Likely, before anyone can help you, we'll need more info. First off, Your motherboard model and manufacturer would be helpful. Second, to determine whether your particular PII 300 is a Deschutes or Klamath core, we'd need to see the Sspec code from the CPU. The Sspec code is a 5-digit code, that will be printed on the CPU (ex, SL36C). If you could give us those 2 pieces of info, we would be better able to help.
"In the computer industry, there are three kinds of lies;
lies, damn lies, and benchmarks."