Re: [PATCHES] COPY FROM performance improvements

>>
>>>[root(at)pq-slave root]# /sbin/hdparm -tT /dev/sda
>>>
>>>/dev/sda:
>>> Timing buffer-cache reads: 1816 MB in 2.00 seconds = 908.00 MB/sec
>>> Timing buffered disk reads: 26 MB in 3.11 seconds = 8.36 MB/sec
>>>[root(at)pq-slave root]#
>>
>>Can you post the "time dd if=/dev/zero of=bigfile bs=8k count=500000"
>>results? Also do the reverse (read the file) with "time dd if=bigfile
>>of=/dev/null bs=8k".

I didn't see this come across before... here ya go:

time dd if=/dev/zero of=bigfile bs=8k count=500000

500000+0 records in
500000+0 records out

real 1m52.738s
user 0m0.310s
sys 0m36.590s

time dd if=bigfile of=/dev/null bs=8k

time dd if=bigfile of=/dev/null bs=8k
500000+0 records in
500000+0 records out

real 4m38.742s
user 0m0.320s
sys 0m27.870s

FYI on your hardware raid comment... I easily get 50 megs a second on my
3ware controllers and faster on my LSI SATA controllers.

Sincerely,

Joshua D. Drake

>
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