Nvidia's GK104 GPU (codenamed Kepler) debuted last month in the form of the GTX 680. Now the company is following up with a slightly less-powerful part aimed at securing a lower price point and going head-to-head with AMD's own Radeon HD 7950. Team Red has already cut prices once since the GTX 680 debuted.
The GTX 670 is targeting the £350 price point - but can already be had for a bit less online - and Nvidia claims its new GPU is significantly faster than the best AMD can offer.
Let's take a look at what Nvidia has brought to the table this time around.
One of the first thing we noticed about the GTX 670 is its size and weight - or lack thereof. It may look like a standard high-end graphics card on top, but Nvidia put Kepler's PCB on a diet. The card comes equipped to cover all your display needs, with two DVI outputs, one HDMI, and one DisplayPort. Flip it over, and it's surprisingly short.
The GTX 670 PCB is approximately 7in long, not counting the PCIe bracket. While this particular card retains a dual-slot design, Nvidia told us that several partners may have single-slot solutions in the works. It's been a long time since top-tier GPUs shipped in such svelte packages and it speaks volumes about GK104, that Nvidia was able to pull this off.
The GTX 670 uses the same GK104 chip as the 680, but with one SM (Streaming Multiprocessor) unit turned off. Kepler's SM groups are referred to as SMXs and were rearchitected, rather than being based on Fermi's. The GTX 670 has just 112 texture units (down from 128) but keeps the GTX 680′s 32 ROPs.
Looking at its spec sheet, the GTX 670 has ~12 per cent fewer cores and clocks them ~12 per cent slower than its big brother. That's a modest step down from the 680, and should keep the card's performance near the top of the chart. We've rounded up two cards to compare to the 670 - a GTX 580, NV's previous top-performing single-GPU solution, and a Radeon 7950 courtesy of AMD. The GTX 580 is still widely available at a similar price to the 670.
We only had a few days to spend with the card, so our coverage will be a bit confined this time around. Nvidia launched a number of new technologies alongside the GTX 680 last month, including what it calls adaptive Vsync, the option to force FXAA (a type of anti-aliasing) on in the control panel, and a new hardware video encode engine, dubbed NVENC. We'll revisit some of these new features and overall image quality in the near future. All of the following benchmarks were run at 1,920 × 1,080 resolution.
We start off with 3DMark 7 as a quick way to examine our three cards at two different presets and in different workloads. The Radeon 7950 maintains a lead over the older GTX 580 in both the preset options, but the GTX 670 soars ahead of both. The gap between the Radeon and the GTX 670 actually increases at the higher performance level, from 17 per cent to 30 per cent.
According to the synthetic tests, the 670 should pull well ahead of the other two cards in real-world games. Let's see if that occurs.
Arkham City is the sequel to the smash hit Arkham Asylum from 2009 and easily one of the best games of 2011. Its DX11 mode was broken when the game launched, but a subsequent patch added an admittedly minimal amount of support for the API. It's a great game in either mode, however, and makes an appearance here as a real-world title with broad appeal.
We tested in two modes: Very High, and Ultra High. In Very High, DX11 and HBAO are both enabled, with tessellation set to "Normal" and no AA. Anisotropic filtering is set to x16 in-driver. Ultra High mode turns tessellation up to "High" and adds 8x MSAA. PhysX is off in both cases - while it adds some nice features and effects, it significantly slows down any system without an Nvidia GPU.
The GTX 670 and Radeon 7950 tie at Very High detail levels, with the GTX 580 significantly behind them. At Ultra High detail, however, this changes. Here, the GTX 670 perches well out in front of its competitors, while the Radeon slumps to last place behind the GTX 580.
Shogun: Total War 2 is a strategy game that blends elements of real-time and turn-based gameplay. In the former mode, large armies gather to bash each other's heads in, all in glorious DX11. We tested two modes - first, the game's "Very High" preset, followed by our own custom Ultra High mode, in which we added 8x MSAA and tuned all of the various variables to their maximum settings.
In Very High mode, the GTX 670 is the overall winner, coming in ~12 per cent faster than the Radeon and 36.5 per cent faster than the GTX 580. This trend collapsed when we increased to Ultra High settings - none of the video cards tested here were capable of maintaining a smooth frame rate under the load. The GTX 580 wins overall, but doesn't really offer a playable frame rate.
99 per cent of the time, when we test a game, that means testing an official version of the product without any mods or add-ons. With Skyrim, we made an exception: Instead of relying on Bethesda's own texture packs, we benchmarked the game with the full Skyrim HD textures installed instead. This substantially increases texture resolution and puts a greater load on modern GPUs. It also drastically improves the overall visual quality of the game, from something a PC might've run five years ago, to something you'd want to play today.
One of the major positive changes to GK104 that Nvidia has hyped is the improvement in the chip's performance per watt. Without time to do a comprehensive write up, we had to resort to some quick-and-dirty testing - but what we found was striking. Check the chip's power consumption in 3DMark's first game test.
We chose this test for expediency, not because NV recommended it - and the GTX 580′s 340W draw is in line with what we'd expect from real-world games. That's what makes the GTX 670′s 230W consumption startling - it's an enormous improvement. Granted, it's not going to have a huge impact on your power bill - even if you gamed 24/7, the difference between the two would come out to around £5 a month. It confirms, however, that Nvidia created Kepler with an eye on what it might do with the chip in the future. A Fermi-style GPU was never going to make it into a mobile part, while a Kepler-derived chip will.
In this case, we're going to insert a note of caution. With very limited time, we chose a test that was expedient and simple. Other websites have demonstrated that the GTX 600 family offers superior performance/watt when compared to the Radeon 7000 series - while our own results demonstrate that this isn't always the case, we want to note the general trend.
Kepler is an awesome chip and the GTX 670 reflects that nicely. There's no doubt that Nvidia has the upper hand at the top of the market, at least on paper. The latter distinction is necessary given that GTX 680s are darn hard to find right now. High-end Radeons, in contrast, are available in volume.
We'll have to watch GTX 670 availability over the next few weeks and see what develops.
As far as direct competition with AMD is concerned, Kepler puts Nvidia back in the driver's seat when it comes to defining performance at a given price point. The good news, for both consumers and AMD, is that the comparison isn't nearly as one-sided as we've sometimes seen in previous generations.
When the GeForce FX or Radeon HD 2000 families launched, there was real reason to question if a person who bought one of these cards would get the level of performance and quality they thought they were paying for. That's not an issue here. The HD Radeon 7000 series has a strong line-up - just not as strong as what Nvidia is serving up.
Thus far, AMD has countered GK104 with price cuts and an emphasis on board partners offering overclocked versions. We expect to see both trends continue, with AMD ultimately positioning the HD 7000 family as a contender in the price/performance ring. The overall crown has passed to Nvidia for now, but that doesn't mean AMD is out of the fight.