The core clock frequency has been lowered from 1GHz to 860MHz which has reduced the compute performance from 2.56 TFLOPS to 1.75 TFLOPS, a 32% reduction. At 860MHz the new Radeon HD 7850 is clocked 4% slower than the HD 6870 and 11% higher than the HD 6850. The GDDR5 memory still works at 1.2GHz, which is effectively 4.8GHz DDR. Because the memory bus is still 256-bit wide the bandwidth remains at an impressive 153.6GB/s, which is 20% greater than the old HD 6850.
AMD has also kept the card’s capacity at 2GB which is the same amount of memory that can be found on the older Radeon HD 6970 and HD 6950 graphics cards.
Where the Radeon HD 7850 really differs from its bigger brother is in the core configuration. The HD 7850 has been downgraded to include 1024 SPUs and 64 TAUs (down from 1280/80), while the ROPs remain at 32. At least on this reference board, the Radeon HD 7850 uses the exact same cooler as the HD 7870. Note however that the Radeon HD 7850 lowers its load consumption to 130 watts, 26% less than the HD 7870.
The Radeon HD 7850 is a PCI Express 3.0-compatible graphics card just like the HD 7870. The HD 7850 doesn’t require but a single 6-pin PCIe power connector. This means Crossfire setups only need a pair of 6-pin PCIe connectors from the PSU, which is a very mild requirement. Finally the same I/O panel configuration has been used: a dual DL-DVI connector, a single HDMI 1.4a port and two mini-DisplayPort 1.2 sockets. All HD 7850 graphics cards support a max resolution of 2560x1600 on up to three monitors. With a multi-stream hub using the mini-DisplayPort 1.2 sockets, the card can power up to six screens.
