ASUS A8N32-SLI Deluxe: Why Lower Performance?

Almost any fresh-to-market product has some imperfections which are eventually get corrected by the manufacturer in the new revisions or firmware updates. The A8N320SLI Deluxe mainboard didn’t make an exception. The defect in this mainboard was that the SB to NB Frequency option changed automatically after the BIOS settings were reset or the BIOS was updated. This option adjusts the multiplier of the HyperTransport bus frequency between the chipset’s Bridges and thus directly affects the bus bandwidth.

On all new ASUS A8N32-SLI Deluxe mainboards this option is initially set at the correct value of 5X which yields a resulting frequency of 1000MHz. It turns out, however, that any BIOS update or clearing of the CMOS chip with the appropriate jumper resets this option to 2X and the bus frequency is reduced from 1000 to 400MHz as a consequence (the base HyperTransport frequency is 200MHz). The bus bandwidth is reduced in more than two times which can’t but tell negatively on the mainboard performance.

So we manually set the multiplier at 5X, thus restoring the frequency of the HyperTransport bus between the chipset’s Bridges to its nominal value, and retested the A8N32-SLI Deluxe mainboard in gaming and synthetic tests with a new version of the Nvidia nForce driver. The information that the HyperTransport channels between the CPU and North Bridge are 8 bits wide hasn’t been confirmed, although the appropriate setting of our sample of the A8N32-SLI Deluxe was initially set at “8|8”. The performance of the mainboard grew up considerably after we set it at “16|16”.

So here’s our recommendation to all people who are or will be using an ASUS A8N32-SLI Deluxe mainboard. To avoid the low performance problem, be careful when you update the BIOS or clear the CMOS chip for overclocking or other purposes. When you start your system with this mainboard up for the first time, make sure the K8 to NB LinkWidth and the SB to NB LinkWidth options are both set at 16|16 and that the SB to NB Frequency option is set at 5X. Make this check every time you update the mainboard’s BIOS or reset the CMOS to be sure the performance of your mainboard is at the maximum.

This problem may be solved in upcoming BIOS updates, but the last available update we tried didn’t help. It is possible ASUS will release a new revision of the mainboard without the mentioned defect.