AMD Radeon HD 7990: Eight Games And A Beastly Card For $1,000

AMD's Malta Becomes The Radeon HD 7990

Time flies. We published AMD Radeon HD 7970: Promising Performance, Paper-Launched almost a year and a half ago. The graphics card market was quite a bit different back then. AMD’s virginal Graphics Core Next architecture made its debut against Nvidia’s Fermi-based GeForce GTX 580, absolutely blowing the company’s own Radeon HD 6970 out of the water in the process.

And a dual-GPU card, based on two of the 7970’s Tahiti GPUs was rumored to be right around the corner. We waited. And we waited.

Of course, in the 12 months that followed, no official Radeon HD 7990 surfaced. Rather, board partners tentatively dipped their toes into that high-end space. PowerColor got out ahead of the rest with a dual-Tahiti offering that consumed three expansion slots, required three eight-pin auxiliary power connectors, and screamed like a banshee any time we applied a load to it. HIS followed suit, giving us exclusive access to a couple of prototypes before withdrawing its plans to ship a dual-GPU solution altogether. Finally, Asus threw its hat into the ring with a liquid-cooled card of its own, as obscenely-priced and limited as it was. We looked at all of them in Asus' ROG Ares II: Four Dual-GPU Graphics Cards, Compared, eventually coming to the conclusion that Nvidia’s GeForce GTX 690, while a bit slower in our benchmarks, made more sense than any of the Radeons.

Challenge accepted, AMD said. Today we have a real, actual Radeon HD 7990, straight from the company’s own product team. It’s a dual-slot card. It only requires two eight-pin power connectors. And—brace yourself—its fans spin quietly. That’s not to say the 7990 is silent, but more on that later.

Hold Nothing Back In The Name Of Performance

Stripped down to its bare PCB, the Radeon HD 7990 consists of two Tahiti GPUs, each surrounded by 3 GB of GDDR5 memory and connected by a PLX Technology PEX 8747 switch.

The graphics processors are complete—AMD doesn’t disable any of their resources, so each brings 2,048 Stream processors to the table, along with 128 texture units, 32 ROPs, and an aggregate 384-bit memory bus. The company even sets the GPUs to operate at 950 MHz, with a 1 GHz boost state. That’s a little faster than the vanilla Radeon HD 7970, and a bit slower than the later GHz Edition version, which starts at 1 GHz and accelerates to 1.05 GHz.

The 3 GB of GDDR5 memory attached to each GPU runs at 1.5 GHz, just like AMD’s Radeon HD 7970 GHz Edition (in comparison, the original 7970 launched with a 1,375 MHz memory clock), delivering up to 288 GB/s per GPU.

Nestled between the two 4.3 billion-transistor chips is that PEX 8747 switch—the same one Nvidia uses to enable inter-GPU communication on the GeForce GTX 690. The 48-lane, five-port device is manufactured at 40 nm and is PCI Express 3.0-capable. So, it attaches to each GPU through a 16-lane link, and then to the host interface with an additional 16 lanes.

All of that hardware is used to enable up to five simultaneous display outputs, one of which comes from dual-link DVI and four of which get exposed through mini-DisplayPort connectors. In comparison, Nvidia’s GeForce GTX 690 can only do four monitors in a three-plus-one configuration. Five screens in a 5 x 1 arrangement make far more sense to productivity-oriented enthusiasts.

At least based on its raw specifications, the Radeon HD 7990 is technically closer to two 7970 GHz Editions in CrossFire than GeForce GTX 690 is to two 680s in SLI. And given the massive performance boosts we’ve seen from AMD’s driver team over the last year, the paper promise is a compelling advantage that should make this the fastest dual-slot graphics card in existence. Now, what about the rest of the board’s vitals?

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Header Cell - Column 0 Radeon HD 7990Radeon HD 7970 GHz Ed.GeForce GTX TitanGeForce GTX 690GeForce GTX 680
Shaders2 x 2,0482,0482,6882 x 1,5361,536
Texture Units2 x 1281282242 x 128128
Full Color ROPs2 x 3232482 x 3232
Graphics Clock950 MHz1,000 MHz836 MHz915 MHz1,006 MHz
Texture Fillrate2 x 121.6 GT/s128 Gtex/s187.5 Gtex/s2 x 117.1 Gtex/s128.8 Gtex/s
Memory Clock1,500 MHz1,500 MHz1,502 MHz1,502 MHz1,502 MHz
Memory Bus2 x 384-bit384-bit384-bit2 x 256-bit256-bit
Memory Bandwidth2 x 288 GB/s288 GB/s288.4 GB/s2 x 192.3 GB/s192.3 GB/s
Graphics RAM2 x 3 GB GDDR53 GB GDDR56 GB GDDR52 x 2 GB GDDR52 GB GDDR5
Die Size2 x 365 mm2365 mm2551 mm22 x 294 mm2294 mm2
Transistors (Billion)2 x 4.314.317.12 x 3.543.54
Process Technology28 nm28 nm28 nm28 nm28 nm
Power Connectors2 x 8-pin1 x 8-pin, 1 x 6-pin1 x 8-pin, 1 x 6-pin2 x 8-pin2 x 6-pin
Maximum Power375 W250 W250 W300 W195 W
Price (Street)$1,000$430$1,000$1,000$460
Chris Angelini
Chris Angelini is an Editor Emeritus at Tom's Hardware US. He edits hardware reviews and covers high-profile CPU and GPU launches.
  • blackmagnum
    If I had 1,000 dollars... I would buy a Titan. Its power efficiency, drivers and uber-chip goodness is unmatched.
  • whyso
    Power usage?

    Thats some nice gains from the prototype driver.
  • ilysaml
    Nice article!! Unbeatable performance out of the box.
  • 17seconds
    Sort of seems like a mess to me. The game bundle is nice.
  • timw03878
    Here's an idea. Take away the 8 games at 40 bucks a piece and deduct that from the insane 1000 price tag.
  • donquad2001
    this test was 99% useless to the average gamer,Test the card at 1900x1080 like most of us use to get a real ideal of what its like,only your unigine benchmarks helped the average gamer,who cares what any card can do at a resolution we cant use anyway?
  • cangelini
    whysoPower usage?Thats some nice gains from the prototype driver.Power is the one thing I didn't have time for. We already know the 7990 is a 375 W card, while GTX 690 is a 300 W card, though. We also know AMD has Zero Core, which is going to shave off power at idle with one GPU shut off. I'm not expecting any surprises on power that those specs and technologies don't already insinuate.
  • ASHISH65
    nice article! here comes the Competitor of gtx 690!
  • cangelini
    donquad2001this test was 99% useless to the average gamer,Test the card at 1900x1080 like most of us use to get a real ideal of what its like,only your unigine benchmarks helped the average gamer,who cares what any card can do at a resolution we cant use anyway?If you're looking to game at 1920x1080, I can save you a ton of money by recommending something less than half as expensive. This card is for folks playing at 2560 *at least.* Next time, I'm looking to get FCAT running on a 7680x1440 array ;)
  • hero1
    Nice article. I was hopping that they would have addressed the whining but they haven't and that's a shame. Performance wise it can be matched by GTX 680 SLI and GTX 690 without the huge time variance and runt frames. Let's hope they fix their whining issue and FPS without forcing users to turn on V-sync. For now I know where my money is going consider that I have dealt with AMD before:XFX and Sapphire and didn't like the results (whining, artifacts, XF stops working etc). Sorry but I gave the red team a try and I will stick with Nvidia until AMD can prove that they have fixed their issues.