What's the fastest CPU i can put on my motherboard?

[enderino]

My bios is version A01. My slot type is LGA775 and I have a Pentium 4 Hyperthreading 3.0ghz cpu.

 

[outlw6669]

It would help if you shared WHAT motherboard you have...

 

[enderino]

Umm I'm not sure but its on a Dell Dimension 8400.

 

[outlw6669]

Your system has a Dell proprietary Intel 925 based motherboard.
The chipset it self supports only single core P4 CPU's but, due to the proprietary BIOS, it is unlikely that you will be able to change your CPU. Your best option would be to upgrade your motherboard and CPU together.

Info on your specific motherboard
Info on the 925 chipset