Build It: Radeon HD 7990 PC

Maximum PC Staff

A dual R9 290X card isn't here yet, but the 7990 is the next best thing

The ongoing war between Nvidia and AMD for supremacy over the PC gaming landscape has been like the Hatfields and the McCoys of enthusiast computing: long, bitter, and deeply entrenched. Contrary to rumors, AMD hasn't revealed a dual R9 290/290X card yet, but the Radeon HD 7990 is the next best thing, combining two HD 7970 GPUs onto one card. It didn't come out until spring 2013, though, which was long after Nvidia's own dual-GPU behemoth, the GeForce GTX 690, had dug in its heels. And it wasn't until mid-summer that AMD began to address the stuttering issues that marred its multi-GPU setups. With AMD's R9 series arriving late last year, this crown jewel didn’t really have much time to shine. Today, we'll try and change that, pitting this Cadillac of a card against nothing less than Battlefield 4, with everything maxed out and running at 1920x1080. With the previous Battlefield regularly favoring Nvidia cards, this might seems like enemy territory. But this time, AMD is working closely with the developer to make sure nothing goes awry.

Note: This article was originally featured in the Holiday 2013 issue of the magazine .

Gathering the Troops

We're not working with a tight budget this time, so our roughly $750 video card will have some appropriately fancy company. With two 8-pin power connections, the 7990 draws a lot of juice, so that's our first consideration. We went with an 800-watt Cooler Master Silent Pro Gold. As its name indicates, it's a "gold"-rated PSU, so it will work efficiently, and it has some other nice features that we'll get into later. We also wanted a nice motherboard and CPU that could handle all the bandwidth that a dual-GPU card needs—that led us to the Asus X79 Deluxe and a Core i7-4960X. This is the LGA2011 platform, which gives us up to 40 PCI Express lanes, while LGA1150 boasts just 16 lanes. Since LGA2011 uses quad-band memory architecture, we'll be using four sticks of RAM. That’s not critical for gaming, but the extra bandwidth is great for video encoding. For storage, we have a speedy 240GB SanDisk Extreme II SSD to boot with and run games from, and a 3TB Seagate Barracuda for media storage.

Our favorite item, though, has to be the case in which everything gets crammed. That would be the Silverstone FT04 mid-tower. It's not the easiest case we've ever worked with, but the end result is pretty cool, in more ways than one. You've probably noticed that the picture on the opposite page appears to be reversed. That's not an optical illusion. The inside of the case was designed on Opposite Day, and that has some neat side effects that we'll dig into soon.


Case Silverstone FT04


PSU Cooler Master Silent Pro Gold 800W $160
Mobo Asus X79 Deluxe
CPU Intel Core i7-4960X
$1,000 (street)
Cooler Phanteks TC14PE
$80 (street)
GPU AMD Radeon HD 7990 $550 (street)
RAM 4x 4GB Corsair Vengeance LP $150 (street)
Hard Drive 240GB SanDisk Extreme II $225 (street)
SSD 3TB Seagate Barracuda $135 (street)
Fans Samsung SH-S223 $15 (street)
OS Windows 8 64-bit OEM $90 (street)
Total $2,985

1.  The Guest of Honor

The HD 7990 is about 12 inches long, so it's not for the faint-hearted builder. Our case officially has 13.3 inches of room, so it'll work. We wanted to use the case's bundled VGA bracket, which prevents the card from sagging, but it obstructed our jumbo CPU cooler. Fortunately, the HD 7990 has a metal backplate to keep it from bending, so the bracket’s not critical. (Water-cooling the CPU would allow use of the bracket). The card needs two 8-pin cables, which can be challenging to route in a traditional case layout, but here the power supply is installed right above the card, in the top of the case, so the cables don't need to do anything complicated to supply juice.

2. Power to the Tower

The top of the case is no longer a common location for a power supply, but Silverstone is shaking things up. In ye olden days, the practice fell out of favor, as PSUs ended up sucking in heat rising off the CPU cooler and the video card, which was bad for long-term reliability. In the FT04, however, the power supply has a meshed vent right above it to aid cooling. Just remove a few thumbscrews in the back to slide off the case top and get the PSU inside. The top of the case has a built-in bracket to support the PSU's weight. Minimal heat comes off the GPU right below because the intake fans have been reversed, since the motherboard is flipped. The overall thermal design is much improved from earlier implementations. The side panels has tabs on the back that overlap with the top panel, so you have to remove the sides before taking off the top, then do the same in reverse.

3. Features for Creatures

The X79 Deluxe (not to be confused with the older P9X79 Deluxe) has a number of interesting features. We like the beefy voltage regulators, integrated dual-band 802.11ac Wi-Fi, Bluetooth 4.0, eight SATA 6Gb/s ports, DTS audio, push-button USB-based BIOS updates, and even dual LAN ports and a stainless-steel I/O plate (pictured). The black-and-gold theme is also rather pimp. As an added bonus, the board recognized our Ivy Bridge-E CPU right away. This Intel chip is not a huge upgrade from the Core i7-3960X, but it performs moderately faster and generates a lot less heat. It's a hexa-core chip with Hyper-Threading. Games don't usually make much use of HT, but Battlefield 4 hungrily chews up every available processing thread. So it's nice to have 12.

