Moving on to the XE6800, the engineering sample we had could set the internal CPU multiplier to 13x, meaning that theoretically, the CPU could reach 13x * 266.67 = 3.46GHz. Despite our efforts, we didn't managed to get a stable system at that speed, even after raising the Vcore and Memory voltages.

Next we tried 12x multiplier, which, again didn't make for a stable system with our Asus P5B Deluxe Wi-Fi edition. The problem was that even we had set speedstep off in the BIOS, when the CPU load was high, the motherboard dropped the CPU voltage and therefore dropped performance. For that reason, we used Intel's 975DX motherboard that came with both samples and we got a fairly stable system running at 12x266.67 or 3.2GHz. CPU-Z identified the CPU as X6900, probably Intel will ship such product in upcoming months.

Below are several results after overclocking the XE6800. Note that due to different motherboards used, results aren't entirely "accurate", but they do give a ballpark indication...

Apart from only increasing the FSB, users can also lower the CPU multiplier. For example, with the E6600, from 9x to 8x and then further push the FSB higher, assuming it has proper memory. This again is a case of trial and error to get a stable, working system. We have seen reports of the E6600 reaching 3.6GHz :-)