Overclocking P3 533 in Asus P3V4X

[JonathanB]

I recently got the nerve to overclock my two-year old PC. Its a Pentium 3 533 Katmai in Asus P3V4x mobo. I adjusted the CPU to Manual (Multiplier is locked at x4) and set the FSB to 140 and get a speed of 560. Further pushed FSB to 150 and got a speed of 600. And that's the farthest I can go without adjusting the vcore. And it is fairly stable. Got good airflow in there. One overclocker adjusted his System/SDRAM Freq Ratio to 1/1 (Options are 1/1, 4/3, and Auto) but mine hang on several programs. But it does not when set to Auto or 4/3. Anybody knows this setting?

[Midknyte]

Sounds like your ram can't handle it. 4/3 is the ratio of FSB to RAM speed. that setting was made so if you didn't have pc133 ram, you could set your ram to 100mhz. 133/100 =4/3

so at 150, you are running ram at 112.5mhz. 150mhz is too high for most ram. you would need pretty good quality pc133 ram to do it.

[JonathanB]

The RAM is PC 133, one is 128mb and the other a 64mb. What does the AUTO mean? Do I have to stay in 4/3 setting? Does it ever gain speed from the 150 FSB considering that the RAM speed was reduced to 112.5?

[Midknyte]

Not too sure what the auto does. I'm pretty sure it will lower it back to 4/3, though. what to you mean "gain" speed? if the ram can't handle the 150, then it will go to 112.5 which is the 4/3. there is no in-between. if you had FSB at 133, then the ram should run at 133. check the bios and make sure the ram is detected as pc133. I think that the bios determines the ram speed by looking at the fsb speed. if the fsb is over 133, the ram defaults to 4/3.

you could try one dimm at a time and use the 1/1 ratio. Maybe one dimm is better than the other.

[JonathanB]

I mean if I set my FSB at 133, x4 will give a CPU speed of 533. This is detected by WCPUID. If I set my FSB to 150, x4 will give a CPU speed of 600. At 150, the RAM speed is reduced by 3/4 (112.5) isn't it? Then it is now running at 112.5 instead of the first setting of 133. Is running the CPU at 600 with RAM at 112.5 mhz better than CPU at 533 and RAM at 133?

[Midknyte]

the only way to know which is truly better is to benchmark it. sisoft sandra is pretty standard. you can also test framerates of different games.

[JonathanB]

I'll try Sisoft. I'll also check the RAM speed with WCPUID at 600 4/3 when I get back home.

[JonathanB]

Used Sisoft for the first time. The CPU temp is 54C AGP bus speed 76 and PCI bus speed 38mhz. There are several warnings:
PCI bus is too high; FSB exceeds Chipset rated speed Reduce FSB; AGP bus speed is too high Reduce FSB speed or FSB/AGP; AGP multiplier data rate not optimal. What doI do next, go back?

The RAM speed? I don't see the number 112.gmhz. I can see 150 even in WCPUID.

[Midknyte]

dude, you are overclocking, so expect to see those warnings.

pci bus speed is considered 1x. so if your fsb is 150 (4x), then pci is 37.5 (rounded up is 38). agp speed is 2x pci, so that's 76. your ram speed is 3x, so that's 112.5.

[JonathanB]

Thanks Midknyte for staying with me... Any freeware to measure RAM speed? And, perhaps, I'm done? Is there a 150mhz SDRAM?

[Midknyte]

I don't know of any ram speed check in particular, but try searching on google. it doesn't really matter though. just multiply your bus by .75 and that should be your ram speed.

There used to be some pc150 modules around, but i'm not sure it's worth your time.

Try searching on www.pricewatch.com for pc150 modules

http://www.pricewatch.com/1/33/2625-1.htm

[JonathanB]

I'm just curious if ever there is a PC150 ram, though I don't intend to buy it now. Multiplyng the FSB by .75 if you're set at 4/3 to get 112.5 and x1 if set at 1/1 to get 133mhz. Is this correct? And the PC temp... is this okay at 54C (Sisoft reading)?

[Midknyte]

if you set the ram to 1/1 that means it will run at the same speed as your FSB. so if you're at 150fsb, your running the ram at 150 also. that's probably why your system won't run when using the 1/1 right now. it's just too high for the ram.

[JonathanB]

Thanks....:t :t

[JonathanB]

Just another question. I run a CPU fractal test (the name is Total Test) overnight and it survive the CPU Stability Testing. What concerned me is that the Asus monitor indicates a CPU temp of 78-80C and dropped to 52C when I stopped the test. Also, the -12v sometimes reaches more than -13v and the number blinks meaninig it is below the -12v setpoint. Ideas?:rolleyes:

[Midknyte]

That test is putting a full load on the cpu. you might want to get more fans in the system. just a cpu fan ain't gonna cut it. I usually have at least 1 fan to draw air in and 1 to blow air out, in addition to a cpu fan. heat is the enemy.

dunno what's up with the voltage. maybe you need to replace the power supply. if it's working ok, then i wouldn't worry too much.

[JonathanB]

:t :t

[JonathanB]

Just posting back...
The RAM speed? I don't see the number 112.gmhz
...it's in Sisoft>Memory>Speed>Data Rate is 113mhz. It's very clear now. The speed is the same in AUTO and 4/3.