2600k Overclock - Memory Stability Issues

[Maximus_Delta]

Hi,

I have an issues with the 4.5Ghz overclock on my 2600k in that I had to drop the memory down from 1866mhz to 1600mhz to get it to pass Prime95 Large FTTs.

I have tried everything, upping the QPI/Vtt voltage to 1.2v, upping the DRAM voltage to 1.6v, upping the System Agent voltage to 1v etc but after 2-4 hours I get failed workers / threads (rounding errors) in Prime with the memory on XMP Profile 2 (1866mhz). Dropping down to XMP Profile 1 which runs at 1600mhz and its 24 hours stable...

I have retested at stock clocks and the memory is stable on Profile 2 (1866mhz). I am very confused as I thought memory was quite separate from the CPU overclocking now on Sandybridge... any ideas what else I can try to get my memory to run at its rated speed when CPU is overclocked to 4.5Ghz?

Thanks

 

[Maximus_Delta]

Also (thought my sig would show it but not appearing) these are my relevant specs:

CPU: Intel Core i7-2600k @ 4.5Ghz
Motherboard: Gigabyte P67A-UD4-B3, F8 BIOS
RAM: G-Skill Ripjaws-X 8GB (2 x 4GB) DDR3-1866

Also please don't say add more vcore as I had that up to 1.4v and didn't help...

Thanks

 

[amuffin]

Make sure DRAM voltage is at 1.5V! Anything higher can damage the processor! What are your settings for turbo power limit, short, long, etc? I can help, I was able to get my 2600k @4.5ghz with 1.3v!

 

[Maximus_Delta]

Make sure DRAM voltage is at 1.5V! Anything higher can damage the processor! What are your settings for turbo power limit, short, long, etc? I can help, I was able to get my 2600k @4.5ghz with 1.3v!

Turbo is disabled, the multi is just a flat 45x, turbo power settings are no longer applicable.

 

[amuffin]

You need turbo power on! Read this guide: http://www.tomshardware.com/forum/274821-29-sandy-bridge-series-overclocking-cores-guide

 

[Maximus_Delta]

You need turbo power on! Read this guide: http://www.tomshardware.com/forum/274821-29-sandy-bridge-series-overclocking-cores-guide

Thanks but that's not it, my Gigabyte motherboard doesn't even have those settings and I read elsewhere Turbo power has nothing to do with anything when overclocking manually like I am doing. The interesting bit of information I got from that is that some memory modules will not run at their rated speeds at high multiplers. That is the first I've seen of that in a few hours of web reading. I will try putting 1.6v as my DRAM voltage to see if that helps stablize them at 1866mhz.

 

[amuffin]

It does help, how else are you going to be able to draw that amount of power?

 

[azeem40]

I read on OCN that turbo needs to be off. Why would you activate Turbo Boost if you're OCing?

 

[Maximus_Delta]

It does help, how else are you going to be able to draw that amount of power?

Turbo is not enabled, it doesn't care because its just running a flat 4.5Ghz drawing what it needs based on voltage alone. I can see its drawing 110w in HWMonitor. Gigabyte boards don't have this long / short power limit that ASRock do as per that guide. Thanks for the info anway but its not that, this is a memory related issue it seems due to the CPU multipler somehow.

 

[azeem40]

Run memtest86.

 

[Maximus_Delta]

Run memtest86.

Passes memtest at 1866mhz at 4Ghz, also proven Prime stable for 24 hours.

At 1866mhz at 4.5Ghz it fails after a few hours / loops.

Dropping down to 1600mhz at 4.5Ghz and its stable / passes again... but RAM is rated for 1866mhz so I want it to work at that speed..

 

[4Ryan6]

You need turbo power on! Read this guide: http://www.tomshardware.com/forum/274821-29-sandy-bridge-series-overclocking-cores-guide

amuffin my guide does not say to enable turbo, it says to disable it.

 

[4Ryan6]

Hi,

I have an issues with the 4.5Ghz overclock on my 2600k in that I had to drop the memory down from 1866mhz to 1600mhz to get it to pass Prime95 Large FTTs.

I have tried everything, upping the QPI/Vtt voltage to 1.2v, upping the DRAM voltage to 1.6v, upping the System Agent voltage to 1v etc but after 2-4 hours I get failed workers / threads (rounding errors) in Prime with the memory on XMP Profile 2 (1866mhz). Dropping down to XMP Profile 1 which runs at 1600mhz and its 24 hours stable...

I have retested at stock clocks and the memory is stable on Profile 2 (1866mhz). I am very confused as I thought memory was quite separate from the CPU overclocking now on Sandybridge... any ideas what else I can try to get my memory to run at its rated speed when CPU is overclocked to 4.5Ghz?

Thanks

Actually it's really the luck of the draw as to whether your CPU overclocked will run memory past 1333mhz, it is literally a hand shake between the CPU and the Memory modules themselves.

Your memory was never factory tested to be stable under CPU overclocked conditions, it is a serious misconception to think that 1866 memory modules will stay stable overclocked past any clocks the CPU was ever factory tested for.

You can run 1866 but you'll have to relax your timings to do so, it's important you run your modules at the voltage they require exactly, if they are 1.50v modules run them at 1.50V, and set your timings manually.

 

[Maximus_Delta]

Best answer selected by Maximus_Delta.

 

[Maximus_Delta]

Actually it's really the luck of the draw as to whether your CPU overclocked will run memory past 1333mhz, it is literally a hand shake between the CPU and the Memory modules themselves.

Your memory was never factory tested to be stable under CPU overclocked conditions, it is a serious misconception to think that 1866 memory modules will stay stable overclocked past any clocks the CPU was ever factory tested for.

You can run 1866 but you'll have to relax your timings to do so, it's important you run your modules at the voltage they require exactly, if they are 1.50v modules run them at 1.50V, and set your timings manually.

Hi Ryan, thanks, good info that I hadn't come across elsewhere.

After some further testing I confirm what you have stated; extra DRAM voltage didn't help and in my memory settings I have this "Memory Performance" switch and dropping that from "Turbo" to "Standard" still resulted in a failed thread after 8 hours (better but not the 100% stability needed).

It does seem after exploring every permutation of settings that I have no choice but to accept the fact that at the 45x multipler the RAM simply cannot be made to run at its rated 1866mhz.

Thanks

 

[ikameozero]

Also (thought my sig would show it but not appearing) these are my relevant specs:

CPU: Intel Core i7-2600k @ 4.5Ghz
Motherboard: Gigabyte P67A-UD4-B3, F8 BIOS
RAM: G-Skill Ripjaws-X 8GB (2 x 4GB) DDR3-1866

Also please don't say add more vcore as I had that up to 1.4v and didn't help...

Thanks

you can save youself literally 0.5 volts u can get your cpu to 4900mhz on 1.35 turn turbo on and turn hyper threading off as it does nothing for games anyway the difference between hyper threading on and off for games is literally 1 fps but it gives alot less heat to cpu when hyper threading is off saving u 0.5 volts