The P35 Express is barely a month old, yet Asus already has a whopping seven different motherboards available based on the chipset. To be fair, many of those boards bear more than just a passing resemblance to one another. Take the P5K and P5K3 Deluxe, for example. The former supports old-school DDR2 memory while the latter is equipped to run the latest and greatest DDR3, but the boards are virtually identical otherwise. We've included both in this round-up, and since they're so similar, we'll be dealing with them at the same time.

Before getting started, we should note that the DDR3-capable P5K3 Deluxe runs about $25 more online than the P5K Deluxe. Apparently, it costs more to purchase a motherboard for DDR3 memory that's already considerably more expensive than DDR2 modules, so don't expect the new memory type to catch on like wildfire.

But let's get back to the P5Ks, which are pictured below. The first picture is of the P5K3 Deluxe, followed by an almost identical P5K Deluxe.

The P5K3 Deluxe

The P5K Deluxe

Despite slightly different DIMM slots and coolers, the P5K and P5K3 are built upon what appears to be the same base board. That's a good thing, because Asus has done a generally good job with the layout. The auxiliary 12V power connector is neatly located along the top edge of both boards where cabling won't crowd the CPU socket, and you get no fewer than seven expansion slots—one more than on the IP35 Pro and P35 Platinum.

Asus has even managed to make the boards look decent in spite of the myriad of multicolored ports, slots, and connectors. All those connectors and onboard peripherals makes things a little crowded, and that creates a few problems around the socket area of each board.

The P5K3 Deluxe's CPU socket

The P5K Deluxe's CPU socket

Both PK5s employ a collection of heatsinks and heatpipes to cool their chipsets and voltage circuitry. The P5K3's cooler is the more elaborate of the two, almost completely encircling the CPU socket. Unfortunately, ringing heatpipes around the socket makes it quite difficult to get at some of the posts that hold LGA775 heatsinks in place, especially for those of us with short, meaty digits.

I can't help but wonder if this extensive heatpipe array is really necessary, especially since the P5K makes do with two fewer pipes. DDR3 memory runs at lower voltages than DDR2, so the P5K3 Deluxe shouldn't need a more elaborate heatpipe array than the P5K. It certainly doesn't look like the P5K is losing $25 worth of copper. And that board's less elaborate chipset cooler actually makes it easier to get at two of the socket's retention posts, allowing for much easier heatsink installation than on the P5K3.

From the socket down, the P5K and P5K3 Deluxe are identical, so we can dispense with two sets of pictures. Here we see the P5K3 Deluxe's low-profile south bridge cooler leaving plenty of clearance for longer expansion cards. Cards like the GeForce 7900 GTX and Radeon X1900 XTX won't obstruct access to any of the six SATA ports, either. However, extremely large cards, such as EVGA's GeForce 8800 GTX ACS³ Edition can block up to four SATA ports.

Speaking of blocked ports, we should note that even a GeForce 7900 GTX installed into the lower PCIe x16 slot can complicate access to the IDE port on the P5K and P5K3. You should still be able to snake the cable under the card, and the bottom two SATA ports are unaffected, but it can be a little tricky to route things neatly.

Clearance issues aside, at least the P5K and P5K3 should make everyone happy on the expansion slot front. The boards feature dual PCIe x16 and x1 slots in addition to three PCI slots, although you'll lose two standard PCI slots to double-wide CrossFire configs.

Over to the left in the picture above, you can see a PCB jutting out perpendicular to the board. This protrusion houses a Realtek RTL8187L Wi-Fi chip that provides the P5K3 and P5K Deluxe with wireless networking capabilities straight out of the box. Wi-Fi seems like a perfect peripheral for motherboard makers looking to differentiate their products, yet only Asus has aggressively pursued onboard wireless networking solutions. Others would do well to follow.

Since Wi-Fi reception probably isn't very good inside your system, the wireless module has a standard antenna jack that pokes out of the port cluster. There, it's joined by a myriad of expansion pots, including coaxial and TOS-Link digital S/PDIF outputs. A PS/2 mouse port is curiously absent from both the P5K and P5K3, though. That probably won't irk most folks—everyone and his mother has at least a USB mouse these days. However, those hoping to use the P5K series with PS/2 KVM switches will have to make do with just a keyboard. That's a reasonable trade-off, I think. The vast majority of users are going to get more utility from two additional USB ports than they would from a PS/2 mouse port. If you must run the P5K series through a KVM switch, it's time to upgrade to one with USB support.

If they really wanted to please everyone, Asus could have included an onboard header for an optional PS/2 mouse port. Instead, they've provided headers for an additional Firewire port and six more USB ports, just to rub it in.

Asus throws a couple of goodies into the box along with the P5K and P5K3, including handy header blocks that make connecting front-panel case wiring much easier when a motherboard is installed in an enclosure. An auxiliary blower that snaps onto the boards' chipset coolers is included, as well, although Asus only suggests it's needed for water-cooled systems that lack sufficient ambient airflow to circulate air around the chipset cooler. Rounding out the bundle is a simple Wi-Fi antenna that seems to do a relatively good job of picking up nearby signals. You may want something more robust if you intend to leech Internet access from your neighbors, though.