The Asus GeForce GTX Titan took us rather by surprise when it appeared earlier this year. We're less surprised now to be looking at the nVidia GeForce GTX 780 graphics card. Particularly so given that this is really just another Titan, only with access to some areas barred.
That may not sound like a recipe for success on a card that costs around £600. But given that the Titan was something of a colossus, it can afford to lose the odd limb and still bestraddle the graphics chip world with something approaching nonchalance. See Group test: what's the best graphics card?
Both cards are based on the GK110 GPU, but some of the Titan's units have been cut. The Titan's 2688 stream processors and 224 texture units, for example, have both been sliced by a seventh - to 2304 and 192 respectively.
Not that it's cuts all the way, though. The number of raster operations remains at 48, and (crucially for any chip looking to slay the competition) the 384-bit memory interface remains. And, in fact, there are even a few increases.
Despite costing around half the price, the GTX 780 has an 863 MHz core clock (with boost sending it to 900 MHz) as opposed to the 837 MHz (876 MHz) on that corking Titan.
In terms of texture fills, even with that increase, the 780 remains far behind, with 172.8 GT/s to the Titan's 196.2 GT/s. Nonetheless, compared to the 780's competitors, these figures remain very good. The AMD Radeon 7970, for example, has just 128 texture units, and can only muster 118.4 GT/s. The GTX 680 and 770 fare slightly better, but still record figures of only 135.4 and 138.9 GT/s respectively.
The GTX 780 has only half the memory of the Titan's 6 GB, but it's hard to see 3 GB not proving sufficient for most high-resolution games, even two or more years down the line. And in terms of memory specifications, the 780 is otherwise essentially identical to the Titan, offering the same 384-bit interface and 1502MHz memory clock (effectively 6008 MHz taking into account the clock-quadrupling of the GDDR5). Fairly obviously, this amounts to the same high memory bandwidth figure of 288.4 GB/s. This rather dwarves the 224 GB/s of the GTX 770, and also, to a lesser extent, the 264 GB/s of the 7970. See all PC Components and Upgrades reviews.
Asus GeForce GTX 780 3GB: Performance
In our test, the 780 was very close in performance to the Titan, although like that card, it's quite a few frames adrift of the dual-chip 690.
In Crysis 3, the 780 notched up 48.4 and 28.7 fps at resolutions of 1920 x 1080 and 2560 x 1440 respectively. The Titan was marginally ahead on 49.2/29.5 fps, with the 690 finishing on 54.8/38.6 fps. Significantly, the GTX 770 was some way back on 42.5/23.9fps.
The 780 and Titan were very close together in Bioshock, too, with the 780's scores of 89.5/55.0 fps matching up fairly well too the Titan's 91.9/58.8 fps. Only at the higher 2560 x 1440 resolution did the Titan's lead open out to 3.8fps. The GTX 690 was again some distance ahead, on 100.8/69.6 fps.
At the other end of the scale, the GTX 770 scored just 73.3/45.2 fps, leaving it trailing a long way behind.
In Stalker: Call of Pripyat, the 780 fell a greater distance away from the Titan, scoring 114.3/82.2 fps to the Titan's 121.7/91.0 fps. The 690 was again far ahead, on 137.3/101.6 fps. The GTX 770 finished on 102.0/74.3fps.
Overall, then, the 780 is slower than the Titan, but the difference often only amounts to a few frames. Certainly, given the price difference, the 780 is a better value gaming card.
All of this might raise the question, why is the Titan around £300 more expensive, when many of its specifications are close to, and quite often identical to, those of the 780?
Well, in all honesty, the Titan was never designed to be a gaming card. Its huge advantage was the fact that it was the first card that could carry out high-end Compute instructions at an 'affordable' price – and by affordable, we mean a thousand rather than several thousand pounds.
Given that gamers had no real need for features like the sophisticated double-precision floating point capabilities of the Titan, it was always likely to remain uninteresting to all gamers, except those with very substantial bank balances. It's this part of the Titan that has been dramatically suppressed in the 780. So if you're a professional who needs the card for Compute purposes, only the Titan will do. And if you simply want the best gaming, only the 780 makes economic sense.
There's also one other peculiar feature of this card. We said earlier that it was effectively the Titan with one or two missing limbs. Well, strangely, you won't know exactly which limbs will be lopped off when you buy.
The sophistication of this product is such that it's very hard to manufacture without defects, and the defects will appear in different places in every chip. So while nVIDIA will guarantee that a 780 will have 12 working Streaming Multiprocessors (or SMXes), it can't guarantee exactly which will work.
It has to be said that, even in the case of the high-end Titan, only 14 of a maximum 15 SMXes will be working. And from an end-user point of view, it's pretty irrelevant which do and don't work, as everything will pull together to create one cohesive whole. However, it is strange to think that every GTX 780 will, technically, be slightly different from most other 780 examples.
It's partly the design issues that causes the 780 to have the same 250 watt TDP as the Titan, despite being less powerful as a card. Essentially, relaxing the demands means nVidia don't have to throw out as many chips.
In testing, we found the difference between this and the 225W GTX 770 to be less than 20 watt. However, it is significantly tougher on power than the 195W GTX 680, for instance, and in real-world testing, we sometimes found the gap to be bordering on 65 watt.
The 780 is relatively quiet, though, and the nVidia GeForce GTX 770 was only quieter by a decibel – the 680, in contrast, was almost 2dB louder than the 780. The two latest GTX designs may not be focusing on low power consumption in the same way as the 2012 crop were, but attempts at keeping the noise down have improved significantly.