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AMD launch the ‘Pitcairn' series of graphics cards today, completing their Trinity of new Direct X 11 discrete solutions. In previous months we analysed the ‘Tahiti' series HD7970 /HD7950 and the ‘Cape Verde' HD7770 and HD7750, targeting the ultra high and lower end price points respectively. The HD7870 and HD7850 are released to fill out the middle ground, aimed at the enthusiast user who wants plenty of bang for the buck.
AMD have thrown the discrete graphics market into turmoil this year with so many models available that the consumer has been left scratching his or her head in confusion. Which card to get if you want to play demanding games on an affordable 24 inch screen? Do you really need to cause serious injury to your credit card by picking up a HD7950? Is it really wise to spend your money on a last generation card such as the HD6950?
A quick look at the market right now is in order.
AMD's HD7970 and HD7950 are without question two of the fastest video cards on the market, but sadly for most people they remain a pipedream, just out of financial reach. The HD7950 is retailing around £360 inc vat and the HD7970 is still priced around £460 inc vat. It would be fair to say that the audience for either card will be small. The HD7770 and HD7750 on the other hand are reasonably priced between £85 and £130 inc vat, but they lack the grunt to attract the hardcore gaming enthusiast. There is currently a gaping hole in the market between £200 and £300 for AMD to fill.
Gamers have been waiting on a price point replacement for the HD6950 and HD6970, the last generation flagship models which span the gamut between £200 and £300. They will be addressing this problem today, a couple of months after the HD7970 was launched.
AMD have a lot riding on the success of the HD7870 and HD7850. History has indicated that the series of hardware just below the flagship models often deliver amazing performance without the hefty price premium. The AMD HD6950 for instance proved incredibly popular, thanks in part to the fact that some could be flashed to the same specifications as the more expensive HD6970.
So are the HD7850 and HD7870 going to satisfy the demanding enthusiast?
Product | AMD HD7970 | AMD HD7950 | AMD HD7870 | AMD HD7850 |
Core Clock speed | 925mhz | 800mhz | 1000mhz | 860mhz |
Transistors | 4.31 billion | 4.31 billion | 2.8 billion | 2.8 billion |
Stream Processors | 2,048 | 1,792 | 1,280 | 1,024 |
Compute Performance | 3.79 TFLOPS | 2.87 TFLOPS | 2.56 TFLOPS | 1.76 TFLOPS |
Texture Units | 128 | 112 | 80 | 64 |
Texture Fillrate | 118.4 GT/s | 89.6 GT/s | 80 GT/s | 55.0 GT/s |
ROPs | 32 | 32 | 32 | 32 |
Pixel Fillrate | 29.6 GP/s | 25.6 GP/s | 32.0 GP/s | 27.52 GP/s |
Z/Stencil | 128 | 128 | 128 | 128 |
Memory Type | 3GB GDDR5 | 3GB GDDR5 | 2GB GDDR5 | 2GB GDDR5 |
Memory Clock | 1,375mhz | 1,250mhz | 1,200mhz | 1,200mhz |
Memory Data Rate | 5.5 GBps | 5.0 Gbps | 4.8 Gbps | 4.8 Gbps |
Memory Bandwidth | 264 GB/s | 240 GB/s | 153.6 GB/s | 153.6 GB/s |
Above, we have a graph showing the technical specifications of the Tahiti and Pitcairn cards. Both HD7870 and HD7850 are built around 2.8 billion transistors, down from the staggering 4.31 billion on both HD7970 and HD7950 designs. The HD7870 is shipped with a very high core clock of 1 GHZ and the HD7850 is downclocked to 860mhz. We will expect AMD partners to ignore these reference clock speeds with upcoming custom overclocked versions. But that is for another day.