With the launch of the XPress 3200, ATI raised questions about the efficiency of NVIDIA's dual chip SLI X16 soluiton and we set to out answer them as best we could.
The Accusation
Just before the RD580 launch on the first of March, ATI came to the media with some claims about NVIDIA?s X16 chipset and how it was much less efficient than ATI?s own competing architecture. It was said that the connection between the two GPUs was in fact much less than the full x16 PCIe speeds that ATI?s chipset had and that this would mean a less than optimal performance scenario for the end user. ATI provided some data from internal testing they had done that indicated NVIDIA?s bandwidth for communication over the NF4 SLI X16 inter-GPU connection was only around 1500 MB/s compared to ATI?s 2500 MB/s.
PC Perspective
The Accusation
Just before the RD580 launch on the first of March, ATI came to the media with some claims about NVIDIA?s X16 chipset and how it was much less efficient than ATI?s own competing architecture. It was said that the connection between the two GPUs was in fact much less than the full x16 PCIe speeds that ATI?s chipset had and that this would mean a less than optimal performance scenario for the end user. ATI provided some data from internal testing they had done that indicated NVIDIA?s bandwidth for communication over the NF4 SLI X16 inter-GPU connection was only around 1500 MB/s compared to ATI?s 2500 MB/s.
PC Perspective
