Hi, Write performance on the SD emulation on ARM is rather painful with the default empty SD_OPTS; it's getting something like 130KB/s on the vexpress model With cache=writeback this goes up to a sensible 8MB/s. (This is with the file on an LUKS encrypted lvm partition that is my home directory on an Ubuntu Lucid install on my core 2 laptop).
The impact is probably so bad because most of the writes are done using the SD card's native 512byte block size which turns into a read/modify/write. Is it reasonable to set SD_OPTS to "cache=writeback" ? If people want other options they can always use -drive, but having the default give 130KB/s is nasty. Dave
