There is a reason ATI could not offer a card to compete to the 7900 GT and it should be explained. The core used for the X1900 series is R580. It is a 48 pixel shader, 16 texture unit chip, and is built using 'quads'. Each of these quads consist of 12 of those pixel shader's and 4 of those textures units, meaning there is four quads in R580. When cores are graded or binned but found they cannot run at the core frequency needed for say, the XTX cards, or found to have a faulty quad, they will be used in other lower end cards.

For example, any core that fails to run at XTX speeds (650MHz) but can run at XT speeds (625MHz) will end up being used to build an X1900 XT card. Obviously when binning for an XTX card the core will have to be capable of much higher than 650MHz, probably 680MHz before being deemed acceptable, and the same would be true of the XT cards (probably binned at 650MHz).

So, the X1900 XT allows ATI to make use of many R580 cores that would otherwise end up in big pit under the desert, but when a full quad is defunct, ATI can disable it completely, creating a 36 pixel shader, 12 texture/ROP core, and this my friends, is exactly what you'll find in the X1900 GT.

It should now be clear why ATI went ahead and released a part that couldn't compete with the 7900 GT, they essentially didn't have much creative influence on the specification, and as found in my X1900 GT review, higher clocks made little difference to its performance.

I should point out at this stage that this is common practice in this industry. Nvidia, AMD, Intel, and all the memory manufactures speed bin. I'll give just one example before we move on - The 7900 GTX and 7900 GT. Any G71 cores that cannot manage 700 MHz but can handle 450 MHz will end up as a 7900 GT. I should also note that demand for the cheaper products usually outstrips the ratio of failed cores, so though these under achieving cores will be out there in the retail channel, most of the time cores that would have been suitable for the 7900 GTX will end up in 7900 GT's.

So this brings us neatly...well not at all neatly in fact, to the card on review today, which just so happen to be a 7900 GT. It's still king kong in the sub £200 sector, and if you're willing to dabble in overclocking you can essentially bring it near to 7900 GTX speeds.

In this review I'll be taking a look at Galaxy's 7900 GT and compare it against both the X1800 XT and X1900 GT. This review will be quite similar to the X1900 GT review as it's almost a reversed review with the focus being on the 7900 GT instead of the X1900 GT, so some information will be copied and pasted.

This particular board from Galaxy is a reference board so the clock speeds stay as Nvidia suggests.

To those in the UK, Galaxy may itch at the back of your mind, you've heard it somewhere before, but can't quite remember where. They are apparently a rather big players in Asia and make a lot of non-reference cards with rather cool features and coolers, but the card i'm reviewing is a no frills reference board. I've been hearing for a few months now that Galaxy is to be pushing harder into the UK market over the next few months but has been having a tough time finding distributors. No doubt the brand Galaxy will become well known in blighty once they do.