Compatibility and Naming

Prescott Compatibility

Unfortunately, you can’t simply buy a Pentium 4 based on the Prescott core and plug it into your existing Socket 478 motherboard and expect it to work. There’s a good chance that if you already own an 875P or 865-based motherboard, it isn’t compatible with the latest voltage regulator specification. And if it isn’t, Prescott may not work. Even if it does feature the latest voltage regulator, you may need a new BIOS for proper compliance.

To get a better feel for the breadth of Prescott’s compatibility issue, we tested several motherboards. Three of them – ABIT’s IC7-MAX3, ABIT’s AI7, and Intel’s newest D875PBZ – were able to boot and load Windows XP. The others – ASUS’ P4C800-E, AOpen’s AX4C Max, two of Intel’s D865PERL boards, and an older D875PBZ – would not boot up at all. Although Intel maintains that a simple BIOS update should rectify the problem on most boards, a representative of the company conceded that its older D875PBZ probably couldn’t be resuscitated through a BIOS update.

Because the new core dissipates significantly more power than previous products (at 3.2GHz, its Thermal Design Power is 103W), it creates more heat. Intel’s standard heatsink works fine for cooling the chip, but you should certainly exercise caution before using a Prescott in a small form-factor chassis, even though some manufacturers are claiming that their boxes support Prescott.

Naming

Although AMD’s performance rating scheme is often the target of controversy, it’s at least easy to keep straight. Intel’s naming scheme, on the other hand, is about to get much more complicated. Northwood cores (130nm) bear either no letter designation or a ‘C,’ representing Hyper-Threading support and 800MHz front side bus operation. Meanwhile, Prescott cores (90nm) are either ‘A’ or ‘E.’ The former has no Hyper-Threading support and runs on a 533MHz bus, while the latter has Hyper-Threading and 800MHz operation.