Overclocking/Compatibility
Pricing
Besides the 2.8GHz part, today Intel has also released Pentium 4s at clock speeds of 2.5GHz and 2.6GHz (with a 400MHz bus) and a 2.66GHz part (with a 533MHz bus). Official pricing on these chips when purchased from Intel in bulk are $508 for the 2.8GHz CPU, $401 for the 2.66GHz and 2.60GHz chips, and, get this,
$243 for the 2.50GHz and 2.53GHz parts. Pricing on the 2.53GHz chip in particular comes as quite a surprise: officially this was a $637 chip just last week. Today, even Intel's fastest CPU is priced lower than that!
Expect prices on the slower parts to fall in line with these new rates at the beginning of next month. For example, the 2.4GHz Pentium 4 still officially lists for $400 on Intel's website.
In terms of availability, shipments have commenced on all of these processors, unlike the Athlon XP 2600+ that was launched last week. In fact, the 2.8GHz Pentium 4 has already appeared on Price Watch at prices as low as $546 with shipping.
Compatibility
Motherboard compatibility should be seamless, even without a BIOS upgrade. We tested the 2.8GHz Pentium 4 with a handful of motherboards and they were all able to properly recognize the chip's new 1.525V VID. Intel shipped the 2.8GHz part with the same cooling setup they've used for previous processor launches so cooling shouldn't be an issue either. We've heard strong rumors that Intel's upcoming 3GHz chip release will require new motherboards, but we can't get confirmation on this from Intel or motherboard manufacturers themselves. The fact that they haven't denied this rumor however suggests that a motherboard upgrade is certainly likely. We'll have to keep our eyes and ears peeled on this one.
Overclocking
Armed with a variety of motherboards, we were eager to see how high we could overclock our 2.8GHz processor. Since we chose the SiS 648 platform to conduct our performance tests, we naturally turned to one of the first retail SiS 648 motherboards on the market: MSI's 648 MAX. Unfortunately, the 648 MAX only offers voltages up to 1.625V, which didn't leave us with much room for overclocking. In addition, the SiS 648 reference motherboard doesn't support voltage adjustment.
As a result, we were forced to rely on ABIT's 850 solution, which allows voltage adjustments up to 1.725V and bus speed adjustments in 1MHz increments. After lots of trial and error we settled on a final clock speed of 3,024MHz (21x144) at 1.675V. At any clock speed above that, the system wasn't completely stable, regardless of voltage. To obtain that clock frequency, we had to turn down the multiplier on the RDRAM memory so we weren't able to pair the P4 with equally fast memory.