On 07/21/2011 01:21 PM, Pádraig Brady wrote:
I'm a little wary of this being too aggressive,
but it does give a noticeable (13%) boost on my new laptop.
Here are the numbers from dd bs=$blksize if=/dev/zero of=/dev/null
blksize system-1 system-2
----------------------------
1024 734 MB/s 1.7 GB/s
2048 1.3 GB/s 3.0 GB/s
4096 2.4 GB/s 5.1 GB/s
8192 3.5 GB/s 7.3 GB/s
16384 3.9 GB/s 9.4 GB/s
32768 5.2 GB/s 9.9 GB/s
65536 5.3 GB/s 11.2 GB/s
131072 5.5 GB/s 11.8 GB/s
262144 5.7 GB/s 11.6 GB/s
524288 5.7 GB/s 11.4 GB/s
1048576 5.8 GB/s 11.4 GB/s
Hmm, I've taken the script from the test, but I'm not
quite sure about the numbers on my system:
$ for i in $(seq 0 10); do bs=$((1024*2**$i)); printf "%7s=" $bs;
src/timeout --foreground -sINT 1 dd bs=$bs if=/dev/zero of=/dev/null
2>&1 | sed -n 's/.* \([0-9.]* [GM]B\/s\)/\1/p' ; done
1024=2.3 GB/s
2048=4.0 GB/s
4096=6.7 GB/s
8192=9.7 GB/s
16384=16.3 GB/s
32768=31.3 GB/s
65536=52.2 GB/s
131072=81.6 GB/s
262144=115 GB/s
524288=141 GB/s
1048576=157 GB/s
I have a "Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz" system.
And I used `src/timeout` from the latest `git pull`.
Berny
