bios overclocking



I was just given a 1900xp w\xtx kt400anb there any adjustments i can do to make it a little faster without having to unlock the chip?my fsb is 133 i have two sticks of 512 2700ddr.could i raise the fsb to 333 or do i have to keep it matching the chip at 266.could some one explain how too .thankyou


133 x 2 = 266... simple.
Now, you can raise it gradually. More at first, and as you progress you benchmark it (benchmarks are CPU-intense... so that's good) and check for stability issues.
At 166/167 MHz you're at 333 (roughly). It might not seem like a very big step, but it is, so go slowly. Other things might cause conflicts as well.

If you get stability issues (or heat, that's a big concern) you should downclock it and find a "safe spot". If it's stability alone and not heat at all, you can try increasing the core voltage just a tad. It will make the thing hotter, but should make it more stable as long as you have temperature on your side. ;>
It would help to know what Motherboard you have and which BIOS you are using.

Overclocking is not easy - unless youve been around PC's for a while. You have to keep an eye on CPU temperatures to make sure you arent going to fry anything and some motherboards simply do not overclock well at all.

But there should be a setting in your BIOS which has a value like 133, this is your FSB speed and this is what you should raise. This is multiplied by your multipliers funnily enough and these can either be set on your Motherboard by Dip Switches (little switches or Jumpers if your really unlucky) or in your BIOS. If for example your multiplier was set to 10, then your CPU would run at 10 x 133 or 1330 Mhz.

So you COULD up your Multiplier to 11 for example, so then your chip would run at 11 x 133 or 1462 Mhz, but this is a pretty big jump and would cause the CPU to pump out a lot more heat and it might not even boot. Which is why most boards have the FSB adjustment (133 above). This allows you to nudge up the speed of the CPU and the speed at which data is passed around the motherboard in small steps of 10 or 11mhz if we take the examples above.

So if you changed your FSB to 134 and your multiplier was 10 insead of it running at 1330 Mhz it would run at 1340Mhz.

Be Warned though - IF you try this, unless you know how to reset your BIOS you could end up without a PC. So find this out first before you do anything, or one day - you will push it too far and wont be able to boot.

Have a look at the forums at for more on overclocking. There are a LOT of hardcore O/C's there but also a lot of people like you just starting out, you could learn a lot there just from reading posts.

Good Luck.


i have a xtx kt400anb mb and the mb does have jumpers for the fsb.there are three settings for them they are 200 266 333 i set it to 266 because i have a 1900xp cpu should i raise it to 333? the bios is pheniox award i also have DDR2700.thanx for all your help