Rookie_MIB :
^^ What they said.
The bus size is merely the number of physical pathways to transfer data. The more of them there are, the more data can be accessed simultaneously enabling overall a faster data transfer rate. So - given a similar price, having a wider data path enables a faster card.
Stability is another thing entirely. That is determined by the drivers, and that being said if it is a FirePro series card, that means it's a professional usage model card and that means stability is one of the main features. In general FirePro (and Nvidia Quadro) series cards have usually undergone extensive testing to ensure rock-solid stability as opposed to the general consumer cards which have a much more relaxed attitude towards bugs.
So - if it's a FirePro card, the drivers will be rock-solid. If it's a 256bit bus, then it'll be plenty fast.
Got it, but again i doubt the difference in compute performance of both
W5000 have 1.3 TFLOPs single precision and 79.2 GFLOPs double precision floating point performance &
W5100 have 1.43 TFLOPS peak single precision and 89.2 GFLOPS peak double precision floating point performance.
please check the links below for better view...
http://www.amd.com/en-us/products/graphics/workstation/firepro-3d/5000
http://www.amd.com/en-us/products/graphics/workstation/firepro-3d/5100
Both are good, but Let me know which card will perform well for 3dsmax, vray, photoshop, autocad.