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Radeon HD 7950 vs. GeForce GTX 660 Ti revisited


New games, new drivers prompt a rematch
— 4:34 PM on December 4, 2012

Ah, it's the eternal battle, the unending duopoly duel: GeForce versus Radeon, Radeon versus GeForce. The skirmishes are ongoing, but the victor is never decided for long. Today, another chapter in the story unfolds.

Doesn't seem that long ago, back in August, when the GeForce GTX 660 Ti first hit the scene and squared off against the Radeon HD 7950. That match-up ushered in a new generation of competition among ridiculously powerful video cards at around 300 bucks. Nvidia had the advantage going in, since it was facing off against an already established competitor; it knew what the GTX 660 Ti had to do in order to win. AMD, however, has been unusually feisty lately, and it had other ideas. At the last minute, the Radeon team rolled out a new BIOS that added dynamic clock speeds to the 7950. The result was an incredibly slight win for the GTX 660 Ti on points, but in the end, we threw our hands up and said the differences mattered little.

We're vaguely astonished by how much things have changed since then.

Of course, we have a new crop of games for the holiday season, headlined by titles like Borderlands 2, Hitman: Absolution, Sleeping Dogs, and Assassin's Creed III. AMD's newfound aggressiveness means many of these games are part of its Gaming Evolved program, so they should run very well on Radeon graphics cards—and maybe, you know, not so well on those pesky GeForces.

In fact, accentuating its stronger ties to game developers, AMD has taken to bundling a trio of these games with its Radeon HD 7950 cards. Cramming that sort of gaming goodness into the box with a graphics card certainly changes the value equation.

As if that weren't enough, AMD has also released Catalyst 12.11 beta drivers that promise a roughly 15% across-the-board performance increase for its 7000-series Radeons. New drivers often bring performance gains for individual games, but general improvements of that magnitude are uncommon. AMD tells us it has employed new insights in tuning its relatively young GCN architecture.

What's more, Windows 8 is out, and we've transitioned our test rigs to the new operating system.

Add up all of these changes, and you have a recipe for realignment in ongoing battle for GPU supremacy. Are we still at rough parity, or have AMD's bold moves allowed it to push into the lead? We've deployed our infamous "inside the second" testing methods with a host of the latest games in order to find out.

Our lovely contestants


Pictured above is the Sapphire HD 7950 Vapor-X, our representative from the Radeon camp for this little hoedown. The 7950 Vapor-X is our first look at a retail product with the new Boost BIOS, and it ups the ante by sporting a peak Boost clock of 950MHz, 25MHz above stock. Sapphire's Vapor-X cooler sprouts quad heatpipes that snake into a large array of cooling fins situated beneath dual fans. The shroud that covers the whole assembly may be the finest expression of the F-117 Stealth fighter look that has rampaged through the enthusiast PC hardware scene in recent years. Although it sticks out maybe a quarter-inch beyond the 10.5" length of the card itself, there's no way that thing shows up on radar.


The HD 7950 Vapor-X sells for $329.99 at Newegg and comes with a bunch of inducements to buy, including copies of Sleeping Dogs, Hitman: Absolution, and Far Cry 3, along with a 20%-off coupon for Medal of Honor: Warfighter. There's also a $20 mail-in rebate attached right now. If you buy two, AMD CEO Rory Read will come to your house and personally serenade you from outside of your window. I hear he has quite the voice.

Looking over the listings at Newegg, 7950 cards are going for as little as $299.99. However, only a few other cards can match the Vapor-X's 950MHz boost clock, and they all cost more than the Sapphire.


We've pitted the HD 7950 Vapor-X against our returning champ from the GeForce side, the Zotac GTX 660 Ti AMP. This baby sports Zotac's charming "angry bumblebee" look but is scaled down massively from its GTX 670 and 680 brethren. The card is only 6.75" long, giving it a distinctive miniature vibe we like to call "low BOM cost chic."

There's something to be said for keeping costs down, though. The GTX 660 Ti AMP! is currently going for $299.99, even though it's a hot-clocked card. In fact, the Zotac's boost frequency is one of the highest among the GTX 660 Ti cards available. Also, its 6.6 GT/s memory is 10% faster than most of its competitors, even though they cost as much as 350 bucks.

In a bid not to be totally left behind by AMD's cornucopia of bundled games, most GTX 660 Ti cards right now (including the AMP!) come with a free copy of Assassin's Creed III. Also, Zotac currently matches Sapphire's $20 rebate offer with its own, for those who enjoy filling out microscopic forms.


Base
clock
(MHz)
Boost
clock
(MHz)
Peak
ROP rate 
(Gpix/s)
Texture
filtering
int8/fp16
(Gtex/s)
Peak
shader
tflops
Memory
transfer
rate
Memory
bandwidth
(GB/s)
Sapphire HD 7950 Vapor-X 850 950 30 106/53 3.4 5.0 GT/s 240
Zotac GTX 660 Ti AMP! 1033 1111 27 124/124 3.0 6.6 GT/s 159

Although they're positioned against each other in the market, these two cards really are somewhat different classes of hardware, as both the picture and table above illustrate. The 7950 is based on a slightly cut-down Tahiti GPU with a 384-bit memory interface. The GTX 660 Ti's interface is half that width at 192 bits. The Radeon has the theoretical advantage in ROP rate, shader flops, and memory bandwidth—and the gap is quite large, in the last case. The 7950 has 3GB of memory, too, while the 660 Ti has 2GB. The GeForce can eclipse it only in texture filtering prowess.

The 7950 even has more appetite for power, requiring six- and eight-pin auxiliary inputs, while the GTX 660 Ti gets away with dual six-pin plugs.

Still, Nvidia's Kepler architecture has proven to be shockingly efficient in many cases, so the GTX 660 Ti's lower specs won't necessarily translate into lower performance. That's why we test these things. Speaking of which...