Be prepared for long hours possibly days waiting and unable to use your pc. Also, be prepared to deal with issues as they might arise. Memory issues, bluescreens etc. Make backups before you begin as a bluescreen may corrupt your startup disk (its unlikely but can happen).
Read up! Go to overclock.net and read guides on stress testing. Whatever tests people run to get an overclock stable is applicable to a stock machine too. Just don't apply their fixes as it may not apply to a stock machine. Testing is the same. If you're not comfortable about it, if its too technical don't do it!
Very important note: stress testing may permanently damage parts as the heat generated can be extreme. With stock coolers and/or bad case ventilation some parts may get too hot and cause permanent damage. Imagine heated air is not ventilated out of your case properly. Each degree the air rises in your case, is fed back to the CPU and causes your CPU to heat up equally. This effect keeps itself going! Stress testing also stresses your PSU, it may fail or even burn out. Its all not very likely to happen but consider yourself warned.
I go through the below on every new pc or when I change parts like CPU, motherboard or memory. Also, I run this every once in a while (6 months to a year) as variables can change.
Document all your current BIOS settings and then reset the BIOS to optimized defaults and make necessary changes like AHCI and boot order. Make sure memory timings are correct (preferably use SPD as it reads the manufacturer's timing tables from the memory itself). At this point, do not overclock or change anything else, you want the most basic, default settings to make sure everything is oke. DO NOT OVERCLOCK! Even if you want to test overclock stability, its meaningless if you don't know if you're machine is stable stock, you need a stable basis for overclocking.
Start with
memtest86+, not to be mistaken with
memtest86, which isn't free and (although the original program) not nearly as good as the + version. Memtest is harmless as far as I'm concerned and can be left over night.
Memtest can be downloaded as a CD image or isntalled to a USB memory stick. Whatever suits you best. Boot from it and memtest+ starts automatically.
Let it finish, a full cycle takes several hours. If you can, let it run for 2 or 3 cycles (I leave it over night). You need to run memtest before anything else because if issues arise during CPU stress testing, resulting in a bluescreen or something, you won't know 100% certain if it could be memory related. Errors will be shown with addresses.
If it finishes fine you're ready for CPU stress testing.
Download the following:
CPU-ZReal TempPrime95 - pick the version for your Windows, v2.66 is the latest. Doesn't require install, just unpack.
Open CPU-Z and RealTemp and let your PC idle for a few minutes and take note the core voltage and frequency in CPU-Z and of the temperatures in Real Temp. If that looks fine, nothing weird continue and open settings in Real Temp and enable log file 5 secs. The log file will be in the program folder where its installed. If that disk doesn't have a lot of free space, you may want to install the program on another drive as 24h of logging can get large
. You can use the log to possibly see what happened in case of a crash/reboot if you weren't there. Also under settings, enable the alarm and use a max temperature you're comfortable with. For me thats 80C but different CPU's have different max temperatures.
If you're on Win7, enable all icons in the notification area. Prime has the nasty habit of minimizing to the notification area when you close it. If your cpu is overheating and you want to close prime, it will still be running! You need to choose Test/Exit or Test/Stop and in the popup, stop all workers.
Also, if you can, make sure all fans are running at maximum for the first time as a safety measure.
Start Prime95 and run the Blend test (leave all default). Watch Real Temp like a hawk! Distance to TJ Max is supposed to be the theoretical maximum your CPU can rise before reaching its critical temperature. I would advise to try and stay at least 10 degrees below that. To give you an idea, my TJ Max is 98C. I stop Prime if it gets over 80C. For day to day use, I want CPU temps to stay below 70C.
Next to watching Real Temp, keep an eye on the Core Voltage in CPU-Z. It should not drop or fluctuate. Even as much as a 100th of a volt can cause instability. <-- read the replies below, on new systems with default settings this should no longer be an issue.Several things can happen when you run Prime:
It runs into infinity without an issue, all workers have a green icon in Prime and your temperatures are fine. To be quite sure your hardware is stable, run it for 12h minimum. To be absolutely sure, run it for at least 24h. There have been several issues with Prime failing at 16-18 hours.
It bluescreens in which case you need to make note of the code, 0x00000101 -or something.
A worker fails, it will get a red icon in Prime. This means your CPU made a calculation error. Not good.
PC hangs, no mouse/keyboard and requires a hard reset.
Runs fine, no faults or crashes but temperatures are out of control. Stop Prime immediately and improve your cooling
.
I can't tell you how to fix crashes/bluescreens/hangs. I'd need to know your settings, hardware and what happened and even then its hard without actually seeing/doing it myself. If you decide to go ahead, make sure you've done your homework, read up!
One more note on Prime: after a few minutes the temperatures will LOOK stable! Don't be fooled! Often it starts to rise again after 30 minutes or an hour! If temps are stable after a few hours, you can leave it alone. For the first few, personally I am always staying around ready to intervene!
And whatever you do, don't panic and pull the plug! If you
must panic, do a reset
. If you pull the plug, all fans stop and your CPU will be left shimmering in its own heat. Reset it and all fans will keep running but CPU load is removed. Of course try to stop Prime manually is preferred though
.
Last but not least, IMHO, if you're not prepared to do the full runs of each test, don't bother doing them at all. There is no point in running memtest for 1 hour and prime for 2 if your intention is to stress test and test stability.
Oh and uh ... don't look at me if things fail/break/burn
.
Good Luck!