The P5W64 WS Professional is definitely a header-turner for the performance computing enthusiast. With its passive heat-pipe thermal solution on the chipset to its 8 total SATA ports and 4 PCI X16 slots, it's clear this board is a top shelf offering from Asus.
Dual Gigabit Ethernet ports, 4 USB, 8-channel surround sound, SPDIF and optical, even an external SATA port -- the P5W64's IO panel is populated with all the right options and then some. The board comes equipped with four standard ICH7R SATA ports (RAID 0,1, 5,10 supported) and an additional three internal and one external SATA port hosted by a Marvell SATA controller (supporting RAID 0,1,10). Also, in addition to Asus' proven chipset heat-pipe design, Asus employed their patented "Stack-Cool 2" technology which adds a metal layer on the underside of the PCB in the CPU socket area, providing significant heat transfer from top side critical components to the back side of the board.
Obviously the major differentiating feature of the P5W64 WS motherboard versus other motherboards based on Intel chipsets currently, is its additional 24 lane, 3-port PCI Express switch that Asus used to bring out additional PCIe connectivity for the chipset. The IDT 89HA0324PS PCI Express switch utilizes a single X8 connection to the 975X Northbridge and then in turn fans-out a pair X8 PCIe connections downstream to the expansion slots. So, in total, this chip takes the already existing 22 lanes within the 975X to a full 30 available for graphics and PCIe expansion.
The four full-length slots on this motherboard can be configured in either an X8,X8,X4,X8 configuration or X16,X0,X4,X0 (slots 1-4 consecutively). So in short, in addition to a standard dual graphics ATI CrossFire setup in the first two slots, you also get an additional X8 enabled full-length slot available for higher function cards like video cards, RAID controllers etc. On a side note, Asus retains two of the available PCI Express lanes for the dual PCI Express Gigabit Ethernet controller that is on this board, thus only the remaining 28 lanes are configured in expansion slots.
Of course you could populate all four slots with graphics cards but one of those cards will have to auto-negotiate down to a X4 connection in the third slot, which is driven by Intel's Southbridge. Regardless, support is there for quad graphics and up to 8 simultaneous independent displays. No word of quad CrossFire yet, sorry. However we did find a much more compelling use of that additional X8 slot (in our not-so-humble opinion) with a new PCI Express-based hardware RAID controller card. We'll cover that configuration and its performance in more detail on the pages ahead.