CPU Usage was 50% over 1 Core and latest Nightly was used
I’d love to see the CPU usage come down and speed go up (it’s a Samsung PM981 and under Windows does 3.5GB/s with less than 10% CPU usage on this system)
Are you using the same block size as the benchmark on windows? That has a significant impact on sequential speed. As the larger block sizes mitigate overhead.
Yes, most of the overhead is probably the allocator calls, we could certainly trim those down, but for now it’s not a priority – most of this overhead occurs on dd only, as for in-kernel read requests an integer multiple of the device block size, which the kernel file cache and thus BFS always do, we use the passed buffers directly.
Try running the test with only 1GB of data… it will probably be much faster as the SSD is probably thermal throttling, also I wouldn’t copy over my SSD like that unless I wanted it to fail sooner. The PM981 is rated for 150TBW (though most drives will exceed this amount before uncorrectable errors prevent it from working).