>What's a TMU?TMU - Texture Mapping Unit, the GPU component responsible for poor performance rendering clouds in the ATI Radeon HD 3800 series.Cheers,- jahman.

>>They fixed the TMU issue with the 3xxx cards which>>is why they were choking to death in heavy weather.>>>You mean they fixed the TMU issue for the 3xxx cards>(driver fix), or only for the 4xxx (hardware fix)?>>Do you have any additional info (e.g. URL)?>>Thanks for the clarification.>>Cheers,>>-jahman.Love answering my own questions...According to THG article "(First Look) AMD/ATI RadeonHD 4870" at (nice preview pics!):http://www.tomshardware.tw/574,news-574.htmlThe ATI Radeon 4800 specs are:Radeon HD Units 4870X2* 4870 4850 3870----------------- -------- ------ ----- ----- -----Transistors million 1,930 965 965 666Process nm 55 55 55 55Stream Processors 1,600 800 800 320Texture Units TMUs 80 40 40 16Render Back-Ends 32 16 16 16Core Clock MHz 750 750 625 775Memory Type GDDR 5 5 3 4Memory Clock MHz 900 900 1,000 1,125Memory Rate Gbps ? 3.6 2.0 2.25Math (+ and x) TeraFLOP 2.4 1.2 1.0 0.497* NOTE: The HD4870X2 specs are my *2x extrapolation* of the 4870 specs!So the improvement in 3870 vs. 4870 cloud handling would bedue to an increase in TMUs from 16 to 40 (a 2.5x increase!)Cheers,jahman.

TMU's are hardware however they can be limited by the manufacturethe 38xx series cards only have 12-16 as I recall and the 4xxx series will have 32

Thanks!