More importantly: dd is not a benchmarking tool. I can't count how many times people have complained about dd being slow on a distributed filesystem. Well, yeah. When you're writing only one block at a time with no concurrency/parallelism at all, over a network interface that has much higher latency than your disk interface, of course it's slow. When you're using tiny block sizes, as about 80% of these people do, the effect is only magnified. Unless your use case for a distributed system is a single user who doesn't even multitask, use iozone or fio instead.