Problem O/C-ing P4 2.8/533

I recently got a new CPU, a P4 2.8GHz/533MHz D1 stepping, but I don't seem to be able to get this CPU past anything beyond 2.9GHz. Now I guess this could have several causes:

-My old mobos: Asus P4S333 (known not to reach over 150MHz FSB) and MSI 645 Ultra (which actually should be able to do 166MHz FSB, since it supports a 1/5 divider for PCI/AGP). Although I seem to be able to get a little higher FSB out of the MSI board, its still a <10% O/C which any CPU should easily be able to do (right?).

-Crappy PSU: Im using a 300W AOpen PSU, which always gives me a bit low voltages (+12V is 11.2V, +5V is 4.8V, +3.3V is 3.2V, VCore is at 1.47V). Could add a 2nd (200W) PSU though, to power my hdds/cdroms/fans, but my experience with this is that my voltages on the AOpen PSU won't get any higher. They are stable voltages though, they don't fluctuate, and i think the power usage of the 2.8 P4 should actually be lower than a Celeron 2.0 @ 2.8? (Which would run fine at 140MHz FSB on both boards).

-I lucked out with the CPU, although its a fairly new cpu (pack date 06/10/04, FPO/BATCH tells me its from week 18 2004) so I'd expect just a bit more than a 100MHz increase.

Stuff that isn't a problem:

-Temperature, I'm running it aircooled with a Swiftech MCX4000 and a 80mm TT SmartFan 2, CPU won't reach 50C (running it 24/7 with 100% CPU usage)

-Memory, I'm running my DDR2700 @ 266MHz (1:1) at the moment, so that should leave enough head space for a little overclocking.

So I'm a bit clueless on why I can't O/C this CPU, am I overlooking something?

Try to get new and much better PSU. If you plan to overclock like P4 3GHz, you need (in my opinion) PSU which gives about 400-450W. Well, new mobo & psu might come handy.

In most cases Aopen Power supplies are Fortrons/sparkles. Look for the model number, you should be able to open it and adjust the pots inside.

Zebbo said:

Try to get new and much better PSU. If you plan to overclock like P4 3GHz, you need (in my opinion) PSU which gives about 400-450W. Well, new mobo & psu might come handy.

Click to expand...

Wouldn't 300W + 200W be just as good as a single 400W PSU? Been looking around a bit, but the prices of good 400W+ PSUs seem a bit high, maybe even a waste of money since I have enough PSUs lying around (nothing over 300W though).

Tebore said:

In most cases Aopen Power supplies are Fortrons/sparkles. Look for the model number, you should be able to open it and adjust the pots inside.

Click to expand...

Do you mean you can adjust the voltages? Because I think it could make a big difference if I get my +12V back were it should be (that 4-pin +12V P4 connector is there for a good reason, right? ). I will open up the case later today to see what exact PSU it is, will edit this post then.

Edit: The model number was FSP300-60BT, checked it with Google and it turns out to be a Fortron PSU. Opened up the PSU, but I didn't see much that looked adjustable with merely a screwdriver.

That 300 watt power supply should be enough. Ask Larva or post in the case section on how to adjust the power supply .