Radeon X1900 XT/XTX: The Battle for Watts
Power consumption is by far not the least important of a modern graphics card’s parameters, so each new device we receive in our labs has to pass an appropriate test. The appetite of the Radeon X1900 XT was measured on a special testbed with the following configuration:
- Intel Pentium 4 560 CPU (3.60GHz, 1MB L2 cache)
- Intel Desktop Board D925XCV
- 2 x 512MB PC4300 DDR2 SDRAM
- Samsung SpinPoint SP1213C hard disk drive (Serial ATA-150, 8MB buffer)
- Microsoft Windows XP Pro SP2, DirectX 9.0c
We measured the power consumption of the card with a digital multimeter Velleman DVM850BL (0.5% measurement accuracy). To put a Peak 3D load on the card we ran the first SM 3.0 graphics test from 3DMark06 in a loop at 1600x1200 resolution and with enabled 4x FSAA and 16 AF. Then we created an extremely high 2D load by launching the 2D Transparent Windows test from Futuremark PCMark05. Here are the results:
The Radeon X1800 XT has been considered the most voracious graphics card up till now, consuming over 110W when running heavy 3D applications. The new Radeon X1900 XT eats up more, but only by a negligible 8 watts, despite its 48 pixel shader processors. The senior model in the series, Radeon X1900 XTX, is going to consume a little more, like 2-4 watts extra, considering the relatively small difference in the clock rates of the two cards. The results also suggest that the graphics processor is not the single heavy consumer on a modern graphics card. We are sure a big portion of those 120 watts falls on the 512 megabytes of high-speed GDDR3 memory, although we don’t have the means to check out this supposition.
Since the Radeon X1900 XT differs but very little from the Radeon X1800 XT in terms of power consumption, the power supply recommendations remain the same. If you want to use a Radeon X1900 XT or XTX, you will need a high-quality 450-500W PSU. And if you are into multiple GPU configurations and want to run two Radeon X1900 cards in CrossFire mode, you will need a 500-550W or better power supply, the same as you would need for a CrossFire system with two Radeon X1800 XT.