The year 2005 was probably not one of ATI's finest as they were beset with numerous issues, many of which could be traced back to the late introduction of R520, and many of the subsequent parts based on it. However, as 2006 begins, they appear to be attempting to start things more on the right footing. Despite the fact that it was only 3 months ago that ATI released their high end X1800 XT, based on the belated R520 chip, ATI are already announcing its successor with a new range of board: the Radeon X1900 series.

Had we gone by the history of ATI's product refreshes we'd be forgiven for thinking that this would be little more than a slightly warmed over R520 chip, tweaked to yield at higher clock speeds. However, roadmaps leaked sometime ago, with curious configuration indicators would suggest that this wasn't the case for R580. The roadmaps indicated a configuration of 16-1-1-1 for R520 and 16-1-3-1 for R580. It wasn't until RV530 (Radeon X1600) was fully understood did these descriptions become clearer as to their intent; with a configuration signalled on the roadmap as 4-1-3-2 for RV530 it become clear that the numbers represented the number of "pipelines" (even though ATI's engineering didn't like this terminology), the number of texture units per pipeline, parallel shader ALUs per pipeline and the number of Z samples per pipeline. When extrapolated back to R580 it would appear to mean that the pixel shader pipelines would be increased threefold over R520, sounding a little absurd to some...

In this article we'll take a closer look at the R580 architecture and the performance of the high end Radeon X1900 XTX board in single and Crossfire mode.

Product Updates

As is usually the case when a new chip is produced, X1900 will appear in a number of variations. These are the product SKU's that ATI are announcing from the outset of the X1900 launch:

R580-based SKUs

  Core clock  Memory clock  Memory quantity  MSRP 
Radeon X1900 XTX  650MHz  775MHz  512MiB  $649 
Radeon X1900 XT  625MHz  725MHz  512MiB  $549 
Radeon X1900 Crossfire  625MHz  725MHz  512MiB  $599 
All-In-Wonder X1900  500MHz  480MHz  256MiB  $499 

The familiar "XT" SKU is there, however this is not the highest end version, with there now being an "XTX" product existing which has a small 25MHz core clock advantage and 50MHz greater memory speed. What is evident is that as the performance scales ever further upwards, which in this case is by virtue of a larger die size, so too does the price. Here the X1900 XTX reaches a suggested introduction price of $649, which is $100 above the suggested price on X1800 XT's introduction. There also appears to be some curious pricing between the XT and XTX with a $100 difference, yet fairly small clock variations.

The master/slave configuration is still required for X1900 Crossfire, so there is a Crossfire Edition master board announced, however this exists at the same clocks as the XT SKU, suggesting that those who may be considering a Crossfire based system may well be better off in terms of price/performance getting the XT as a slave board rather than the XTX. The price of the Crossfire Edition nestles between the XT's and XTX's pricing, despite its configuration matching the XT, due to the inclusion of the extra components required for the Crossfire compositing engine.

ATI's All-In-Wonder products have often seen a delay from a new graphics chip being released to an All-In-Wonder variant based off it being introduced, however on this occasion, possibly assisted by the pin-to-pin compatibility with R520 and an All-In-Wonder X1800 XL already shipping, an All-In-Wonder version of X1900 should appear within a few weeks of the standard Radeon boards shipping.

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Click for a bigger version

The new X1900 boards sit atop ATI's current range, however this does have some ramifications on parts of the rest of the line-up. Below is a list of the rest of ATI's current desktop range, following the introduction of X1900, and the prices they are now suggested at:

Radeon Desktop Range

  Core clock  Memory clock  Memory quantity  MSRP 
Radeon X1800 XT  625MHz  750MHz  512MiB  $499 
Radeon X1800 XT  625MHz  750MHz  256MiB  $399 
Radeon X1800 XL  500MHz  500MHz  256MiB  $299 
All-In-Wonder 2006  445MHz  400MHz  256MiB  $179 
Radeon X1600 XT  590MHz  700MHz  $169 
Radeon X1600 PRO  500MHz  340MHz  $129 
Radeon X1300 PRO  600MHz  400MHz  $109 
Radeon X1300  450MHz  250MHz  $99 
Radeon X300 HyperMemory  $49 

As we can see, the primary impact the release of X1900 has had is to push the prices of the X1800 series down a little, with the XT's dropping $50, and the X1800 XL dropping to $299 (the introduction price of the X800 XL).

With the announcement of Radeon X1900 ATI are aiming for a simultaneous release of products and the expectation is that boards should be available for purchase now.