SCSI2SD V6 6.0.13 DD performance

03:00.0 LSI Logic / Symbios Logic 53c810 (rev 01)

$ lsscsi
[0:0:1:0]    cd/dvd   SEAGATE           ST225N  6.0  /dev/sr0
[0:0:2:0]    disk     SEAGATE          ST225N   6.0  /dev/sda
$  dd if=/dev/sr0 of=/dev/null bs=1M count=5000 iflag=direct
200+0 records in
200+0 records out
209715200 bytes (210 MB, 200 MiB) copied, 28.2494 s, 7.4 MB/s
$ dd if=/dev/sr0 of=/dev/null bs=512k count=5000 iflag=direct
400+0 records in
400+0 records out
209715200 bytes (210 MB, 200 MiB) copied, 28.3424 s, 7.4 MB/s
$ dd if=/dev/sr0 of=/dev/null bs=128k count=5000 iflag=direct
1600+0 records in
1600+0 records out
209715200 bytes (210 MB, 200 MiB) copied, 30.1954 s, 6.9 MB/s
$ dd if=/dev/sr0 of=/dev/null bs=64k count=5000 iflag=direct
3200+0 records in
3200+0 records out
209715200 bytes (210 MB, 200 MiB) copied, 32.4543 s, 6.5 MB/s
$ dd if=/dev/sr0 of=/dev/null bs=32k count=5000 iflag=direct
5000+0 records in
5000+0 records out
163840000 bytes (164 MB, 156 MiB) copied, 27.6764 s, 5.9 MB/s
$ dd if=/dev/sr0 of=/dev/null bs=16k count=5000 iflag=direct
5000+0 records in
5000+0 records out
81920000 bytes (82 MB, 78 MiB) copied, 16.3973 s, 5.0 MB/s
$ dd if=/dev/sr0 of=/dev/null bs=8k count=5000 iflag=direct
5000+0 records in
5000+0 records out
40960000 bytes (41 MB, 39 MiB) copied, 11.2653 s, 3.6 MB/s
$ dd if=/dev/sr0 of=/dev/null bs=4k count=5000 iflag=direct
5000+0 records in
5000+0 records out
20480000 bytes (20 MB, 20 MiB) copied, 8.23073 s, 2.5 MB/s
$ dd if=/dev/sr0 of=/dev/null bs=2k count=5000 iflag=direct
5000+0 records in
5000+0 records out
10240000 bytes (10 MB, 9.8 MiB) copied, 7.32721 s, 1.4 MB/s
$ dd if=/dev/sr0 of=/dev/null bs=1k count=5000 iflag=direct
5000+0 records in
5000+0 records out
5120000 bytes (5.1 MB, 4.9 MiB) copied, 6.80257 s, 753 kB/s