Running Arch on an overclocked PC is totally fine provided that the PC is stable at the overclock settings. There are several programs available to you that will help you stress test your system and thereby the overclock levels you are attempting to achieve. The steps of overclocking a PC are beyond the scope of this article, but there is pretty inclusive guide written by graysky on the topic: [Overclocking guide].
Linpack is an excellent way to stress CPUs for stability.AUR
Memtest86+ is a standard memory testing util and is packaged in [extra]
Mprime is an excellent way to stress CPU and memory.AUR
Systest is another piece of software with built in check for system stability.AUR
A very good program for stress testing your memory is [Memtest86+]. It is based on the well-known original memtest86 written by Chris Brady. Memtest86+ is, like the original, released under the terms of the GNU General Public License (GPL). No restrictions for use, private or commercial exist other than the ones mentioned in the GNU GPL.
You may download it from the webhost of memtest86+ [here] either as a bootable CD ISO or as an pre-compiled bootable binary. The later can be called by GRUB with a minor modification to your menu.lst to allow you to boot directly into Memtest86+ without a CD/DVDROM.
Either download and burn the ISO to a CD and boot from it, or follow the instructions in the next section to add an entry to your GRUB boot menu. Either way when you enter Memtest86+, the application begins testing your memory without your intervention. It will run indefinitely until you stop it reporting any errors as it goes. When it has completed a number of iterations without errors or runs for an arbitrary amount of time without errors, you can pretty much call your memory "good" or "stable" at the settings you have chosen for it in your BIOS.
Running Memtest86+ from GRUB's Bootscreen
Either install the package
pacman -S memtest86+) or download the pre-compiled bootable binary from the webhost above and move or copy the .bin file from the archive to
/boot/memtest86+/memtest.bin. Next, edit your
/boot/grub/menu.lst by adding something like the following entry:
title Memtest86+ root (hd0,2) kernel /boot/memtest86+/memtest.bin
You will obviously need to change the device specification (
(hd0,2)) to make sense on your own system. Remember that the
(hdx,y) format takes its inputs starting from 0, not 1; in other words, your first hardrive is
0 and your first partition is also
0. If your root partition resides on the 1st partition of the 1st HDD, then you would use the following line:
/bootpartition, then you may need to omit the preceding '/boot' from the kernel line of the above example. Your kernel line in this scenario could simply be
Stressing CPU and/or Memory
A very good program for CPU and CPU/memory stress testing is [prime95]. There are both x86 and x86_64 version for Linux you can freely use for stress testing purposes under Linux. Prime95 under torture test mode will preform a series of very CPU intensive calculations and compare the values it gets to known good values. The theory is that if your system is sufficiently stable to get the right answers, it should be stable to most anything you will throw at it. Prime95 is pretty much recognized universally as one defacto measure of an overclocked system's stability.
Prime95 for Linux is called mprime and is available in the AUR in [this package].
Running mprime (prime95)
To run prime95, simply open a shell and type "mprime"
When the software loads, simply answer 'N' to the first question to begin the torture testing. The software begins with the torture test, but if you hit Template:Keypress + Template:Keypress you can break out and return to the main prime95 menu shown here:
Main Menu 1. Test/Primenet 2. Test/Worker threads 3. Test/Status 4. Test/Continue 5. Test/Exit 6. Advanced/Test 7. Advanced/Time 8. Advanced/P-1 9. Advanced/ECM 10. Advanced/Manual Communication 11. Advanced/Unreserve Exponent 12. Advanced/Quit Gimps 13. Options/CPU 14. Options/Preferences 15. Options/Torture Test 16. Options/Benchmark 17. Help/About 18. Help/About PrimeNet Server
There are several options for the torture test (menu option 15).
- Small FFTs (option 1) to stress the CPU (option 1)
- In-place large FFTs (option 1) to test the CPU and memory controller
- Blend (option 3) is the default and constitutes a hybrid mode which stresses the CPU and RAM.
Errors will be reported should they occur both to stdout and to
~/results.txt for review later. Many do not consider a system as 'stable' unless it can run the Large FFTs for a 24 hour period.
~/results.txt; note that the two runs from 26-June indicate a hardware failure. In this case, due to insufficient vcore to the CPU:
[Sun Jun 26 20:10:35 2011] FATAL ERROR: Rounding was 0.5, expected less than 0.4 Hardware failure detected, consult stress.txt file. FATAL ERROR: Rounding was 0.5, expected less than 0.4 Hardware failure detected, consult stress.txt file. [Sat Aug 20 10:50:45 2011] Self-test 480K passed! Self-test 480K passed! [Sat Aug 20 11:06:02 2011] Self-test 128K passed! Self-test 128K passed! [Sat Aug 20 11:22:10 2011] Self-test 560K passed! Self-test 560K passed! ...