June 25th was set to be the official release date for the new Radeon HD 4000 series, though due to some retailers selling cards early, the NDA was lifted prematurely and tech sites scrambled to get reviews online. Therefore our first Radeon HD 4850 preview went live on the 19th of June, and although we only had time to throw a few benchmarks at it, a few things were already clear. The Radeon HD 4850 was unquestionably an insane piece of hardware at just $200 US, as it disposed of the much more expensive GeForce 9800 GTX with relative ease.

Since reviewing the Radeon HD 4850 we have seen a number of versions from various manufacturers, while the more powerful, more expensive Radeon HD 4870 has been nowhere to be seen. That was until recently, when VisionTek provided us with our first sample of AMD’s new flagship graphics card. While the MSRP of the Radeon HD 4850 was set at a very low $200 US, do not expect the Radeon HD 4870 to be a $600 US graphics card. Rather this power house is priced at just $299 US, which was the going price of a GeForce 9800 GTX just a few weeks ago.

When you look at the high-end performance market there is the older GeForce 9800 GX2, which currently costs around $450 - $550 US, then there are the GeForce GTX 260 and 280 cards that cost $330 - $380 US and $500 - $650 US respectively. The only other high-end graphics card to sell at $300 US or less is the Radeon HD 3870 X2. Therefore it shall be very interesting to see just how well the Radeon HD 4870 competes in the high-end market segment, particularly given that it costs significantly less than the current high-end GeForce competition.

On paper the Radeon HD 4870 truly is impressive. Featuring a staggering 800 (160x5) SPUs, 40 TAUs and 16 ROPs makes the Radeon HD 4870 quite complex. Compare this to the 320 (64x5) SPUs, 16 TAUs and 16 ROPs of the Radeon HD 3870, and you quickly begin to understand just how impressive this new graphics card really is. The Radeon HD 4870 has a memory bandwidth of 115.2GB/s, while the Radeon HD 3870 was limited to 57.6GB/s of bandwidth.

This huge memory bandwidth is a result of using the latest and greatest GDDR5 memory, which comes clocked at 900MHz (1.8GHz x 2 = 3.6Gbps) while the core operates at 750MHz (1.2TFLOPs of computing power), up from the 625MHz core clock of the Radeon HD 4850. For the most part the Radeon HD 4870 and 4850 graphics cards share the same specifications as the core configurations are identical. However the more expensive Radeon HD 4870 graphics card runs the core much higher, while the GDDR5 memory is significantly faster.

The Radeon HD 4870 still features a 256-bit wide memory bus, while the core has also been built using the 55nm design process. Like the Radeon HD 3000 series the new 4000 series also uses the PCI Express 2.0 bus, though it is compatible with PCIe 1.0 motherboards. Unlike the current GeForce series, the Radeon HD 4000 series offers full support for DirectX 10.1, which could prove to be useful in the future. There will be 1GB and 512MB versions of the Radeon HD 4870, while today’s sample from VisionTek features 512MB of onboard GDDR5 memory.