Single page Print

Nvidia's GeForce GTX 660 Ti graphics card reviewed


Kepler squeezes just under 300 bucks
— 8:00 AM on August 16, 2012

Nvidia's GK104 graphics chip has been all over the place since its initial release back in March. The chip made its debut aboard the GeForce GTX 680, a decidedly high-end card priced at $499. About six weeks later, the GeForce GTX 670 arrived, with a slightly scaled down version of the GK104 for $399. Today, onboard the GeForce GTX 660 Ti, this same graphics chip steps down to the much more accessible price point of $299—while again giving up a relatively small amount of performance. If you've been holding out on upgrading to the latest generation of graphics cards, the GTX 660 Ti may finally overcome your resolve.

Here's one way to think about it. In de-tuning the GK104 in order to make this more affordable version, Nvidia has taken the GeForce GTX 680 and shaved off two Xbox 360 consoles worth of graphics processing power. Not to worry, though: the GTX 660 Ti still has 14 or so Xboxes left.

The nitty gritty
To be more specific, for the GTX 670, one of the GK104's eight SMX units was disabled, reducing the shader ALU count from 1536 to 1344 and cutting texture filtering power from 128 to 110 texels per clock cycle. Clock speeds were dialed back a bit, too. Trimming those resources had its impact on overall performance, but it was relatively minimal. Our experience with the GTX 670 caused us to declare that we "fail to see the point of spending more on a GeForce GTX 680."

The GTX 660 Ti retains the SMX lobotomy and adds a couple more tricks to cut costs and rein in performance. First, the GK104's path to memory has been reduced in width from 256 bits to 192. Strangely, though, the card still has 2GB of GDDR5 memory, not the odd number one might expect. To make such a configuration possible, four of the GK104's memory controllers have been configured to run in 16-bit mode, while the other four remain in their native 32-bit mode. Thus, memory bandwidth has been trimmed by 25%, but total memory capacity is still a nice, round number. Second, one of the GK104's four ROP partitions has been disabled, reducing the chip's pixel fill rate and antialiasing power by a quarter.

Those calibrations were apparently sufficient in Nvidia's view to keep this card separate from its elder siblings. The GTX 660 Ti runs at the exact same 915MHz base and 980MHz boost clocks as the GTX 670. Crunch all the numbers, and here's how the cards' key specs end up looking.

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)
Price
GeForce GTX 660 Ti 915 980 24 110/110 2.6 6.0 GT/s 144 $299
GeForce GTX 670 915 980 31 110/110 2.6 6.0 GT/s 192 $399
GeForce GTX 680 1006 1058 34 135/135 3.3 6.0 GT/s 192 $499

The GTX 660 Ti gives up a little bit of ROP throughput and some memory bandwidth versus the GTX 670, but it still offers a whole lotta Kepler GPU power for a hundred bucks less. We suspect that for a great many folks, this class of graphics card will be more than sufficient.

Nvidia is hoping to entice those who currently own older cards in roughly the same class, such as the GeForce GTX 260 or 470, to upgrade to the new hotness. To sweeten the pot, GeForce GTX 660 Ti cards will come with a really, really attractive incentive: a coupon good for a free copy of Borderlands 2. Of course, you'll have to wait for the game's mid-September release date in order to play, but Borderlands 2 is easily the most anticipated title of 2012 within the dank confines of Damage Labs. I will probably disappear for a week or so in September, going vault hunting. Since this game is slated to cost 60 bucks, I'd consider the bundled copy a very nice bonus, to say the least.

Several options
The GTX 660 Ti is slated to be available at online retailers starting today, and indications point to a pretty wide release. We already have three different examples of retail cards on hand for testing.



We'll start with PNY's offering, since it kind of sets the bar. This card is based on Nvidia's reference design (the same one used for the GTX 670), runs at the GTX 660 Ti's stock speeds, and lists for $299.99. No real wrinkles there.

If you're contemplating installing one in your PC, here are the basics. Like the GTX 670 before it, this card is 9.5" in length, but the board itself is only 6.8". The extra length is just... male enhancement. The board's max power rating is 150W, and it requires a pair of six-pin aux power inputs. The display output array is visible above; it mirrors that of other GK104-based cards.

PNY's pitch for this product is straightforward enough. Although higher-clocked variants of the GTX 660 Ti will be a bit faster, this card ought to be adequate for most gamers, and the price is right. Also, Nvidia's reference coolers are often quite decent. While all of those things are true, we're a little dubious about this particular reference cooler; it didn't impress us aboard the GTX 670. We'll have to see how it fares here.


Next up is MSI's GeForce GTX 660 Ti Power Edition. This card has tweaked base and boost clocks of 1019 and 1097MHz, although its memory operates at a stock 6 GT/s.

You might have guessed that little else about this puppy is stock. MSI has customized the PCB design, adding an additional power phase, to yield a 5+2 config (versus 4+2 in the reference cards). Then there's the slick custom cooler, with twin fans and quad heatpipes, whose aluminum fins stretch the 9.5" length of the board. MSI rates this card for 190W max power, and its design should facilitate overclocking. If you like to live dangerously, the firm claims the Power Edition can achieve "triple overvoltage" via its excellent Afterburner overclocking utility.

MSI plans to charge a premium of just 10 bucks for these extras. You should see the Power Edition at online retailers for $309.99.


Finally, Zotac's hopped-up variant of the GTX 660 Ti is pictured above next to its GTX 670 big brother.

I'm sorry, but it is so cute.

The circuit board is under 7" long, and the card measures 7.5" to the pointed tip of its cooling shroud. Unlike its similarly styled siblings, the Zotac GTX 660 Ti AMP! Edition occupies only two expansion slots—and it is totally primed to slip into a compact Mini-ITX enclosure of some sort.

Believe it or not, this little dynamo is also the fastest of these three GTX 660 Ti cards. The 1033MHz base and 1111MHz boost clocks and 190W TDP are similar to the MSI's, but Zotac adds much faster GDDR5 memory, with a 6.6 GT/s transfer rate. Not surprisingly, then, the price tag is a little steeper at $329.99.

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)
Price
PNY  GTX 660 Ti 915 980 24 110/110 2.6 6.0 GT/s 144 $299
MSI GTX 660 Ti OC 1020 1098 26 123/123 3.0 6.0 GT/s 144 $309
Zotac GTX 660 Ti AMP! 1033 1111 27 124/124 3.0 6.6 GT/s 159 $329

All told, the differences between these three products aren't earth-shattering, but it's worth noting that the two hot-clocked models actually eclipse the stock GTX 670 in terms of peak theoretical texture filtering and shader FLOPS rates.