You're in luck ! I happen to be running and Abit NF7-S rev 2.0 and am running the RAM faster than the default speed the CPU would normally run it at.
First, let me explain: Your cpu is an XP Athlon XP 2100+. Its default CPU-to-RAM interface (the FSB) speed is 266MHz. Using its default setting the CPU's RAM interface will run the RAM at 266MHz even though the RAM is capable of running at 400MHz or possibly a good bit faster. The RAM is capable of running at 400MHz with no increase of its operating voltage, according to its SPD specs.
So, lets try to run it at or near 400MHz to see if it is stable at that speed. Overclocking is always best done by testing using small increment increases. You will need to run Memtest86 to accurately test its stability. The program comes in an ISO disc image file that can be burned to a CD using Roxio, Nero or the free program CDBurnerXP Pro
. These will make a bootable CD that will automatically run Memtest86 when your BIOS is configured to try to boot from the master optical drive before it tries to boot from the primary hard drive.
Configuring the BIOS for RAM for nondefault RAM speeds: When your system first starts up keep tapping the Delete key until you see the BIOS screen. Go to the 'SoftMenu III Setup' screen. There you sholud see your Athlon 2100 listed. Also in the list you will see an item called 'CPU FSB/DRAM Ratio". This is where you can alter the running speed of the RAM by picking a non-defualt ratio between the CPU FSB speed and that of the RAM. Select this item. Besides the entry 'By SPD' you will see all ratios listed in all combinations of the integers 3, 4, 5 and 6.
About CPU/RAM ratios: What ratio of CPU:RAM you are running now is a 1:1 ratio, which means that since the CPU FSB is running at 233MHz so is the RAM. This ratio is the same as the ratios 3:3, 4:4, 5:5 and 6:6. What you want to do first is select the best ratio that will raise the RAM speed closest to or at 400MHz that does not exceed 400MHz. If you play around with your calculator with the 3,4,5,6 integers you will find the optimal ratio turns out to be 6:4
266MHZ X 6 / 4 = 399MHZ (actually its really 266.667 X 6 / 4 = 400.0MHz)
Since this is the rated speed of the memory you want to try this first. Load up the Memtest86 disk, save the BIOS settings and exit the BIOS. Memtest will automatically boot and run. Let the program run through all the tests for 3 passes. No errors should be listed. Your RAM is rated to run at 400MHz so it better pass Memtest86 ! You should definitely notice a boost in speed when running Windows. If the RAM doesn't pass this test then it is defective and you need to get it replaced.
Having passed the 400MHz test, now is the time to increase the RAM's speed a notch and retest. Find the minimally next higher ratio that gets the speed above 400MHz. I think the next ratio is 5:3 : 266 X 5 / 3 = 433MHz. Save this setting and reboot to Memtest86. Run 3 complete passes.
Unfortunately, the ratios are limited to those using the integers 3-4-5-6, and so the next higher ratio is 6:3 which gives a final RAM frequency of 533MHz, a huge increase over 433MHz. Your RAM may very well not run properly at this speed. In fact, this speed may prevent your system from POSTing so that you will have to reset the BIOS with the little plastic jumper in the mobo located near the battery. Check the motherboard nmanual for its location and method on how to do this.
If your RAM doesn't work right away at any particular speed you can try to raise the voltage applied to the RAMS. This can often get RAM to run faster but may shorten the lifetime of it. The default voltage is 2.6V and I think that it can be set to 2.7 and 2.8V.
Overclocking is a painstaking process and you will find that only so much can be done. Also keep in mind that overclocking causes the motherboard components to generate more heat so that making sure your cace is well ventilated is very important. Raising the voltage supplied to the RAM and other components generates even more heat to exhaust. Thats why many overclockers get a case with the ability to mount multiple case fans.
Most cases have cutouts for a fan in the back as well as in the front. Overclockers also like to choose motherboards that allow very fine increments of adjustment of the CPU and FSB frequencies, often available in 1MHz increments for each.
Edited by WinCrazy, 28 April 2006 - 11:02 AM.