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One of the challenges with 3D graphics card testing is that every time a new card--or even a new driver--comes out, all of our previous test scores go out the window. Our new monthly graphics card explainer should help you make sense of the ever-changing market.
By Rich Brown (October 27, 2004) |
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One thing we can say about covering graphics cards: it's never boring. The next latest-and-greatest product release from ATI and Nvidia is always right around the corner, and the steady influx of new, more powerful games--Doom 3, Far Cry, and next month's Half-Life 2 highlight this year's list--and driver updates call for constant retesting. And earlier this year, the graphics card space received a jolt, with the introduction of an entirely new graphics card interface: PCI Express (PCIe).
PCI Express: life in the fast lane When we spotted our first motherboard with a PCI Express slot earlier this year, it didn't just usher in a new generation of graphics cards--it also marked the most revolutionary development in PC graphics in nearly a decade. This new technology not only adds another lane to the highway, it also raises the speed limit, leaving the older AGP interface looking like a worn dirt road. The typical 8X AGP motherboard expansion slot limits you to 2 gigabits per second (Gbps) total throughput, which because of the serial design of the AGP bus (as opposed to PCI and PCIe's parallel architecture) means alternating between receiving incoming data and sending outgoing data; it can't do both at once. The new x16 (pronounced "by sixteen") PCIe slot instead uses two channels, one for incoming data and another for outgoing--both rated for 4Gbps. The wider downstream path will allow for better-looking games by giving designers room for more image data, and the 4Gbps upstream is a boon to PC-video enthusiasts because it gives them the ability to edit high-definition video in real time. Looking for an onramp You'll have to do some hunting, however, to find a PCIe graphics card. You'll also need to buy a new PC with an x16 PCIe slot--or rebuild your current system from the motherboard up. Since most AGP-to-PCIe converts will need to purchase an entirely new computer, most graphics card vendors are selling their PCIe cards through system builders. You can find some PCIe cards for sale individually, but most use last generation's graphics processing units (GPUs) ported over to the new interface, the result of ATI and Nvidia rushing to ready their first PCIe offerings. Using retrofitted parts is no way to break in a new technology, and fortunately, both ATI and Nvidia have just launched PCIe cards that boast new GPUs in addition to the PCIe interface. Check out our coverage of the Nvidia GeForce 6600 GT and the ATI Radeon X700 XT for the complete picture. Early returns show that in terms of performance, the two cards are almost identical. High-end PCIe Radeon X800 and GeForce 6800 Ultra cards have been available in prebuilt computers for a few months, but at the moment, it's next to impossible to find them sold à la carte. That shouldn't last for long; we expect PCIe cards with top-of-the-line GPUs to hit retail by the end of 2004. Putting a price on that frame rate Despite the dawn of this new interface, we don't expect AGP cards to go away for at least a year. Both ATI and Nvidia have said that they will release AGP versions of all of their new chips, from the budget cards on up to the midrange, although for now they have rolled out only the higher-end AGP products. Plus, you'll need a completely new system to make the move from AGP to PCIe. If you are looking for a simple graphics upgrade for your current system in the meantime, we've devised a price-to-performance rating that lets you know which of the current AGP chips on the market delivers the best frame rate for your gaming dollar. For example, our reviews of the BFG GeForce 6800 GT OC and the eVGA e-GeForce 6800 GT delve into features such as factory overclocking and the software bundle, but our new price-to-performance rating looks at only the performance of the core graphics processor, which the BFG and eVGA cards share. To arrive at the price-to-performance rating, we divided the weighted geometric mean of each GPU's latest benchmark results by the manufacturer's suggested retail price for the respective graphics cards. We use a geometric mean over a standard arithmetic average calculation because the former is a more accurate way of comparing weighted numbers. Price-performance ratings (Higher scores are better)
Our price vs. performance experiment leads us to the clear conclusion that cards based on Nvidia's GeForce 6800 GT chip offer the best frame-rate-to-dollar value of the current crop of high-end AGP graphics cards. Of course, if all you care about is achieving the highest frame rates regardless of the cost, please refer to our consolidated 3D performance chart below. Doom 3 and Far Cry Results (in fps) (Longer bars indicate better performance)
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ATI Radeon X700 XT
ATI's new midrange card offers affordable 3D gaming, but we think it should deliver a little more punch. |
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BFG GeForce 6800 GT OC
BFG's overclocked Nvidia cards don't exactly shatter records, but at least the price tag doesn't hurt. |
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BFG GeForce 6800 Ultra OC
This highest-end, overclocked Nvidia card surpasses the standard version, but it still can't overtake ATI. |
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Nvidia GeForce 6600 GT First Take
Our first look at Nvidia's new GeForce 6600 GT puts it on a par with ATI's Radeon X700 XT: midrange price, midlevel performance. |