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ATI Radeon HD 2900 XT

ATI’s DirectX 10 capable GPU is finally here in the form of the Radeon HD 2900 XT. Does this $399 video card have what it takes to compete with NVIDIA’s 8800 series? We explore the architecture, image quality, and real world gaming that shows a different experience than canned benchmarks.

Introduction

The day we have been waiting for is finally here; ATI is announcing the “600” family of GPUs. While the entire 600 family is being announced today only one video card from that family will actually be available today, and that is the one we are evaluating. Let’s take a quick step back and recap the state of GPU affairs.

For the past six months NVIDIA has been leading in performance and features with the GeForce 8 series (G80). The GeForce 8800 GTX and 8800 GTS were announced and launched on November, 8th 2006. These two video cards shocked the hardware community with an unprecedented leap in 3D performance from the previous generation GPUs. We experienced something which was quite extraordinary, the ability to run every current game at the highest possible in-game settings at high resolutions with high levels of AA.

NVIDIA further extended this lineup three months ago by bringing GeForce 8800 GTS levels of performance down to a more affordable price with the 320 MB version. In fact these video cards can be found for as low as $259.99 online today with rebate. NVIDIA did not stop there though, a month ago they released their mainstream lineup, the GeForce 8500 GT, 8600 GT and 8600 GTS offering the best performance in that class. Even that wasn’t the end though; only two weeks ago NVIDIA launched the GeForce 8800 Ultra, though to an ill-receiving audience. Quite simply the GeForce 8800 Ultra is overpriced for the performance increase over the GeForce 8800 GTX. All this time ATI was quiet.

We have been living off of the Radeon X1000 architecture now for a very long time; 18 months. The ATI Radeon X1000 family was announced on October 5th, 2005 but we did not see the Radeon X1800 XT until a month later in November of 2005. The ATI Radeon X1800 XT (and X1K family itself) interestingly, like the R600, was also late to the party. The Radeon X1800 XT performed well in games and was quickly usurped by the Radeon X1900 series launched in January of 2006. It is the Radeon X1900 series we have seen many GPUs spun off of, such as the Radeon X1950 XT/X and Radeon X1950 Pro; all very popular video cards. In the past six months the X1000 family has been completely annihilated by the GeForce 8 series in games. In fact, we found it rather pointless to even include them in evaluations because we know the GeForce 8 GPU equivalents would wallop them quite easily.

It has been a long wait, but ATI’s next generation DirectX 10 GPU is finally here to compete with the GeForce 8 series.

ATI Radeon HD 2000 Series

On this page we will lay out the models being announced on the desktop side. On the next page you will find pictures of the one being launched and evaluated. On the following pages we will go into detail on the architecture, if you wish to skip straight to Radeon HD 2900 XT gaming, that starts on page 8.

Gone is the “X” in front of the model number on ATI’s new GPUs. For this generation that “X” has been replaced by an “HD” for “High Definition.” ATI is announcing the value end Radeon HD 2400 Pro and Radeon HD 2400 XT. In the mainstream you will find the Radeon HD 2600 Pro and Radeon HD 2600 XT. At the high-end is the Radeon HD 2900 XT. The entire Radeon HD 2000 series supports DirectX 10 and Shader Model 4.0 and is based on a unified shader architecture.

Radeon HD 2900 XT

At the high-end the Radeon HD 2900 XT is based off of an ATI and TSMC proprietary 80nm HS processes and contains 700 million transistors. The Radeon HD 2900 XT will have 320 stream processing units and carry a core clock speed of 740 (742.7 MHz actual). Note that there are not separate clock domains; the streaming processors and the core (texture units and ROPs) all run at the same speed unlike the G80 which runs the shader processors much faster than everything else.

The texture units and render back-ends (ROPs) are separate units and there are 16 of both on the Radeon HD 2900 XT. There will be 512 MB of GDDR3 on a 512-bit memory bus clocked at 825 MHz (1.65 GHz) on the Radeon HD 2900 XT. This gives us 106 GB/sec of memory bandwidth available. Native CrossFire is back and fully supported with the Radeon HD 2900 XT.

"This sucker's electrical, but I need a nuclear reaction to generate the 1.21 jigawatts of electricity I need" - Doctor Emmett Brown

OK, it isn't that bad, but the quoted power draw is 215W at full load which is the highest power draw from any consumer 3D graphics card. For a single Radeon HD 2900 XT ATI recommends a 550W power supply. For CrossFire a 750W power supply is recommended. Power leakage is a reported problem with this GPU. Different Radeon HD 2900 XT video cards, depending on binning, will have different wattages. So if you purchase two video cards, they could very much be pulling greater or lesser wattages. Ambient temperature fluctuations will also cause differing power utilization, as the temperature increases power draw increases fast.

This video card will be bundled with the Valve Half Life 2 Black Box containing Team Fortress 2, Portal and Half Life 2: Episode 2. Since the Valve Black Box is not out yet the bundles will include a voucher. The entire package will be $399.

ATI Radeon HD 2600 and 2400

The ATI Radeon HD 2600 and 2400 is based on an entirely new and power efficient 65nm processes. They are based on the same architecture as the Radeon HD 2900 XT and simply scale down the number of stream processors, texture units and ROPs. The Radeon HD 2600 is made up of 390 million transistors and will have 120 stream processing units, 8 texture units and 4 ROPs with a core speed of 600-800 MHz depending on the model. The memory configuration will vary depending on the manufacturer; it supports 256 MB of GDDR4, GDDR3 or DDR2. The memory bus is 128-bits wide and will run anywhere from 400-1100 MHz (depending on manufacturer). This will provide anywhere from 12.8-35.2 GB/sec.

The Radeon HD 2400 with 180 million transistors will be scaled down to 40 streaming processor units, 4 texture units and 4 ROPs. It will run anywhere from 525-700 MHz depending on the manufacturer. The memory bus however is quite crippled at 64-bits wide running anywhere from 400-800 MHz.

The exciting feature about the Radeon HD 2600 and 2400 is their low power usage. At full load the quoted power consumption for the Radeon HD 2600 is 45W and with the Radeon HD 2400 it is 25W. In fact it was mentioned that at idle we could single digit wattage numbers on the Radeon HD 2400. Neither the Radeon HD 2400 nor Radeon 2600 require external auxiliary power.

The Radeon HD 2400 will be found for around $99; even less perhaps, it is a passive solution and will support HDMI and AVIVO. The Radeon HD 2600 will be found from $99-$199 and supports native CrossFire.

Availability

Here is the catch. There is only one video card being launched today in the high-end, the Radeon HD 2900 XT at $399 which “competes” with the GeForce 8800 GTS 640MB. Here is a GeForce 8800 GTS 640 MB from PNY that can be had for $329.99 with a rebate which is the lowest we've seen yet. This is as fast as it is going to get for ATI’s current lineup. The Radeon HD 2900 XT is available at online retailers today. The Radeon HD 2600 and 2400 however will not be available until late June. After waiting so long it is sad to see even more delays.