Last week Expreview published specs of the RV775 but according to a new report by FUD Zilla, this chip doesn't exist. The site argues a 55nm RV770 doesn't make sense and that there won't be a faster version of the Radeon HD 4870. There may be another mainstream card, but for the next high-performance cards from ATI you'll have to wait for their first 40nm GPUs.
There is no financial sense to release a slightly updated 55nm chip with a bit better specification to counter Nvidia, and as we said before, the next chip from ATI is 40nm and this should happen in Q2 2009 time. GT200 55nm chip and the new GTX 260 with 216 stream processors and a 180 driver are enough to put a lot of pressure on Radeon HD 48x0 sales, but ATI can now initiate price wars that should help the company get by until the new chip arrives.