How can I go higher?

This is my Rig:

P4 2.4C @ 3.12 GHz Costa Rica, FP0 # 3312A071
Thermaltake Spark 7 Cooler
Asus P4P800 (BIOS 1009)
2 x 256 MB Kingston ValueRAM, Winbond Chips 2.5-4-4-8 (VDIMM set at 2.65)
340 Watt Enlight PSU
Aopen GF4 Ti4200
SBLive! Value

Max I can get out of my 2.4C is 3.12 GHz with 260 MHz FSB. RAM is set at 5:4, Proc Volts are at 1.55. System is stable at 3.12 GHz with Prime95. BTW, have HT enabled, running memory in normal mode (no PAT).

Raised Vcore upto 1.675, but can't get post with even 170 MHz FSB. Clocked RAM to 3:2, but doesn't help.

Aiming for 3.3 - 3.4 GHz.

What should I do? Is my chip limiting me?

unfortunately it sounds like yer cpu is maxed. try running 1 stick with loose timings . that way u isolate i component at a time and can test its maximum otherwise its hard to know whats failing.

I'm not convinced it's the CPU. If you can get to 260 at default voltage, but can't POST at 270 at 1.65v, I would say it was something else. Memory perhaps? I'd try upping the voltage on the memory a bit and play with the timings.

more vdimm

relax timings

I've dropped mem speeds by going to 3:2.

At 270 MHs FSB that shoud come to 360 MHz only.

So should RAM be a problem then?

Starngely ppl have reported week 12 Costa Ricas to 3.4 Ghz+