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Re: mpt Serious performance issues

On Fri, 26 Nov 2010, Stephan wrote:
I already sent this to netbsd-users but didn´t get an answer. The
Netbsd mpt driver in release 5.0.2 and 5.1 does perform extremely slow
on LSI Logic 1030 RAID controllers. Some findings:

Write speed:

# dd if=/dev/zero of=myfile bs=4096 count=10000
10000+0 records in
10000+0 records out
40960000 bytes transferred in 12.762 secs (3209528 bytes/sec)

Read speed after reboot:

# dd if=myfile of=/dev/null
80000+0 records in
80000+0 records out
40960000 bytes transferred in 6.929 secs (5911386 bytes/sec)
Obviously, there is no write cache. FreeBSDs mpt driver is performing
much faster (over 60MB/s). What could be wrong here?

I'm surprised by the read speed, but even under Windows I see terrible write performance with the 1030. Copying a large file so overloads the machine that the pointer keeps jamming for a few seconds.

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