Which is better? 2gb of gddr5 128bit or 1gb of gddr5 256bit?

[DaanDieKooHaan]

For example the Sapphire Radeon HD 5850 1GB Vapor-X vs MSI R7 260 2GB OC.

I have heard talk that the bus width doesn't even matter anymore, but can't think that that's true?

If you can explain fully please do.

Thanks in advance!

 

[Joseph DeGarmo]

R7-260 due to the video memory.

 

[InvalidError]

I have heard talk that the bus width doesn't even matter anymore, but can't think that that's true?

It varies on a case-by-case basis.

Newer GPU architectures tend to be more memory-bandwidth-efficient so you can get about the same performance with half the memory bus width. Nvidia's Maxwell does quite well there.

If you compare the HD5870 against the R7-260X (one notch above the HD5850 and R7-260 you were looking at), you can see they are fairly close in performance, with the R7-260X leading most of the time
http://www.anandtech.com/bench/product/1062?vs=1044