A question to the SATA RAID Experts:
We measured the throughput for an INTEL SCRS28X SATA RAID controller with a few SATA II drives and determined, that we realize a data throughput (all cache modes disabled -> write through) from about 0.2 upt ro 0.8 MBit/s. The same drives connected to the onboad RAID controller results up to max 3 MB/s (also cache disabled). This happens also in modes without any RAID. Which cache mode enabled, the drives have a expected throughput from about 60 MBit/s on both controllers.
Does somebody have an explanation for me, why the throughput is such poor if caching is disabled?
We measured with benchmarking tools, but also if you just copy a file around, you "feel" the poor performance.