(11-07-2014, 10:54 AM)NaturalViolence Wrote: This is a bit misleading. While memory bandwidth requirements do go up a bit that's not the main source of framerate drops with efb copy to ram. Even with 50GB/s memory bandwidth many games still encounter a big framerate drop when using efb copy to ram. Even though only a fraction of the memory bandwidth is being used.
It's not just the system memory bandwidth. It also needs a fast CPU to properly "feed" the GPU. AMD GPUs perform much better with a fast CPU. The faster the CPU - the better the performance.
EDIT: Updated the Dolphin GPU stress test with a better one. The previous one was already pretty extreme, but new one is brutal (about 10% more demanding than the previous one) - it represents the worst-case scenario.
The results didn't change much - the 7850 still managed to score over 60fps at 7xIR.
Any GPU that passes this test at a specified IR is guaranteed to run pretty much everything at that IR.