According to reports from Nordic Hardware and various rumours that are floating around, AMD is preparing yet another mid-range card that will be based on the well known 40nm Barts GPU, the Radeon HD 6790. According to this naming scheme, the new HD 6790 should end up faster than the Juniper based HD 5700 cards but it will be based on the same design as the Barts flavored HD 6800 series.
The upcoming Radeon HD 6790 should end up with 800 Stream Processors organized in 10 streaming multiprocessor units. This simply means that there will be two blocks of 400 SPs with a dispatch processor for each block.
Bear in mind that the Juniper series HD 5770 also have 800 SPs but they are arranged differently. The Barts LE, as some decided to name it, will feature 32 ROPs, 40 TMUs and a 256-bit memory interface although the amount of memory it will pack is still unknown. The first rumors put this card at 840MHz GPU and 1050MHz (4.2GHz effective) memory clocks, although nothing is carved in stone and clocks can be easily changed. The card should have a 150W TDP and will need two 6-pin PCI-E power connectors.
According to our info, the new Radeon HD 6790 card should have the same price as the Geforce GTX 550 Ti. Performance wise, the Radeon HD 6790 should end up a bit faster than the GTX 550 Ti, at least in some games. The card is scheduled for an official release on April 5th.
Nordichardware.com managed to score a picture of the chip design so you can check it out here.