No one reply? Strange. To summarize, Assuming Drivers plays the +- 5% difference in test, an actual GFLOPS output / Bandwidth Performance Numbers actually gives a VERY accurate results of the GPU performance.
But it doesn't take into account the amount of memory with GFX card. With 22nm and 3D Package, Intel could literally stack 64MB of L3 Cache offering ~300GB/s of bandwidth to its iGPU. Of coz since the iGPU has low number of GFlops, it doesn't require that much bandwidth.
But would these excess bandwidth help with the lower amount of memory?