Intel i5-2500K on MSI P67-GD65 unable to pass the Prime95 test

Recently my computer started giving problem after overclocking the i5-2500K processor. The overclocking seems to be correct and stable but there is no way the prime95 able to complete its stress test. I could not able to get the final result and even prime 95 could not complete the test. I have even tried the latest BIOS dated 1/2012. Tried clearing out the CMOS but no avail. The Voltage is set to auto or sometimes a fixed 1.175V when clocked at stock. So far I have achieved at best 4Ghz. My hardware includes a MSI P67GD-65 motherboard, G.skill 4GB 1333MHz RAM, Intel 160GB ssd and 640GB HDD. The power supply is corsair 850w.

Did you tried to set the Low setting instead of auto and also verified the Droop in CPU-z? What you have to do is to manually try to set up the RAM to the appropriate values. Also try XMP if your RAM comes is compatible for XMP profile. One thing make sure that you should not run the Prime95 with more memory than is available and if you run so, it would cause your HDD thus thrashing to the page file. If you can able to run the prime95 for few hours with a stable condition then it means that the system will be stable under the regular use. You don’t worry about the error and incomplete result obtained by the prime95. You can also find different application in order to stress test the system as like prime95 does. I don’t want to be waste more time on digging up solution for this since your overclock setting seems perfect in all way. You can start using your system.

If you are using the Intel processor, you have to try the IMO Linpack which will offer a more efficient test on new Intel processors. I only do a 20pass MAX memory with LinX and I didn’t get any BSOD so far with my OCd computer. I am currently using the Intel i7 920 at 4 GHz. There is also another system which is built on 2600K at 4.5 GHz. There also I have got good result. As an alternative you can try the Intel burn test.

As far as I know that the new Intel Sandy Bridge processor can safely overclock up to 4.5GHz on air. Intel had claimed that they have system which was running at 5GHz on air. Actually the new Sandy Bridge are overclock friendly and Intel built that computer just to show this thing to the user. The i5-2500k has an unlocked multiplier which will help you mainly during the process of overclocking.

If your processor name contains "k" on the end, it denotes that the processor have a unlocked multiplier. For example i7-875k / i5-2500k / i7-2600k, etc. The max safe voltage for these processors is 1.38v. and with it you can get at least around 4.5Ghz but just make sure that the operating temps are below the 80 Degree Celsius and you will be fine in all the way.

I assume that your prime95 test might be showing you’re a blue screen of death or "HARDWARE ERROR" or something similar. I don’t know about that yet and you even didn’t mention it in your post. If you are actually getting any error or BSOD, then that error would be very much helpful to understand the cause of the problem and find the solution. If your computer really does not boot once the prime95 is failed you have to reset the CMOS in order to set the BIOS to default settings.

In my case I would really raise the multiplier as high as possible until I find the instability in system and after that up the voltage a little. You should raise the voltage too much at once. Try bit by bit. When you see an insignificant change in clock speed, run prime95 for few hours and see if you can get any error message or not. If you see any, you either need to tune back the clock speed or increase voltage a bit more. Do not ever increase the voltage to a dangerous level. It will damage your processor.

Here I don’t think that you are having problem with the overclock settings and hardware related issues. I think that the problem lies in the version of prime95 which could be incompatible with your system or with other related things.

Did you try the latest version or another version of prime95?

Did you try running memtest, to test the memory?

In my overclocking setup I was getting somewhat random crashes with 1600 MHz 8-8-8 RAM settings. It was actually Stock settings but still the system was unstable. Then I changed it to 8-9-8. Since then system started working perfectly. You should keep in mind that Newer Prime95 are more efficient and intensive.

Which version of OS you have installed?

If it is 64bit OS, then get Prime95 64bit version only. Once installed run the Prime95 and then click on Blend> Custom> enter in Memory Field [Total Ram] and start the test. I have been using the Prime95 and as compared with LinX and Intel Burn test, it is the best and others are not good for all round stability

I have a same processor but installed it on MSI P67 motherboard. It is running at default voltages and 100MHz system bus. Later I have multiplied the multiplier up to 45. Due to this, the system processor started running at 4.5GHz. in actually experience, it was really quicker than the default speed. I then ran a IntelBurnTest to check stability. I used all RAM available and ran it at full load on all core available. But the temps were started going above the 80C. This was the way up to the limit. It reached the highest point within just 5 minutes. But when the system was idle, I notice around 50C only. I them assumed that this temp issues can be solved by replacing the stock cooker with a different one. So it is finally confirmed that with the use of Good cooling system like water cooled process, you can get up to 4.5GHz speed without any problems.

You are having a K CPU, so you can set the multiplier manually. Either you can disable the turbo or leave it as it is. If your clock speed is higher, you don’t get any use from Turbo enabled. You can also enable all the energy savings option till 3.9G/4GHZ and you don’t have to increase the VCore. In my case I have configured the process to +0.05V offset VCore and then increase the default core about 1.25V. With 4.5GHz, you should not enable the C6 power state. It has to be disabled but sometimes it is also depends on which motherboard you use actually. Sometimes the board or BIOS will automatically disables all the power saving options.

One last thing is, whenever you overclock the processor, you have to increase the memory speed accordingly because both should be linked. Make sure that you have a third party cooler rather than the stock one.