2 HD5750 Vs 1 HD5850

[Houven]

Which is better for HD video encoding and viewing?
2 HD5750 1G 128 bit cross fire or
1 HD5850 1G 256 bit
Since they cost more or less the same.
Remember ATI claims their video cards' "Streaming" capability helps video encoding.

 

[ViRGE]

AMD's AVIVO video encoding abilities are next to useless. The quality is much too low as it's built for balls-to-the-wall speed rather than any kind of quality/speed balance. Think of it more as a tech demo than a practical tool.

At any rate, any kind of GPU-accelerated video encoder is currently limited to 1 GPU. So a Crossfire/SLI configuration would result in the 2nd GPU being wasted. If you're serious about using AVIVO, then you would want the 5850.

There will be no difference in viewing since it's a low-intensity job that either video card handles just as well.

 

[Houven]

One more question. Is the memory bandwidth (put throught rate) the same for 2 x 128 bit crossfire and 1 x 256 bit?

 

[ViRGE]

Technically it's equivalent if you're at the same clock speeds, however each GPU can only utilize half of that memory bandwidth (since it can only access the chips it's connected to). So it's not completely comparable.

 

[betasub]

As ViRGE said, effective memory bandwdth in crossfire mode is only what a single GPU can access. Likewise my 9800GX2 (2x G92 in SLI) may have been advertised as 512bit interface and 128GB/s bandwidth, but actually it is 256bit per GPU, so effective bandwidth for each GPU is 64GB/s (stock).