In the battle for gaming graphics supremacy, nVidia is playing its dual-GPU card to create the nVidia GeForce GTX 590, the fastest nVidia gaming card now available. But how does it stack up against AMD's competing ATI Radeon HD 6990?
The launch in 2006 of the GeForce 7900 GX2 was something of a momentous event for the graphics chip market. Although a few board manufacturers had attempted something similar, the 7900 GX2's release marked the first time that a major graphics chip manufacturer had combined two chips within the same product.
The dual-GPU hasn't always had an easy ride, but it has long since become the established way for the card duopoly of nVidia and ATI can create the highest-performance cards in each generation of products. Following hot on the heels of the ATI Radeon HD 6990 comes this reply from nVidia.
What becomes immediately obvious is that the nVidia GTX 590 seems to lack the no-holds barred ambition of the 6990. Whereas the latter is a full-throated assault against everything that's modest and quiet, the nVidia GTX 590 is less showy.
Around 20mm shorter and less heavy, the nVidia GTX 590 lacks the startling bulk of the 6990. It's by no means a small product, and you'll still need to make sure your PCI-E slots have plenty of space around them. Also present is the need to attach a pair of 8-pin connectors to the PSU.
Given the smaller size, it's perhaps a surprise that the nVidia GTX 590's thermal design power (TDP) of 365W is only 10 watt lower than the 6990's figure of 375W; although the nVidia GTX 590 was noticeably quieter and generated less heat in general.
The nVidia GTX 590 is less advanced in some respects, and it sticks to the tried and tested array of DVI ports - three of these are provided. A single Mini DisplayPort connector is offered as well, in contrast to the four built into the 6990.
While the 6990's approach means having to use inelegant dongles to convert the Mini DP ports to more mainstream HDMI or DVI versions, it does mean that the nVidia GTX 590's potential capabilities are restricted when it comes to multi-screen systems - nVidia GTX 590 users will only be able to hook up four screens at once, rather than the 5+ of the 6990.
Two in one
The nVidia GTX 590 essentially takes two GTX 580 chips and makes them work in tandem. As with most dual-GPU solutions, the clock speeds have been cut in order to accommodate both GPUs without adding too much to the load.
But while the cuts were relatively modest in the case of the similarly high-end ATI Radeon HD 6990, the nVidia GTX 590 sees savage reductions.
For example, compared with the Zotac version of the nVidia GTX 580, the GTX 590 sees its core-clock speed fall from 772MHz to a mere 607MHz. This is a quite dramatic fall.
The memory clock speed drop, from 1002MHz (4008MHz with DDR GDDR5 memory taken into account) to 853.5MHz (3414MHz DDR effective), is also precipitous.
And if these economies compared to the 6990 weren’t enough, then there are other areas where the nVidia GTX 590 is inferior.
The 3GB of GDDR5 is smaller than the 6990's 4GB complement, although the dual memory interface (each of the two chips has a 384-bit version) does see the GTX 590 strike back.
Its 1024 stream processors are some distance behind the 6990's tally of 3072, although it does have 96 ROPs (Raster Operations), half as many again as the 6990.
So the nVidia GTX 590 is a mixed bag as far as the specifications go, beating the 6990 in some areas, but losing out in many others.
In the end, it was perhaps the nVidia GTX 590's greater ROP units that allowed it to register a win in the Battleforge tests. At a resolution of 1920x1200 (for a chip of this power, anything below that resolution simply isn't pushing the card at all) the 590 scored 91.0 frames per second (fps) in answer to the 6990's 87.7fps.
Otherwise, it generally finished a handful of frames behind the ATI.
In Heaven its score of 55.3fps was 2.7fps down on the 6990's 58.0, while in Stalker: Call of Pripyat it tallied only 75.6fps to the Radeon's 83.2.
In Crysis it finished marginally down, 2.4fps behind the 6990's 49.5fps.
In all cases it remained a long way clear of the ATI Radeon HD 6950, almost doubling its scores in every test.
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