A new mid-range entry
It's nice to park the Benz in the garage and kick back with a game of Quake 4 on the ol' 7900 GT, but no member of the 7900 series is really poised for mass market success. Instead, that role has fallen to NVIDIA's other new 90nm graphics processor, the G73. In order to appeal to the Honda Accord set, the G73 design team fired up the world's smallest chainsaw and cut a G71 in half. They'd probably tell you it's more complicated than that, what with their engineering degrees and fancy chip design tools, but the G73's specs tell the story: five vertex shaders, three pixel shader "quads" for a total of 12 units, and eight ROPs to convert fragments into true pixels. Even the memory interface is halved, from 256 bits to 128.
The G73's DNA matches that of the G71, right down to the bits about improved SLI antialiasing and shorter pipelines than previous 7-seres GPUs. The G73 shares pretty much all of the same non-3D-graphics logic with the G71, including NVIDIA's PureVideo video processing engine. However, this lower-end part comes with one dual-link TMDS transmitter and a second single-link one.
The G73 GPU
Cheaper chips make for cheaper cards, and the G73 looks promising on that front; its 178 million transistors reside in a space only 125 mm2. Contrast that, if you will, to ATI's mid-range graphics processor, the RV530, also known as the Radeon X1600 GPU. Also a 90nm part, the RV530 weighs in at about 132 mm2. ATI has given the RV530 a healthy 12 pixel shader units, much like the G73, but the RV530 can only lay down four textures per clock and can only write out four pixels per clock to the frame buffer. Each of the G73's 12 pixel shader units can also act as texture units, and the G73's eight ROPs can write out as many as eight pixels in each clock cycle. In the right configuration, the G73 might put the X1600 to shame.
That configuration may have just arrived in the form of the GeForce 7600 GT, the first G73-based video card and the long-awaited replacement for the immensely popular GeForce 6600 GT. With a 560MHz core clock and a matching 560MHz vertex clock, the 7600 GT will possess some serious fill rate muscle: 6.72 billion texels per second, just a touch under the 6.8 gigatexels/s of the GeForce 6800 Ultra and well above the anemic 2.36 gigatexels/s of the Radeon X1600 XT. With GeForce 7-class pixel shader units, the 7600 GT should outstrip the 6800 Ultra in terms of pure processing power, as well. Memory bandwidth limitations could hold the 7600 GT back somewhat, though. The card's 256MB worth of GDDR3 RAM chips will run at 700MHz, yielding 22.4GB/s. That's well below the level of a 6800 Ultra, but it's a tick more than the Radeon X1600XT and an exact match for the Radeon X800.
However you cut it, the 7600 GT is still an awful lot of video card for $199 to $229, its expected price range. (Some brands may hock 128MB versions for $179, as well, for those who prefer not to have enough memory for their fancy GPUs.)
The GeForce 7600 GT
As you can see, the 7600 GT shares a cooler with its bigger sibling, the 7900 GT. This card doesn't require the help of an auxiliary six-pin power connector, however, and has a somewhat lower TDP of 60 to 70 watts. Like the 7900 cards, NVIDIA expects these babies to be selling at online retailers starting today.
Before we move on, I should mention here that ATI would almost certainly take issue with my direct comparison of the GeForce 7600 GT with the Radeon X1600 XT, despite their apparent similarities in chip size and shader power. The Radeon X1600 XT has made an impressive odyssey in the few short months since its introduction, from a brand-new contender in the mid-range graphics segment listing for $249 to a card with much humbler aspirations selling for as little as $149. The price drops have certainly been welcome, but they've also made the Radeon X1600 XT a moving target for reviewers like us who have been trying to put our fingers on the X1600 XT's most direct competitors. Given what we've seen of its performance to date, the X1600 XT would certainly seem to belong at this lower price point, but ATI's initial aims for the XT were much grander, obviously. Fortunately, ATI has finally moved to plug the gap in the middle of its Radeon lineup caused by the incredible shrinking X1600 XT, as we're about to explain.
