Going back to basics
Those folk over at Nvidia sure know how to wring the most out of a particular graphics processing unit. The current Kepler architecture, first seen on the ageing GeForce GTX 680, has now been propagated to a number of high-end 7-series desktop cards and a large chunk of the firm's mobile chips.
The latest desktop entry to cross our path was the GeForce GTX 770, which, truth be told, was not much more than an overclocked GTX 680 encased in a new cooler and sporting a couple of new tricks by way of GPU Boost v2.0.
Guess what? Nvidia is rolling out yet another 7-series GPU today, making hay while arch-rival AMD wrestles with what to do next. This new card is the GeForce GTX 760 and, would you believe it, this apparently 'new' GPU takes an awful lot in the way of design cues from the incumbent GTX 670 and GTX 660 Ti.
We expect partners to release board packages from £210, thereby putting the GTX 760 at roughly the same price as a GTX 660 Ti and, looking over to the red team, between the Radeon HD 7950 (£220) and HD 7870 (£170).
So what GK104 (Kepler) silicon finagling has Nvidia engaged in when pulling and pushing the Kepler architecture in order to meet a particular price point? Let's spill the details with the Table of Doom™.
| GPU | GeForce GTX 670 (2,048MB) | GeForce GTX 760 (2,048MB) | GeForce GTX 660 Ti (2,048MB) | Radeon HD 7950 (3,072MB) | Radeon HD 7870 (2,048MB) |
|---|---|---|---|---|---|
| Launch date | May 2012 | June 2013 | August 2012 | January 2012 | March 2012 |
| DX API | 11.1 | 11.1 | 11.1 | 11.1 | 11.1 |
| Process | 28nm | 28nm | 28nm | 28nm | 28nm |
| Transistors | 3.54bn | 3.54bn | 3.54bn | 4.3bn | 4.3bn |
| Approx Die Size | 294mm² | 294mm² | 294mm² | 352mm² | 352mm² |
| Processors | 1,344 | 1,152 | 1,344 | 1,792 | 1,280 |
| GPU Boost | v1.0 | v2.0 | v1.0 | AMD-specific | N/A |
| Texture Units | 112 | 96 | 112 | 112 | 80 |
| ROP Units | 32 | 32 | 32 | 32 | 32 |
| GPU Clock/Boost (MHz) | 915 (980) | 980 (1,033) | 915 (980) | 800/925 | 1,000 |
| Shader Clock/Boost (MHz) | 915 (980) | 980 (1,033) | 915 (980) | 800/925 | 1,000 |
| GFLOPS | 2,460 | 2,258 | 2,460 | 2867+ | 2,560 |
| Memory Clock (MHz) | 6,008 | 6,008 | 6,008 | 5,000 | 4,800 |
| Memory Bus (bits) | 256 | 256 | 192 | 384 | 256 |
| Max bandwidth (GB/s) | 192.2 | 192.2 | 144.2 | 240 | 153.6 |
| Power Connectors | 6+6 | 6+6 | 6+6 | 6+6 | 6+6 |
| TDP (watts) | 170 | 170 | 150 | 180 | 175 |
| GFLOPS per watt | 14.47 | 13.28 | 16.4 | 15.93 | 14.63 |
| Current price | $349 | $249 | $299 | $299 | $249 |
Analysis - 6-series heritage shines through
GTX 760 can genuinely be thought of as a GTX 670/660Ti in many ways though it loses an entire SMX unit that's home to 192 processors and 16 texture units. The new GPU makes up some of the performance shortfall by clocking at a higher frequency than the 6-series parts. Illustrating this point, the peak GFLOPS throughput is only nine per cent lower than a GTX 670.
Nvidia first implemented 7Gbps GDDR5 memory on the GTX 770 GPU, but this is considered too expensive to be used on a cheaper card. Carrying the same 32 ROPs, 256-bit-wide memory bus and 6,008MHz-rated GDDR5 as the GTX 670/660 Ti , the backend of the GTX 760 is the same.
Really, GTX 760 can be thought of as the GTX 660 Ti in reverse, because whereas the 660 variant kept the same top-end as GTX 670 but reduced the memory partition down from 256 bits to 192 bits, GTX 760 goes the other way, prioritising bandwidth over cores. This should mean the GTX 660 Ti has the upper hand at lower resolutions while GTX 760's extra bandwidth tells when the load is increased.
The question then arises of why Nvidia would go to the trouble of having a new GPU that's ostensibly similar, albeit slower than the GTX 670; why not rebrand current cards, change specifications just a little, and reduce the price to partners and distributors? Well, the cynical approach is to say that Nvidia has done entirely this, because the GTX 760 is not much more than a core-restricted, higher-clocked GTX 670.
We remain uncomfortable with new-generation GPUs using extant technology that's been slightly modified to fit a price point. At least AMD had the wherewithal to keep model numbering to the same generation when it released the HD 7870 XT.
The GeForce GTX 760 is the least-deserving of the 7-series GPUs to carry the new name; its provenance lies squarely with the 6-series that's been out for more than a year. Yet common sense dictates that any GPU, irrespective of underlying technology, can be considered a good deal if priced attractively enough. US pricing for a reference-like card is a rather tasty $249, which is very sensible given the way in which current GeForces and Radeons line up, but we fear that UK retailers are likely to charge more than £200 from the get-go.
Does a £200 GTX 760 make sense in mid-2013? Let's take a look at the card and then evaluate performance on some of the hottest gaming titles.
