overclocking fails after restart, works fine if entering bios before boot

Lain86

Reputable
Nov 25, 2014
3
0
4,510
So I have "overclocked" my system, I use overclock in the loosest sense as this amounts to fixing the clock speed and turning off EIST. I have an i7 4790k and have fixed the clock speed at 4.2ghz, well within the processors capabilities as it is water cooled (Corsair H100i). Motherboard is a MSI z97 gaming 5.

I have stress tested the setup with intel's extreme tuning utility, over 2 hours the processor settles at 60 degrees Celsius. Unfortunately after reboot the system becomes unstable and crashes normally after about 10 minutes, even if just sat at the desktop. This sends me to the bios automatically on restart. It changes none of the settings and as soon as I save and exit again the system is stable and can handle another 2 hours of stress testing.

Not game breaking but I wonder if this is damaging my machine? obviously I can just go into the bios every time I boot and save the settings but this isn't an ideal solution.
 
Solution
The 1333 is a fail safe reversion the BIOS probably did to ensure it could boot the system. Your DDR3 1600mhz modules may even have a 1333mhz SPD (Serial presence detect) that allows this. Older modules that have this configuration generally need to have the settings and timings set manually, or have the XMP profile configured.

Setting the memory profile to the correct voltage, speed and latency may entirely solve the issue, or there may be other issues, but I'd start there first.

http://en.wikipedia.org/wiki/Serial_presence_detect


How to configure your XMP memory profile:

http://www.anandtech.com/show/7364/memory-scaling-on-haswell/2
Make sure the XMP profile is configured for the correct memory settings in the BIOS. Make sure to increase your CPU line load calibration to a higher setting. Increasing the LLC to max is probably fine although high is likely to be plenty. You might also want to disable the speedstepping and C states.
 

Lain86

Reputable
Nov 25, 2014
3
0
4,510
I will look at the memory settings again. Looking now I have 1333 set on my bios but I have 1600 ram. All of the voltages are set at "auto" really all I want is a stable clock speed. I would like to get it up to 4.4ghz as the processor should be able to handle this. I disabled the speed step but I cant find the C states options, but will look tomorrow when it isn't so late.

thanks for the response, few things to try now.
 
The 1333 is a fail safe reversion the BIOS probably did to ensure it could boot the system. Your DDR3 1600mhz modules may even have a 1333mhz SPD (Serial presence detect) that allows this. Older modules that have this configuration generally need to have the settings and timings set manually, or have the XMP profile configured.

Setting the memory profile to the correct voltage, speed and latency may entirely solve the issue, or there may be other issues, but I'd start there first.

http://en.wikipedia.org/wiki/Serial_presence_detect


How to configure your XMP memory profile:

http://www.anandtech.com/show/7364/memory-scaling-on-haswell/2
 
Solution

Lain86

Reputable
Nov 25, 2014
3
0
4,510
You were right, the memory was reverting to 1333 after a restart for some reason. Now I have activated the XMP profile and it seems to have solved the problem.


Thanks for the articles as well, they were very informative. I am guilty of buying nice ram without having set it up correctly. So fingers crossed there wont be any more problems.

Thanks for the help.