Sério, tenho essa duvida, os 500MB são mais rápidos ou mais lentos que a memória ram, eu não sei.
Muito mais rápidos que a RAM, sem comparação.
All gaming systems today already have multiple pools of graphics memory – what exists on the GPU and what the system memory has to offer via the PCI Express bus. With the GTX 970 and its 3.5GB/0.5GB division, the OS now has three pools of memory to access and to utilize. Yes, the 0.5GB of memory in the second pool on the GTX 970 cards is slower than the 3.5GB of memory but it is at least 4x as fast as the memory speed available through PCI Express and system memory. The goal for NVIDIA then is that the operating system would utilize the 3.5GB of memory capacity first, then access the 0.5GB and then finally move to the system memory if necessary.
The problem and risk is that this performance difference essentially depends on the heuristics of the OS and its ability to balance the pools effectively, putting data that needs to be used less frequently or in a less latency-dependent fashion in the 0.5GB portion.
Porém mesmo mais rápida não é o suficente. Como esse trecho que mostra que essa porção (de 500 MB) tem latência alta e por isso não pode ser acessada com muita frequência e a gestão depende da heurística e administração desses dois blocos balanceando os mesmos com eficiência.
São muitas coisas envolvidas.
Fonte: http://www.pcper.com/reviews/Graphi...Full-Memory-Structure-and-Limitations-GTX-970