Overclocking Journey And Final Settings, Continue
It's been said that the P5B has an "FSB hole" from about 350 MHz to 400 MHz, and at 400 MHz the strap causes things to get a little easier for the P5B, so we were still hopeful that we could reach for the stars. We tried FSB speeds of 400 MHz to 420 MHz with no luck at all. We even increased our CPU multiplier from 7 back to its default 9, as using a large difference between the default and set multipliers can actually make it harder for the motherboard to run. Still, no joy. After playing with voltages, loosening memory timings and even trying to jury-rig a fan to the Northbridge, we had to admit a measure of defeat: our e4300 just wasn't going to take us to the upper echelons of overclocking heaven.
We turned our attention back to the highest speed we'd achieved, 3330 MHz at an FSB of 370. Testing quickly revealed that this speed was far from stable, and once again, no amount of memory or voltage tuning would keep it that way. We achieved a measure of success at a FSB speed of 360 MHz but some dropped frames and a couple crashes during testing forced us to slow things up once again.
It seems that with our particular combination of hardware, the 350 MHz bus speed was the best we could do for our e4300 CPU, bringing it to an overclocked speed of 3150 MHz. At this speed the system was even receptive to tighter memory timings of 4-4-4-15 at 750 MHz with a very slight voltage increase to 1.9 volts. The result is good considering that this budget memory is only rated for those timings at 667 MHz.
To round out our overclocking, we used ATItool to increase the speed of our GeForce 8800 GTX, which came at stock speeds of 575 MHz-core and 1800- MHz (effective) memory. We achieved a mild overclock of 35 MHz on the core, which was disappointing, as the resulting core speed is even less than the one found on the factory-overclocked XFX GeForce 8800 GTX (in the marathon's high-end system), which comes with a 630 MHz core. The memory was much more willing to be pushed, however, and we achieved a decent overclock of 220 MHz (effective) on the RAM. Our final 8800 GTX clockspeeds were 610 core/2020 (effective) memory.
So that's our story. On one hand we didn't make it nearly as far as we wanted to; on the other, we got a 75% increase in core speed from a $120 budget CPU. I'm all but sure this overclock will make this sub-$1200 machine competitive with the $3500 high-end system at stock speeds - and perhaps even when it's overclocked a bit.
We're getting ahead of ourselves however. For now, let's see how the budget overclocker's system compares against itself at stock and overclocked speeds.
