Starting with the Radeon HD 4890, this new card is in essence an overclocked Radeon HD 4870 with far greater overclocking abilities. ATI has fine-tuned the RV790 XT core allowing for incredible core frequencies. Although the default core speed of 850MHz is a moderate bump over the 4870, many users are reporting overclocks in the order of 1GHz and beyond, which makes for an interesting update.
The GeForce GTX 275 is also a derivative from an existing product, borrowing its GPU from the GeForce GTX 295, which is a dual-GPU graphics card. The GTX 275 uses a 55nm GPU featuring the same amount of SPUs and TAUs as the more powerful GeForce GTX 285, while only as many ROPs as the GeForce GTX 260. Nvidia has then increased the core and memory frequencies of the GeForce GTX 275 when compared to the dual-GPU GeForce GTX 295.
On paper the GeForce GTX 275 is a lot like the GeForce GTX 285, a graphics card that costs an additional $100. The key difference between these two products, other than the slightly different core configurations, is their memory bus width. The more expensive GeForce GTX 285 gets the 512-bit bus, whereas the GeForce GTX 275 features a 448-bit bus, or about 20% less bandwidth at its disposal.
As luck would have it, the GeForce GTX 275 was not just a quick and easy counter for the Radeon HD 4890, it was the perfect counter. Prior to the launch of these two cards the Radeon HD 4870 and GeForce GTX 260 were already doing battle. The Radeon HD 4890 was meant to outclass both products and conquer the $250 price range but evidently that didn't go as planned.
Today we will put both cards to the test and find out which is faster in a wide range of games using the latest drivers. We will also be looking at their maximum overclocked performance to help you decide which is the best value option for enthusiasts and PC gamers alike.