Review AMD’s Radeon HD 5770 and 5750 are the mid-range members of the new HD 5000 DirectX 11 graphics chip family. They’re fabbed using a 40nm process, just like their bigger brothers.
Sapphire’s HD 5770: reference Radeon HD 5770 design
But the number of transistors in these mid-range chips – codenamed ‘Juniper’ – has been reduced by just over a half, from the 2.15bn in the 58×0 design, codenamed ‘Cypress’, to 1.04bn. The area of the chip has also been quartered, from 334mm² to 166mm².
Armed with that information, you won’t be surprised to learn that the number of unified shaders in 5770 has been halved too. Which is to say that the 5870 has 1600 shaders and the 5770 has 800. The 5750 has 720.
When it comes to clock speeds, the 5770 has the same 850MHz core speed as 5870 while the 5750 runs at 700MHz, which is slightly slower than the 5850′s 725MHz frequency. The specification of the memory breaks with tradition as the junior 5750 and 5770 use 1GB of GDDR 5 just like the grown-up 5850 and 5870. In the past, we’ve been accustomed to mid-range chips that use slower memory than their high-end siblings do. The high-end chips use a 256-bit memory controller while the new mid-rangers settle for a 128-bit controller. Read the rest of this entry »
Review When Sapphire had added its Vapor-X cooler to AMD’s Radeon HD 4850 it turned a standard single-slot board into a very, very quiet dual-slot card. Now it has performed the same trick on the Radeon HD 4890.
Sapphire’s Radeon HD 4890 Vapor-X: very, very quiet…
The two Vapor-X designs look very similar, but there has been a small change made to the new model. The backplane of the 4850 carries DVI, HDMI and VGA outputs, while the 4890 gains a DisplayPort connector. If you have two digital TFT displays connected to your PC, you’ll be grateful to learn that Sapphire now includes an HDMI-to-DVI adapter in the box so dual DVI is an option.
Despite the cosmetic similarities, the 4890 is a more formidable gaming beast than the 4850. Its GPU core is clocked at a higher speed and the use of 1GB of GDDR 5 memory rather than 512MB of GDDR 3 increases the bandwidth substantially. If you fancy paying a £35 premium you can buy Sapphire Vapor-X with a mighty 2GB instead. Read the rest of this entry »