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4. The Drive to Survive

Ordinarily, there isn't a whole lot to say about installing a couple of storage devices in your average case, but the FT04 is anything but average. It has two cages at the bottom and one large cage in the front, all of which are removable. On the bottom, one cage gets an integrated SATA and power-connection bracket, while the other has a mini-jack for holding up a large air cooler. We said, “por qué no los dos,” and put the bracket and the jack on the same cage, since we didn't need both cages. The FT04 has mounts for screwing up to four SSDs directly into the bottom of the case anyway, so the extra container would just take up space. To remove it, you lay the FT04 on its side and remove the cage screws from underneath, five in all. Being able to remove the screws from within the case is easier, but this will do in a pinch.

5. Air to the Throne

You may wonder why we went with an air cooler in this system, since we're not really holding back in other areas. There are two reasons. One, we wanted to check out the case's built-in heatsink kickstand. It was just too neat of a widget to discard. Two, the FT04 doesn't have many case fan mounts. To put a 240mm radiator in the front, you have to remove two 180mm "Penetrator" fans, which are cool-looking and pre-connected to independent fan controllers. It seemed a shame to take those out of the picture, because they create some excellent airflow while keeping noise levels down. (In fact, the entire case is layered with sound-absorbing foam panels.) Since there are no fan mounts on the top, sides, or bottom, the only other alternative would be the 120mm mount in the rear, which we're already using as an exhaust port. We’d have to replace that with a radiator and fan, blowing outward. Not as thermally efficient as an intake, but you don't have much choice.

Regardless, we opted for air. The FT04 does not ship with a rear fan, so we pulled our Scythe Gentle Typhoon from a box of Dream Machine parts. Waste not, want not.

6. Cable Commentary

Like the Fractal Design Define R4, the Silverstone FT04 is a wide case for its mid-tower form factor, so we have a lot of room to route cables behind the motherboard tray. Some excess power supply cabling can be tucked in the top of the case, as well. We needed the full length of the PSU's 8-pin CPU power cable, but we had overly long cables elsewhere. We used a piece of tape to secure the wiring of the Scythe Gentle Typhoon fan because its cabling is surprisingly stiff and prone to popping out otherwise. A pre-installed sleeve would be nice, considering the relatively high cost of this fan. The Silent Pro Gold's cables are flat and very flexible, so we had no trouble connecting them to the HD 7990 in a presentable way.

Into the Fray

Once we got the system up and running, it was pretty smooth sailing. We had the 13.11 beta Catalyst drivers for the video card, and we were able to keep Battlefield 4 solidly at 60fps at 1080p, with all visual effects cranked to max settings. There were occasional dips into the single digits, but this could be the result of network congestion or unfinished optimization (we were playing the beta version of the game as this issue went to press; and the Mantle version of BF4, which replaces DirectX, is not scheduled for release until mid-December, so we can't test that yet.)

Also of note, BF4 seems happy to take as many CPU processing threads as you can give it, including Hyper-Threading (HT). Six appears to be the magic number; less than that, and the cores get pegged at 100 percent utilization. In addition to this system, we also tried the game on a Core i5-4670K system with dual GeForce GTX 770s, an i7-4770K system with a single GTX Titan, and an AMD FX-8350 system with dual GTX 780s, and then the HD 7990. Enabling HT bumped up performance about 10 percent. However, the FX-8350 could not hit 60fps even with the HD 7990, while an i7 with Hyper-Threading disabled stayed comfortably above that mark when using a GTX 780. Like we said, the game was in a beta state as this issue went to press, so some performance optimizations may have arrived by the time you read this. But right now, the gap between Intel and AMD CPUs is consistent and noticeable (although Premiere Pro spat out some odd results, despite repeated tests).

Temperature-wise, dual 180mm intake fans bring in a lot of external air, and the Lab is temperature-controlled around 70 degrees F. Leaving a single 120mm fan to remove heat didn't seem to be a problem, though the Gentle Typhoon is admittedly very good at air displacement. Still, it seems like a $230 case should offer more options. The top has an intake for the power supply, and it looks like there's plenty of room for a fan mount up there, as well. The similarly priced Thermaltake Level 10 GT has a 230mm fan in the top and on the side, and a bonus mount on the bottom of the case. Of course, its aesthetics are much different. The FT04 is obviously designed to look sleek. But it may sacrifice too much in the process.

Nevertheless, this build felt like a success. We got the performance we wanted, and the system felt very solid and stable. It was also fun to see a game use more than four CPU cores.




Premiere Pro CS6 (sec) 2,000 2,020 (-1%)
Stitch.Efx 2.0 (sec) 831 744
ProShow Producer 5.0 (sec) 1,446 1,309
x264 HD 5.0 (fps) 21.1 24.2
Batmans Arkam City (fps) 76 93
3DMark11 Extreme
5,847 5,684 (-3%)

The zero-point machine compared here consists of a 3.2GHz Core i7-3930K and 16GB of Corsair DDR3/1600 on an Asus P9X79 Deluxe motherboard. It has a GeForce GTX 690, a Corsair Neutron GTX SSD, and 64-bit Windows 7 Professional.

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