Athlon XP Clock Settings

Just finished building my first athlon system and was puzzled when I saw the 2500+ running at 1.1 ghz instead of 1.83. What should i set the clock ratio and front side bus settings to?

CPU: 1.83 GHz
Type: XP 2500 Barton Core
Cache: 512K L2, 128K L1, Total 640KB
BUS: 333MHz

i’m guessing the cpu is currently running at 11x100 = 1100. u can leave the multiplier and change the fsb to 166 to get it running at default speed.

You may have a jumper on the MB for 100/166 FSB settings, consult your manual. Otherwise just set it at 11x166 in BIOS.

I have the same setup. It starts up with the FSB defaulted to 100mhz, so just increase it to 166 and it’ll be normal.

You could also try for something a little more aggressive:

Or this:

I get better performance on the benchmarks at lower FSB and higher multiplier. It seems the CPU doesn’t like the higher FSB, and the DDR performs much the same at 185 as it does at 200.

may be u need to upgrade the bios cause i have ASUS A7NX mobo and 3000 XP and the motherboard doesn’t recognize the CPU even if i put it at 166 it will perform as overclocked CPU . but after i upgrade the bios every thing is ok and i got some extra options like 200 FSB instead of 166 max FSB before.:smiley: :smiley: :smiley:

may be u need to upgrade the bios cause i have ASUS A7NX mobo

It’s not whether or not one CAN run at 200FSB on a 333 CPU, but whether it does any good. In my case it does not, the memory actually loses performance above 190. The CPU gains performance from total clock speed, not from higher FSB. Each combination of MB, CPU and DDR is different, so the only way to know is to test. Many folks assume that higher FSB is better, but unless you test you don’t really know. My memory benchmark is the same at 190 and 195, and starts to drop above 195. 185 gives me the best combination of memory performance and CPU stability in stress tests. (My XP-2600 has stress-test instability above 187, regardless of the multiplier).

rdgrimes, I assume that you have a 2500+ Barton like us, right? What kind of memory do you have, and what motherboard is it on, and what voltages are you using?

rdgrimes system specs:

Asus A7N8X-Deluxe
BIOS 1004
XP2600(333) @11.5x200
Vcore 1.750
2 (512MB) sticks of Corsair XMS 3200 in slots 1 and 3 @100%
DDR volts at 2.7

BTW, after seeing Dave’s 3200+ I don’t think I can hold back on getting a pair of Corsair PC3200C2 XMS now. Next week, next week.

XP-2600, Vcore 1.775 (plus .06)
Asus A7N8X-D rev 1.6, 1004 final BIOS
XMS PC3200, 512x2 in dual channel mode, 7-3-3-2, 2.8 VDIMM

PCMark02 scores:
200x11.5 (2300)- Memory 5680, CPU - 6975
195x 11.5 (2243) - Memory 5810 CPU - 6850
190x12 (2280) - Memory - 5780, CPU - 6925
185x 12.5 (2312) - Memory - 5710, CPU - 7000

As you can see, the DDR performs best at 195. The system seems stable at 195, but 3DMark03 crashes at 195 or even 190. At 185x12.5, my 3DMark03 score is right at 5000 with the newest ATI driver, and it’ll loop all day. The DDR is stable with 0 errors (Memtest86) at 200 FSB. So the CPU is the bottleneck at higher FSB here, and is probably what is causing the lower memory benchmarks. But I’m quite pleased with 2312MHz. :bigsmile:

I don’t think I can hold back on getting a pair of Corsair PC3200C2 XMS

The PC3500 is an overclocker’s dream, they’re running that stuff at 220 and up.

Very cool! I’m a bit timid to mess with voltages too much. I do have proper cooling though. I’m satisfied enough at 200 x 11, so I really haven’t tried for more. BTW, I’m using 2 x 256MB Kingston HyperX PC3200 RAM @ 6-2-2-2. Core is at 1.7500V, and VDIMM is 2.7

I’m a bit timid to mess with voltages too much.

get yourself an XP-2100 to play with, they’re dirt cheap and will O/C like crazy.