Board analysis

On paper, the Radeon X1900 XT 256MB boasts all the key specs found in the 512MB Radeon X1900 XT board. ATI equips the board with all 48 pixel shaders left intact, and core clock speeds remain the same at 625MHz core/725MHz memory (1,450MHz effective). The one key difference lies in the board’s memory configuration, as the board ships with half the memory found in the Radeon X1900 XT 512MB. With less memory onboard, the card is technically cheaper to produce, although the GPU itself is the same R580 core used in higher-end cards like the Radeon X1900 XT 512MB and X1900 XTX.

Physically, the board is indistinguishable from the Radeon X1900 XT 512MB. As you can see, ATI uses the same heatsink/fan unit previously used for Radeon X1800 XT and X1900 XT/XTX cards, although now Ruby sports a different pose and looks considerably less tan.

Other than the paler Ruby, both cards look similar

X1900 XT 256MB (top) and X1900 GT

The new $300 battle: X1900 XT 256MB vs GeForce 7900 GT

Taking a look at the board design itself ATI’s made no changes to the Radeon X1900 XT 256MB: all the power circuitry used on the X1900 XTX 512MB is also present on the Radeon X1900 XT 256MB. Basically, all ATI’s done is swap out the 512Mbit density modules used on the 512MB Radeon X1900 XT cards with 256Mbit density modules. Like the 512MB Radeon X1900 XT/XTX the modules themselves are officially rated for speeds up to 800MHz, so enthusiasts actually have a little bit of headroom for overclocking.

As far as we can tell, ATI’s made no changes to the way the fan operates on the Radeon X1900 XT 256MB. The temperature thresholds that kick the fan into higher RPMs are carried over intact from previous Radeon X1900 XT cards. This will probably come as a disappointment to many of you (especially considering the redesigned cooler found on the X1950 XTX), as the fan can get pretty loud when it kicks into full gear. Fortunately aftermarket coolers can be purchased for the Radeon X1900 XT 256MB that deliver better cooling performance with lower noise levels. In fact, we just conducted a mini-roundup of several aftermarket fans with prices starting as low as sub-$25 that would be well suited for the Radeon X1900 XT 256MB.

So basically the clock speeds on the Radeon X1900 XT 256MB carry over unchanged, as does the cooling and the way the card’s fan operates. But what kind of performance hit (if any) did we experience with less onboard memory? Let’s find out…