Is it better to "underclock"?

[killem1x1]

Is it better to underclock the multiplier, to overclock the FSB? ie, would I be better at crunching if I setup my 1.4 machines like this:
a 10 for multiplier and 150 FSB, or 11 multipler, and 133 FSB
I'm just grabbing at numbers right now, If anyone has specific numbers please post them.
Thanks

[TC]

Ideally you want both the processor and the fsb running as high as they will go. You need to experiment to find the limits for both settings, then try to use the multiplier that lets you get as close to that as possible. Suppose you know that your ram craps out at about 150, and you also know the cpu you have is not stable past 1400. Divide 1400 by 150 and see what multiplier is closest to that. In that case you come up with 9.3 which is not an option. You can try to see if 9.5 will work, but most likely in this imaginary scenario you would use 9. You would have your cpu and fsb running as close to their max as possible. In your case if you can run 1500, 10X150 is best.

[Phil]

Originally posted by TC
Ideally you want both the processor and the fsb running as high as they will go. You need to experiment to find the limits for both settings, then try to use the multiplier that lets you get as close to that as possible. Suppose you know that your ram craps out at about 150, and you also know the cpu you have is not stable past 1400. Divide 1400 by 150 and see what multiplier is closest to that. In that case you come up with 9.3 which is not an option. You can try to see if 9.5 will work, but most likely in this imaginary scenario you would use 9. You would have your cpu and fsb running as close to their max as possible. In your case if you can run 1500, 10X150 is best.

TC is right you should go for the best of both, set a low multiplyer and push the fsb until the system is unstable, then ramp up the multiplyer until it will go no higher.

[killem1x1]

Thanks guys! I'm doing that now, and it looks like I can hit 150 on the FSB, but your saying that now I should drop the FSB back, and see how high I can get the multipler....right?

[Phil]

Originally posted by killem1x1
Thanks guys! I'm doing that now, and it looks like I can hit 150 on the FSB, but your saying that now I should drop the FSB back, and see how high I can get the multipler....right?

No drop the multiplyer back and see how high you can get the fsb and then push the multiplyer up

[killem1x1]

When I'm determining my FSB setting, do I want to run the multipler at 9?(BTW this is a 1.4 on an Iwill ddr mobo)

[killem1x1]

The reason I ask is because I'm at 152x9.5 now. Should I keep going, or should I be happy with that and raise the multiplier?

[killem1x1]

Now, I'm at 156 :)

[Phil]

Like I said go for the best fsb you can get, drop the multiplyer down to 8.5 really as you may be able to get an fsb in the 160's and that way you know for sure it's not the cpu. Then when the fsb starts making the system unstable slowly increase the multiplyer until it becomes unstable and then maybe increase the voltage slightly as long as your temps are ok.

[killem1x1]

In effect then, my 165x8.5 will be "faster" than 133x10.5?

[Phil]

Originally posted by killem1x1
In effect then, my 165x8.5 will be "faster" than 133x10.5?

If you could reach 165 then yes as memory bandwidth is usually more in demand than cpu power, quake 3 for instance is faster on a p4 than tbird due to the massive bandwidth of dual channel rdram, but take away rdram or start pushing up the fsb on a ddr system and it looses that advantage.

[killem1x1]

OK I maxxed out at 169 x 8.5, sio from here I just up the multiplier until it won't boot. Right?

[Phil]

Originally posted by killem1x1
OK I maxxed out at 169 x 8.5, sio from here I just up the multiplier until it won't boot. Right?

Until prime95 becomes unstable is better, as the computer may seem stable but could fall over in the prime95 stress test which is about as stressfull as any cpu intensive program gets.

[killem1x1]

Thanks for all of the help. I maxxed out at 168 x 9.5@1.85v
That core voltage is as high as this mobo will allow.
I'm goingto attempt to get it hooked up to the net now, thanks again!

[Phil]

What cooling do you have and what temps do you get?

[killem1x1]

Originally posted by Phil
What cooling do you have and what temps do you get?

Swiftech MC462-A
it's hovering about 123F at idle

[Phil]

Thats pretty high for an idle temp, do you have much case cooling and are you sure it's on right.