AMD Radeon HD 3850

One step forward, one step back

We were so pleased with the price/performance ratio of AMD’s Radeon HD 3870 that we awarded Asus’s implementation of it a 9 Kick Ass verdict in our January 2008 issue. We’re not nearly as impressed with the gaming performance of the architecture’s cheaper cousin, the Radeon HD 3850.

The two GPUs share many features, including the same number of stream processors (320), the same 256-bit memory interface, and AMD’s Unifi ed Video Decoder (for offl oading all HD-video decoding from the host CPU). Both parts also provide HDCP support on both DVI links, so Blu-ray and HD DVD movies can be displayed on a 30-inch panel at the screen’s native resolution.

And like the 3870, the cheaper 3850 supports PCI Express 2.0, Direct3D 10.1, and Shader Model 4.0 (none of Nvidia’s GPUs support the latter two features, although it will be a long time before this advantage really means anything). But while the 3870 reference design features 512MB of GDDR4 memory and a dual-slot cooler, the 3850 board we received was outfi tted with just 256MB of GDDR3 memory, a singleslot cooler and relatively tame core, and memory clock speeds of 670MHz and 829MHz, respectively.

For gaming, the Radeon HD 3870 was at least competitive with Nvidia’s 8800 GT, but the Radeon HD 3850 is a laggard when it comes to gaming at the native resolution of a 24-inch screen (1920x1200). The frame rates we achieved were roughly half of what we obtained with the 8800 GT. If the 3850 cost half as much as an 8800 GT (average street price: $260), this card would garner a Kick Ass award, but at press time, the average street price for these boards was $190. The extra $70 not only buys a faster GPU, but a frame buffer that’s twice as large. If gaming isn’t your bag, the Radeon 3850 is a fi ne GPU for watching high-defi nition movies. But we prefer videocards that can do it all.

On paper, the Radeon HD 3850 looks remarkably similar to the
Radeon HD 3870, but key differences in clock speeds and memory
render the former a tortoise and the latter a hare.