While Fusion accelerated processing units have featured advanced graphics cores for years, it had been constrained by poor memory bandwidth.
X-bit thinks that the next-generation high-performance APU, code-named Kaveri, will feature a 128-bit GDDR5 memory controller which will sort this out completely.
Apparently the AMD Fusion A-series APU will feature up to four Steamroller high-performance x86 general-purpose cores as well as GCN architecture-based AMD Radeon HD 7000 graphics engine.
This is not bad in itself, but the 128-bit memory controller, which will support both DDR3 as well as GDDR5 memory, should give the chip some real bite.
X-bit said that if the rumours are true then it enables very high performance of integrated graphics sub-system for all-in-one and mobile systems.
However, there are some problems with GDDR5 memory. It needs a point-to-point interconnection and the maximum capacity of today's GDDR5 chips is 2Gb (256MB).
The interconnection problem means that AMD A-series Kaveri APUs with GDDR5 memory will need to be soldered to mainboards which kills off any possible upgrades. The maximum capacity issue means that AMD Kaveri-based system will be equipped with a maximum of 4GB of GDDR5 which is not enough for modern general purpose PCs, or AMD and its partners will have to wait till 4Gb GDDR5 chips arrive.
AMD will probably release its Kaveri APUs in late 2013. So far it is keeping quiet about the rumours.