I was trying to measure the bandwidth for the data transfers on AMD Fusion A8-3850 and I though that because of the absence of the discrete GPU, there is no cost of PCIe. So I was expecting to have very high bandwidth as compared to the numbers on a discrete GPU device. But I got these numbers for the fusion
pinned: H_to_D (4.9GB/s) D_to_D (16GB/s)
page-able: H_to_D (3.8GB/s) D_to_D (16GB/s)
and these one for the NVIDIA GPU
pinned: H_to_D (5.5GB/s) D_to_D (20GB/s)
page-able: H_to_D (4.1GB/s) D_to_D (20GB/s)
Is my understanding wrong or am I missing something here??