It’s easy to tell which animal is faster, a tortoise or a cheetah, a hawk or a swallow, but if you delve deeper into the matter, you will find out that each animal is just as fast as is expected basing on the laws of survival and evolution.
In a similar way, PC component manufacturers are turning out various different products to match every market niche and every usage scenario. While we’re routinely reporting to you on new speed records set by high-performance products from AMD and Nvidia, we’ve been somewhat neglecting the entry-level market segment. We are going to make our amends in this review and cover graphics cards which are not fast because they are just not meant to be such.
Caicos and Turks: Family Portrait
A year ago we tested three entry-level graphics cards from AMD in our review ATI Radeon HD 5670, Radeon HD 5570 and Radeon HD 5450: A Multimedia Ideal? and now we’ve got a new trio which includes Radeon HD 6670, 6570 and 6450. The transition to the newer generation has brought about a number of changes, both big and small, but the architecture of the Turks and Caicos chips has not changed fundamentally. These GPUs still use VLIW5 stream processors to execute instructions.
The Radeon HD 6670 and HD 6570 cards are based on the Turks GPU which incorporates 716 million transistors, is manufactured on TSMC's 40nm facilities and has a die size of 118 sq. mm (compare this to the 104 sq. mm and 627 million transistors of its predecessor codenamed Redwood). AMD managed to pack as many as 480 ALUs into this chip. The junior Turks (the 6570 model) differs from the senior one (the 6670 model) in its TPU count (16 against 24) and clock rate (650 against 800 MHz).
Compared to the previous GPU of the same class, the new ones have grown by about 10% in terms of the transistor count and chip size. Unfortunately, power consumption has increased, too. Of course, a TDP of 50-60 watts cannot surprise anyone today when there exist graphics cards consuming over 300 watts, yet this is 20% higher than the power consumption of the previous series. This may also affect the noisiness of the cooling system, which is an important factor for HTPC-oriented graphics cards.
The Radeon HD 6450 has also grown up compared to its predecessor Radeon HD 5450 and incorporates as many as 160 ALUs clocked at 750 MHz. There is an appropriate increase in power consumption: from 19 watts to 31 watts.
Although the Caicos and Turks GPUs have not acquired new stream processors or DirectX 11+ features, they can boast the most advanced display controller available as well as Universal Video Decoder 3.0 with official stereo 3D support.
Like the rest of the Northern Islands family chips, the new GPUs support DisplayPort 1.2 (it implements the 120 Hz refresh rate necessary for stereo 3D monitors), HDMI 1.4a, dual-link DVI-I and D-Sub. Eyefinity technology enables the Radeon HD 6400/6500/6600 series cards to output the picture to four monitors simultaneously (of course, it is possible to use monitors with different interfaces and native resolutions).
The UVD 3.0 video-processor is present in its full-featured form in both the Caicos and the Turks. Thus, the Radeon HD 6400/6500/6600 cards offer hardware decoding support for such formats as MPEG2, DivX/XviD, VC-1, MPEG4-AVC, MPEG4-MVC, and Adobe Flash 10.1 or higher. Blu-ray 3D can be played back thanks to hardware MPEG4-MVC acceleration which was missing in the Radeon HD 5000 Evergreen family.
Like their predecessors, the Radeon HD 6400/6500/6600 cards support Protected Audio Path and can bitstream 7.1 audio (192 kHz/24 bits per sample) with a bit rate up to 6.144 Mbps in AC3, DTS, Dolby True HD, DTS HD/DTS HD Master Audio, LPCM (Linear Pulse Code Modulation) and other advanced formats via HDMI 1.4a for an external receiver to decode.
The video decoding and display controller functionality, coupled with modest power consumption, can make Caicos- and Turks-based products a good choice for HTPCs. We’ll check out if they are indeed suitable for the job shortly.