nVidia GeForce GTX 580: The Fastest GPU Money Can Buy

GF100 Unleashed

At the chip level, the GeForce GTX 580 is essentially the same as the GTX 480. The new chip that powers it, called GF110, is made using TSMC's 40-nanometer manufacturing process. It's architecturally similar to the GF100, with the same dimensions and the same transistor count. If you were to look at a block diagram of the chip, it would look identical. Features such as cache sizes and the composition of the shader processors are the same. But with the GF110, nVidia fully retooled the chip from the transistor level, fixing many of the problems that make the GF100 hard to manufacture. This enabled the company to release a chip that has all the functional units enabled and yet draws less power and produces less heat than its predecessor. Together with better manufacturing and an enhanced cooling system, the GTX 580 runs the GF110 chip at a somewhat higher clock speed than the GF100 runs in the GTX 480.

There are no major new technologies in the GF110 GPU. It doesn't have support for new display output types, for instance. Cards will have two dual-link DVI connectors, one mini-HDMI connector, and no DisplayPort. There is no new video decoder unit and no additional render back ends. That's not to say that nVidia didn't take the opportunity of remaking the chip to sneak in a few enhancements.

Cooler and quieter: Reworking the GF110 GPU has permitted nVidia to run it at a roughly 10 percent faster clock speed while drawing less wattage (about 20 watts less, in our tests). This is analogous to when a CPU company like Intel produces a new "stepping" of its CPU: The hardware is functionally identical, but it runs cooler. A new vapor-chamber heat spreader and a quieter fan design allow nVidia to cool the GeForce GTX 580 cards more efficiently and quietly, too.

Full-speed FP16 texture filtering: In the GF100, 16-bit floating point textures, often used in high-dynamic-range lighting, were filtered at half speed. Later chips in the Fermi line--for instance, the GF104 that powers the GeForce GTX 460--made some tweaks to filter these textures at full speed. The tweaks were rolled up into the GF110 GPU.

Faster z-culling: Modern graphics chips have a feature called z-culling. With z-culling in place, the graphics chip checks the depth of each part of an object in a scene to see whether something closer to the camera obscures it. If so, the chip rejects that part of the object so that it doesn't have to do all the work necessary to draw it--you can't see it anyway. This hardware is slightly improved in the GF110.

Power draw safeguard: The GF100 and nearly every nVidia card made to date will run as fast as possible when it's in use; and the power draw, heat output, and cooling setups are all geared toward a worst-case scenario in which the GPU is being worked extremely hard. In rare conditions, a GPU may be asked to do too much, may get crazy hot, and may draw too much power from the PCIe power plugs. A perfect example of such conditions is the synthetic FurMark test, which made nVidia graphics cards run unusually hot and draw far more power than they were designed to. A few games have simple 3D rendered menu screens that do not impose an artificial cap on frame rate and can similarly cause too much heat and power draw. The GeForce GTX 580 has a new hardware feature that monitors power draw and will limit the GPU if necessary. This protective mechanism won't affect performance in regular game situations, but it could affect performance on benchmarks like FurMark, and it should keep the card from getting loud and hot in those odd games that have misbehaving menus.

Next: Impressive Performance

Subscribe to the Power Tips Newsletter

Comments