ASUS P4P800 supports up to 4GB of dual-channel DDR SDRAM. Since this mainboard is based on i865PE, there is no ECC support (it remains the prerogative of more expensive products on i875P only). With 133MHz FSB the board allows clocking the memory in DDR266 and DDR333 modes (DDR400 SDRAM is not supported in this case). If we speed the FSB up to 200MHz, we will be able to use DDR400 SDRAM also. We should point out that DDR333 memory doesn’t work at the nominal 333MHz with 200MHz FSB. Its actual working frequency in this case is 320MHz for better synchronization. There are 4 DIMM slots onboard located in pairs: two for each memory channel. If you install one DIMM module into any memory slot, the board will work in single-channel (64bit) mode, just like by any i845 based solution. To activate the dual-channel mode (128bit) you should use two or four DIMMs of the same size and internal structure. Note that to make sure you will get dual-channel memory mode, the DIMMs should be installed into slots of the same color. It is not recommended to use three memory modules, as the third module will prevent the activation of dual-channel more and will slow down the overall system performance this way. The picture below shows the proper way to install memory modules on ASUS P4P800 (and on any other mainboard based on i865PE or i875P) to get the maximum performance.

ASUS P4P800 supports AGP 8x graphics interface. Moreover, if we trust the mainboard description, it supports only graphics cards with 1.5V signal voltage. To tell the truth, this is a very strange statement, because AGP 8x requires 0.8V and the graphics cards installed into ASUS P4P800 really do enable AGP 8x mode. However, it is not for nothing that they wrote it: the same manual also claims that ATI RADEON 9500 and 9700 based graphics cards will work correctly with this mainboard only if their part number is PN XXX-XXXXX-30 or higher. However, our testbed was equipped with a graphics card featuring PN XXX-XXXXX-10 part number version, and we didn’t have any problems with it throughout the whole test session. Although, this weird statement makes us a bit concerned about the compatibility of ASUS P4P800 with the contemporary and upcoming graphics cards.

ASUS P4P800 mainboard doesn’t have any additional ATA RAID controllers. That is why the maximum number of disk drives you can connect to it is 6. Four drives can be connected to two ATA/100 channels and two more drives – to SerialATA-150 connectors supported by the chipset South Bridge. Since ASUS used ICH5R South Bridge for its i865PE based solution, the SerialATA drives connected to the board can build a RAID 0 (stripe) array. You can read more about the functioning of RAID arrays connected to ICH5 South Bridge in our MSI 875P Neo Mainboard Review.

Also due to ICH5 South Bridge, ASUS P4P800 boasts 8 USB 2.0 ports. Four of them are located on the rear mainboard panel, and the other four ports are laid out as connectors on the mainboard itself. However, it is very strange that ASUS didn’t include any brackets for the case rear panel with the USB 2.0 ports into the mainboard package. It means that when you buy ASUS P4P800, you will be able to use only 4 USB 2.0 ports. If you want to use more ports, you will have to spend some money on an additional device (or a bracket) with the USB connectors.

I would also like to point out that the considered mainboard can recognize any USB devices, such as USB flash drives, card-readers, ZIP-drives, external hard disk drives and the like, as floppy disk drives. It automatically implies that you can access these devices from DOS or any other operation systems, which do not support these devices directly. Moreover, due to this feature you can start the OS from any drive like that.