How-To Build An AMD/CrossFire Powerhouse PC
Can we build an AMD machine—any AMD machine—that can compete with an Intel-powered rig?
In the forever war between CPU vendors, AMD and Intel have traded places many times—one leads, then the other. Since the advent of Intel’s Core i7, though, AMD hasn’t been able to touch the performance of Intel’s high end, and Sandy Bridge further increases the gap. But, well, you couldn't buy Sandy Bridge motherboards when I wrote this build-it story in February for the May print issue—something about a bad chipset—and I’d been meaning to build an AMD-powered machine for a while now—with CrossFire, even. Why? Partially because I can, but I also want to witness the performance delta firsthand.
Just for kicks, I’m also going to put some effort—and money—into making this system pretty. I’m not going to add lots of flashy lights (though I thought about it); instead, I’m focusing on the case itself and the wiring inside. The result, hopefully, will be a rig I can be proud of, inside and out.
Ingredients
Case/PSU NZXT Phantom $140
- PSU Silverstone Strider Gold 750W $190
- PSU Cables Silverstone PP05 short-cable kit $25
- Mobo MSI 890FXA-GD70 $200
- CPU AMD Phenom II X6 1090T Black Edition Thuban 3.2GHz $200
- Cooler Cooler Master Hyper 212+ $30
- RAM Corsair CMP4GX3M2A1600C8 4GB kit DDR3/1600 $70
- Optical Drive Plextor PX-B320SA BD-ROM $100
- Hard Drive 2TB Seagate Barracuda XT $170
- Solid-State Drive 256GB Samsung 470 Series $500
- GPU Two Asus EAH6870 DirectCU Radeon HD 6870 in CrossFireX $440
- OS Windows 7 Home Premium 64-bit (OEM) $99
- Misc NZXT individually sleeved cables (CB 24P, CB 8P, CB 43SATA, 2x CB 6V, 2x CB 8V) $54
- Zip ties $2
Total for PC: $2,220
Choosing the Hardware
Advocates of AMD’s Phenom chips cite their low power consumption and high overclocking potential—oh yeah, and you can get a 3.2GHz hexa-core for 200 bucks. Indeed, the cost of the Phenom II X6 1090T that I chose, plus a fancy CrossFireX-enabled MSI 890FXA-GD70 motherboard, was only $400 total. This had the makings of an inexpensive build, until I added two Radeon HD 6870 videocards, a 7,200rpm 2TB Seagate Barracuda XT hard drive, and a $500 256GB Samsung solid-state drive. Why these parts? Thanks to a recent price drop, two 6870s in CrossFireX cost less than a single GTX 580, and they help me maintain the theme of AMD solidarity. I chose the drives with performance in mind, plain and simple.

Silverstone’s PP05 short-cabling kit works with any of its modular PSUs to avoid clutter in smaller cases.
Since a clean-looking, aesthetically pleasing build was also part of the plan, I sprang for NZXT’s white Phantom chassis, which looks gorgeous on the outside, has plenty of fan mounts, and is roomy enough that, even when loaded with two videocards, my build won’t look cramped. To make it look even cleaner, I’m modifying my Silverstone Strider Gold 750W PSU with Silverstone’s short-cabling kit and some of NZXT’s fancy, individually threaded power-cable extenders. Throw in a Blu-ray drive, 4GB of RAM, a copy of Windows 7, and Cooler Master’s famed Hyper 212+ CPU cooler (yes, it works on AM3!) and we’re in business.
1. Install CPU, Cooler, and RAM
AMD CPUs, unlike their Intel counterparts, still have pins on them, so be careful not to bend them when you place the CPU carefully into its socket. Make sure to align the triangle on the upper left corner of the socket with its counterpart on the CPU, then lower the lever that secures the CPU.
Next, remove the motherboard’s built-in cooler retention mechanism by unscrewing the four silver Phillips-head screws, and then remove the black plastic structure and its backplate. Most AMD coolers don’t require this, but our Hyper does. Align the Hyper 212+ backplate with the four mounting holes, then put the mounting pins through the holes and secure with the hex nuts using the hex bit included with the cooler (below). Apply a small amount of thermal paste to the CPU, then follow the Hyper’s instruction manual to secure the heatsink to the mounting pins. Tighten the spring screws until they’re no longer easy to tighten.

At this point you should add the RAM to the two slots closest to the heatsink, then clip the heatsink fan to the RAM side of the heatsink (so it blows through the cooling fins toward the back of the mobo) and plug it into the CPU_FAN header.
2. Prep the Case
Remove both side panels from the case, as well as the top and front fascia. Set them aside for now. The NZXT Phantom comes with a rat-ton of hard drive trays. In fact, there’s a whole extra bay taking up room at the bottom of the case where we could be fiddling with PSU cables. Let’s remove it. Flip the case onto its front so the bottom of the case is visible. Unscrew the four Phillips-head screws at the center of the case’s base (below), then flip the case so the rear of the motherboard tray is visible and remove the six screws you see in the center. Then you can remove that whole hard drive bay.

You should also install the motherboard I/O shield at this point. Be sure to install it from the inside of the case, facing out, and make sure all nine ATX mounting holes in the case have standoffs in them.