Originally Posted by Mygaffer
I will be shocked if they release a card with a 512bit memory bus. That is just too much die space taken up and completely unnecessary with the fast GDDR5 memory being used today. Likely 256-bit with 4GB of ram and very fast GDDR5. Since their current designs are not memory bandwidth constrained that makes the most sense, as they will have more die space for more SPs.
I have seen this said to many times now.....
It make no sense at all, or you don't know what your talking about.
Its extremely unlikely that AMD will be downgrading the 384Bit Bus to a 256bit Bus as memory bandwidth accounts a significant proportion of 'any GPU' performance.
For example, it is for exactly that reason the 192Bit GTX 660TI was slower than the 256Bit GTX 670 despite them having exactly the same number of SP's.
Its the reason the 256Bit GTX 760 is faster than the 660TI despite having less SP's....
Same with the Tahiti based 7870's which have a 256Bit Bus and about 15% less SP's than the 7950 and yet clock for clock are still a solid 25% slower.
Another way to put it, overclock your memory, watch what happens to the performance of your GPU.
Its not rocket science.
The Top end AMD GPU's Will
remain 384Bit. if anything the 7870's replacement might also get a 384Bit Bus.