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Old 02-14-07, 04:26 PM   #6
chunkey
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Join Date: Oct 2004
Posts: 662
Default Re: 2.6.20-rt5 and libata, sata_nv and ncq patch

Quote:
Originally Posted by floogy
Hi,

It seems, that you're right: hd tach claimed to mesure 95 MB average read, but HD Tune measures something like this:
Code:
HD Tune: Maxtor 6Y200M0 Benchmark

Transfer Rate Minimum : 28.1 MB/sec
Transfer Rate Maximum : 55.2 MB/sec
Transfer Rate Average : 44.5 MB/sec
Access Time           : 20.0 ms
Burst Rate            : 102.2 MB/sec
CPU Usage             : 4.0%
It also shows NCQ greyed out for this drive.
So, I think the mainboard or the harddrive doesn't support NCQ.
Code:
$ cat /sys/block/sda/device/queue_depth
1
0 means disabled, then 1 might say, that it's not implemented?
Sorry, your HDD doesn't support NCQ. But NCQ does very little for linear reads/writes since the request are already in a good order.

Quote:
I saw some benchmarks with 75 MB/sec on the net, and thought, that I should reach such throughput (==Transfer Rate Average?) under kernel 2.6.20 .

The Transfer Rate Average is 15 MB/sec higher than on linux though...
50MB/s is fine for a HDD.


just for the records
Code:
dbench -t60 -D /tmp 50procs
dbench version 3.04 - Copyright Andrew Tridgell 1999-2004

Running for 60 seconds with load '/usr/share/dbench/client.txt' and minimum warmup 12 secs
50 clients started
  50       672   351.60 MB/sec  warmup   1 sec
..
  50     29140   489.75 MB/sec  warmup  18 sec
  50     33450   564.12 MB/sec  execute   1 sec
  50     35546   562.91 MB/sec  execute   2 sec
...
  50    177820   670.60 MB/sec  execute  59 sec
  50    180429   670.92 MB/sec  execute  60 sec
  50    183001   670.93 MB/sec  cleanup  61 sec
  50    183001   664.72 MB/sec  cleanup  61 sec

Throughput 670.942 MB/sec 50 procs
RAID is great!
chunkey is offline   Reply With Quote