At the heart of the P4C800 Deluxe is the Intel 875P chipset. 875P supports the latest 800MHz processors, and is backward-compatible with 400MHz and 533MHz FSB processors. In the same fashion, 875P is also compatible with DDR400, DDR333, and DDR266 memory types, and supports asynchronous memory bus and system bus operation. This means that you can run your 800MHz bus processor with DDR333 memory that you may already have, although it will cost you some performance.
This gives end users lots of flexibility when it comes to configuring their system. If you donít have the money for a complete upgrade now, you can upgrade in steps, say a motherboard and memory upgrade now, saving the processor until prices are more affordable.
4 Banks of Dual DDR goodness
Like Intelís E7205 chipset, 875P employs a dual-channel memory architecture, meaning that peak memory bandwidth is doubled when both memory channels (controllers) are populated with system memory. For increased compatibility, you can install a single memory module, but since youíre only utilizing one channel you will be operating in single-channel mode and thus getting reduced performance. To operate in dual-channel mode, memory must
be installed in pairs, so if you install three memory modules, youíll be operating in single-channel mode.
Serial ATA RAID
Although the P4C800 Deluxe natively supports Serial ATA hard drive technology via the Intel ICH5 chip, ASUS goes one step further by utilizing the Promise PDC20378 controller to support additional ATA/133 or Serial ATA hard drives with RAID support. ASUSí decision to implement the PDC20378 is an interesting one in that Intel offers native RAID support with its ICH5R chip, hence the R in the name. For intense situations where the disk is being used heavily, native support would appear to be the better solution on paper, as the PCI bus that the Promise controller must utilize is limited to just 133MB/sec, in contrast Serial ATA tops out at 150MB/sec. (But keep in mind that even the fastest hard disks wonít come anywhere close to their theoretical peaks.)
FireWire, South Bridge, Promise, and FireWire controllers as well as h/w monitoring
ASUS likely has heaps of PDC20378 controllers in its inventory and thus probably didnít want to be tied to Intel if supply of ICH5R chips dry up, a problem which occurred with Intel in the Pentium III days. Also, the Promise controller supports RAID Level 1, a feature the ICH5R doesnít offer.
3Com and ADI controllers
In another bit of a surprise, ASUS has elected to go with 3Comís 3C940 controller rather than Intelís built-in networking with CSA architecture. With CSA, a dedicated pipe between the Ethernet controller and North Bridge is available, this link offers up to 2Gbps of bandwidth. The 3Com controller utilized by the P4C800 Deluxe must instead use the PCI bus, just like the external Promise controller. Again, those of you in a traditional desktop environment will likely never hit the theoretical maximums, but we can see the benefits of CSA in an office or networking environment. At the very least CSA removes some of the burden off the PCI bus, but with external PCI-based chips for storage, FireWire, and networking, it can certainly be argued that the P4C800 Deluxe is straining the PCI bus to its limits unnecessarily.