Radeon HD 3000 series

The Unified Video Decoder (UVD) SIP core is present on the dies of the GPUs used in the HD 2400 and the HD 2600 but not of the HD 2900. The HD 2900 introduced the ability to decode video within the 3D engine. This approach also exonerates the CPU from doing these computations, but consumes considerably more electric current.

The Radeon HD 3800 series was based on the codenamed RV670 GPU, packed 666 million transistors on a 55 nm fabrication process and had a die size at 192 mm², with the same 64 shader clusters as the R600 core, but the memory bus width was reduced to 256 bits.

The RV670 GPU is also the base of the FireStream 9170 stream processor, which uses the GPU to perform general purpose floating-point calculations which were done in the CPU previously.

The Radeon HD 3850 and 3870 became available mid-November 2007.

The Radeon HD 3690, which was limited only to the Chinese market where it was named HD 3830, has the same core as the Radeon 3800 series but with only a 128-bit memory controller and 256 MiB of GDDR3 memory. All other hardware specifications are retained.

A further announcement was made that there would be a Radeon HD 3830 variant bearing the same features as Radeon HD 3690, but with a unique device ID that does not allow add-in card partners in China to re-enable the burnt-out portion of the GPU core for more memory bandwidth.[4]

The Radeon HD 3690 was released early February 2008 for the Chinese market only.

Radeon HD 3870 X2

Radeon HD 3870 X2 (codenamed R680) was released on January 28, 2008, featuring 2 RV670 cores with a maximum of 1 GiB GDDR3 SDRAM, targeting the enthusiast market and replacing the Radeon HD 2900 XT. The processor achieved a peak single-precision floating point performance of 1.06 TFLOPS, being the world's first single-PCB graphics product breaking the 1 TFLOP mark.[5]

The Radeon HD 3870 X2 uses the same approach for communications between the two GPU cores as the Sapphire Radeon X1950 Pro Dual and Radeon HD 2600 X2. The GPU cores communicate to each other through an onboard PCI-E switch,[6] providing each core with ×8 (Radeon X1950 Pro Dual) to ×16 (Radeon HD 2600 X2) PCI-E bandwidth and becoming a software CrossFire setup, supporting two extra hardware CrossFire bridges. The Radeon HD 3870 X2 uses PEX8547 PCI-E switch,[7] but each core shares ×16 PCI-E bandwidth. The card only sees one CrossFire bridge being placed onboard and between the cores, thus only allowing one CrossFire bridge to be plugged onto the card.[8]

AMD stated the possibility of supporting 4 Radeon HD 3870 X2 cards, allowing 8 GPUs to be used on several motherboards, including the MSI K9A2 Platinum and Intel D5400XS, because these motherboards have sufficient spaces between PCI-E slots for dual-slot cooler video cards, presumably as a combination of two separate hardware CrossFire setups with a software CrossFire setup bridging the two, but currently with no driver support.[9]

The Radeon HD 3600 series was based on the codenamed RV635 GPU, packed 378 million transistors on 55 nm fabrication process, and had 128-bit memory bus width. The support for HDMI and D-sub ports is also achieved through separate dongles. Beside the DisplayPort implementations, there also exists other display output layouts as dual DVI port or DVI with D-sub display output layout.

The only variant, the Radeon HD 3650, was released on January 23, 2008 and has also an AGP slot with 64-bit bus width or the standard PCI-E slot with 128-bit.

AMD Radeon HD3450

The Radeon HD 3400 series was based on the codenamed RV620 GPU, packed 181 million transistors on a 55 nm fabrication process, and had 64-bit memory bus width. Products were available in full height ATX cards and low-profile cards.[10]

One of the notable features is that the Radeon HD 3400 series (including Mobility Radeon HD 3400 series) video cards support ATI Hybrid Graphics.[11]

The Radeon HD 3450 and Radeon HD 3470 were released on January 23, 2008.

AMD Catalyst is being developed for Microsoft Windows and Linux. As of July 2014, other operating systems are not officially supported. This may be different for the AMD FirePro brand, which is based on identical hardware but features OpenGL-certified graphics device drivers.

AMD Catalyst supports of course all features advertised for the Radeon brand.

The Radeon HD 3000 series has been transitioned to legacy support, where drivers will be updated only to fix bugs instead of being optimized for new applications.[22]

The free and open-source drivers are primarily developed on Linux and for Linux, but have been ported to other operating systems as well. Each driver is composed out of five parts:

1. Linux kernel component DRM
2. Linux kernel component KMS driver: basically the device driver for the display controller
3. user-space component libDRM
4. user-space component in Mesa 3D;
5. a special and distinct 2D graphics device driver for X.Org Server, which is finally about to be replaced by Glamor

The free and open-source "Radeon" graphics driver supports most of the features implemented into the Radeon line of GPUs.[23] They are not reverse engineered, but based on documentation released by AMD.[24]