know which of these three voltages have the most effect on heat?

Cheers,

Dan
 
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With regards to IO voltage there comes a point where increasing voltage won't have any effect on stability, infact it can actually have the opposite effect.

I assume the ram is rated at 1.35 for the 3600Mhz?

Did you go straight from 1.35 to 1.39 or test at each individual increment?

Unfortunately overclocks aren't guaranteed as you know, a lot of it depends on the IMC of the cpu.

To be honest the Dram voltage is all good, so if you're stable in your usage I'd just leave everything as is. If anything I'd maybe try and reduce IO and SA closer to stock and see if you are stable at your current Dram voltage.
 
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OP
Joined
11 Oct 2009
Posts
23
With regards to IO voltage there comes a point where increasing voltage won't have any effect on stability, infact it can actually have the opposite effect.

I assume the ram is rated at 1.35 for the 3600Mhz?

Did you go straight from 1.35 to 1.39 or test at each individual increment?

Unfortunately overclocks aren't guaranteed as you know, a lot of it depends on the IMC of the cpu.

To be honest the Dram voltage is all good, so if you're stable in your usage I'd just leave everything as is. If anything I'd maybe try and reduce IO and SA closer to stock and see if you are stable at your current Dram voltage.

Thanks very much for your reply Jay. Yes, the RAM is rated at 1.35v and yes I tested the RAM in increments.

That is interesting to note re IO voltage. In the end, I raised SA and IO in increments together because I had spent so long trying to get the memory stable.

I know that at least one of the two voltages definitely helped stability because I was getting stuttering in games before they were both at 1.16v, so perhaps that is due to SA...I will have a play with lowering them both now that the DDR4 voltage is higher-- do you know if they have much affect on temperatures?

Cheers.
 
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