Hello, Recently I have been playing with newewst dd version and noticed that "direct" flag gives huge speed boost ( 2x-3x) when accessing raw hdd. I attributed it to bufer layer cpu overhead but on 10x faster CPU boost is the same. What is more, on head movement heavy IO load (dd'ing beeteween different disk places) transfer is also 2x faster.
What is the problem with my system. Is my system badly misconfigured? Best regards, DS. ps Please cc to [EMAIL PROTECTED], thanks. dd if=/dev/hdc of=/dev/null bs=1M count=100 skip=600 100+0 records in 100+0 records out 104857600 bytes (105 MB) copied, 7.10541 seconds, 14.8 MB/s dd if=/dev/hdc of=/dev/null bs=1M count=100 skip=600 iflag=direct 100+0 records in 100+0 records out 104857600 bytes (105 MB) copied, 2.87005 seconds, 36.5 MB/s dd if=/dev/hdc of=/dev/null bs=1M count=100 skip=600 iflag=direct 100+0 records in 100+0 records out 104857600 bytes (105 MB) copied, 2.69986 seconds, 38.8 MB/s _______________________________________________ Bug-coreutils mailing list [email protected] http://lists.gnu.org/mailman/listinfo/bug-coreutils
