GK104 Rides Again In GeForce GTX 770

GK104 Rides Again In GeForce GTX 770

Nvidia had some room to tune and tweak GK110 to create GeForce GTX Titan, 780, and whatever else the company might do with the GPU, since the products based on this 7.1-billion-transistor chip are trimmed-back versions with 12 or 14 out of 15 total Streaming Multiprocessors enabled.

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But the GK104 processor at the heart of GeForce GTX 680 is already fully-featured. The chip plays host to four Graphics Processing Clusters, each with two SMXes, and they’re all turned on. So how is Nvidia able to build a GeForce GTX 770 on the same piece of silicon? A couple of different ways. First, it turns up the clock rates on GK104. The 770’s base clock rate is 1,046 MHz (up from 1,006 MHz on GTX 680) and its rated GPU Boost speed is 1,085 MHz (up from 1,058 MHz). Second, it delivers more memory bandwidth through the same 256-bit interface. GeForce GTX 680 employed 2 or 4 GB of GDDR5 at 1,502 MHz. GeForce GTX 770 is going to be available with the same capacities running at 1,752 MHz, or 7 Gb/s.

GeForce GTX 770: Nice Genes!The 3.54-billion-transistor GPU’s other vitals map over nicely. To recap, GK104 boasts eight SMX blocks, each with 192 CUDA cores and 16 texture units. All told, you get 1,536 CUDA cores and 128 texture units. Four ROP partitions capable of eight 32-bit integer pixels per clock add up to 32. And a quartet of 64-bit memory interfaces form an aggregate 256-bit pathway.

We’re officially spoiled. The last three Nvidia cards to come through our SoCal lab all featured the company’s more aggressive industrial design, typified by an aluminum housing, a polycarbonate window with a view down into a beefy heat sink, and an LED-backlit GeForce logo that’s controllable through an API Nvidia makes available to its partners. In comparison, the plastic-covered GeForce GTX 680 and Radeon HD 7970 selling in that $450 range look so…vanilla.

Aesthetically, GeForce GTX 770 looks like 780, which looks like Titan. This is the same 10.5-inch PCB, metal shroud, clear window, and centrifugal fan responsible for exhausting heat out the back of the card’s I/O panel.

When you consider that Nvidia gives the GeForce GTX 770 a 230 W TDP (20 W less than Titan and 780), this thermal solution is very likely overbuilt for GeForce GTX 770—and that bodes well for overclockers hoping to push GK104 a little harder than the factory.

Of course, despite its lower TDP, you still need one eight- and one six-pin auxiliary power connector; Nvida recommends using a power supply with at least 600 W of output.

Display output is unchanged. GeForce GTX 770 drives up to four simultaneous screens through two dual-link DVI ports, one HDMI connector, and a single DisplayPort interface.