Compatibility Issues

During our tests of the Pentium D 820 processor we revealed a few unexpected issues with the mainboards compatibility.

First of all, I would like to remind you that Pentium D processors require special chipsets, which should not only work with dual-processor configurations, but also be optimized for dual-core processors. If you install a Pentium D processor into a board based on an older chipset, it will simply not start. Luckily, you will not harm the CPU or the mainboard in this case.

The list of chipsets supporting Pentium D CPUs has been revealed for a quite a while now. It includes the new Intel 955X and Intel 945P/G, and NVIDIA nForce4 SLI (Intel Edition). The previous generation chipsets, i925/i915, do not support dual-core processors. However, our tests showed that the situation with Pentium D 820 is somewhat different.

Pentium D 820 doesn’t have any problems working in i955X or i945P/G based mainboards. In fact, this is quite normal, even despite the fact that i945P/G based mainboards do not support the dual-core Pentium Extreme Edition 840. In fact, I assume this is a purely marketing limitation.

The situation with Pentium D 820 and NVIDIA nForce4 SLI (Intel Edition) is much worse. Our tests revealed a few compatibility issues in this combination. When we installed our Pentium D 820 into NVIDIA nForce4 SLI (Intel Edition) based mainboards (and we tested a few most popular models), the system worked pretty strangely. Although the mainboard detects two processor cores and the operating system boots-up successfully, many popular applications either freeze or cause the platform restart. If you disable the second core in the BIOS Setup the problem will go away, but I don’t think you will like the idea of using a dual-core CPU in single-core mode.

NVIDIA’s comments did not shed any light on the issue (for details see this news story). The company representatives we asked about this matter did confirm that Pentium D 820 is incompatible with NVIDIA nForce4 SLIU (Intel Edition), and advised to use faster dual-core solutions, because the chipset was initially developed for computer enthusiasts who do not work with slow CPU models.

So, Pentium D 820 is only compatible with the new Intel chipsets: i955X and i945P/G. By the way, we haven’t yet reviewed the mainstream i945P/G chipsets announced last week, that is why for your reference I would like to offer you a table with the main characteristics of these chipsets compared against other Intel sets of core logic:

Click to enlarge