On 02/20/2010 07:28 AM, Benjamin S. wrote:
Hello list, I have a Super Talent Ultradrive GX MLC 64GB SSD and an Intel DH55HC board with H55 chipset. Processor is an Intel Core i5-661. Since 2.6.32 the sequentiell read performance of the ssd is bad: # dd if=/dev/sda of=/dev/zero bs=1M count=300 300+0 records in 300+0 records out 314572800 bytes (315 MB) copied, 4.61777 s, 68.1 MB/s Same results with other blocksizes (e.g tested with 4K). With 2.6.31.7 the same hardware is able to read with about 190MB/s. The normal hard drive reads with both kernel versions with about 100MB/s. Does somebody have an idea what I can test before I have to bisect it?
Could be some kind of block layer or IO scheduler behavior change.. you could try testing after doing:
echo noop > /sys/block/sda/queue/scheduler or echo deadline > /sys/block/sda/queue/scheduler and see if that affects the speed.. -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
