PowerPC systems does not support CPU write combining. The effect of this is that every CPU store will be transmitted to the remote memory as a small PCIe transfer. This will normally have a huge impact on the write performance compared to e.g. an Intel CPU running at the same speed. PowerPC users should use DMA operations to transfer larger amounts of data. The SISCI benchmarks scibench2 and dma_bench can be used to determine the actual system performance. More information can be found in Section 4.2, “SISCI API demo and benchmarks programs”