Stefan Mileschin

Last but certainly not the lesser of the Southern Islands GPU family, AMD has released its Pitcairn-based graphics chips, the Radeon HD 7850 and HD 7870, filling in with some solid brick and mortar products in the mid-to-high performance range.

AMD is checking-off the final boxes in its 28nm foray with two new entries at the $350 and $250 price points, meeting Nvidia on the shelf somewhere between the GTX 570 and the GTX 580.

The chips will fill in the gap between Cape Verde and Tahiti. This particular Pitcairn die counting 2.8 billion transistors and both cards, of course, use the ‘Graphics Core Next’ marchitecture whose glories AMD has been trumpeting since last December.

Looking at what AMD has been doing with the architecture on this level, we can see that it has avoided some pitfalls like increasing the cost of components.

The HD Radeon 7870 clocks in at a flat 1GHz, carries 2GB of 4.8GHz GDDR5 and a 256-bit wide memory bus. Its 1280 ‘Streaming processors’ can churn out 2.56TFlops of raw processing power and the card generates 190W maximum TDP.

Its smaller brother, the HD Radeon 7850, clocks in a bit slower at 860MHz, and carries 256 less streaming processors, for a total of 1024. It can process 2.23TFlops of data.

The Radeon HD 7870 apparently performs the same as a GTX 580, undercutting the price by a wide $100 margin, while the HD 7850 will outclass a GTX 570 and still save you $80 or so. The Radeon HD 7870 and 7850 seem to excel at idle power usage, from what we have gathered but are fairly meek when it comes to double-precision floating point operations. In fact, despite the pricing difference, an equally-clocked GTX 580 or GTX 570 would wipe the floor with either.

While the performance on these cards is expected, it’s the pricing that will put the pressure on Nvidia, at least until Kepler hits the market.

http://news.techeye.net/hardware/amd...n-hd-7850-7870