The higher frequency potential of the Prescott core is yet another appeal of the E0 stepping towards the enthusiasts. Processors of that stepping are expected to reach higher frequencies at overclocking than Prescott-core models of earlier steppings. We built the following system to check this out in practice:
- Intel Pentium 4 570J (3.8GHz) CPU;
- ASUS P5AD2 Premium mainboard (LGA775, i925X Express);
- 1024MB DDR2-667 SDRAM (Corsair XMS2-5300, 2 x 512MB, 4-4-4-12);
- Sapphire RADEON X800 XT graphics card (PCI-Express x16);
- Maxtor MaXLine III 250GB hard disk drive (Serial ATA-150).
To cool our Pentium 4 570J down throughout our overclocking tests we took the most efficient air cooler for LGA processors we had in our test lab, Zalman’s CNPS7700Cu. We didn’t increase the CPU voltage as the Prescott core is practically indifferent to this trick. To overclock the CPU we were raising the FSB frequency above the standard 200MHz. The frequencies of the PCI Express and PCI busses were locked at their defaults (100MHz and 33MHz, respectively).
So we were probing for the maximum frequency and found it at 230MHz FSB, i.e. at a CPU frequency of 4.37GHz. The system booted up at that, but couldn’t pass some of our tests. Our attempt to achieve stability by increasing the CPU voltage was expectedly fruitless. So we had to roll back a couple of steps. As a result, the maximum FSB frequency the system was absolutely stable at was 226MHz. The processor was working at 4.3Ghz at that. Here’s a CPUZ screenshot to confirm our words:
So, overclocking a sample of the new Pentium 4 based on the E0 stepping of the Prescott core, we got very satisfying results. Although the tested Pentium 4 570J is the top-end model in its family, we could give it a 13-percent performance kick and set a new overclockability bar for the Prescott. As you remember, this bar was at about 4GHz for the Prescott core of the previous stepping (D0). The new stepping breaks this record easily.
As the new E0 stepping is making its way into junior processor models, overclockers should see various exciting opportunities ahead. So, if you’re a proponent of the Pentium 4 architecture, we recommend that you consider new processors of that family based on the E0 stepping in the first head.