Improving Win 2008 R2 RAID-5 Write Performance

[decryption]

I've set up a Windows 2008 R2 file server, using Windows software RAID-5 and having a bit of an issue with write speeds. These are the specs of the file server:

• Athlon II X2 240 CPU
• Gigabyte GA-MA790UX-UD4P mainboard
• 2GB DDR2-800 RAM
• Seagate ST9250315AS (250GB 2.5" 5400RPM HDD) boot drive
• 2x Intel SASUC8I (LSI 1068E chipset) HBA non-RAID disk controllers
• 20x 1.5TB Western Digital WD15EAS SATA HDDs
• Windows 2008 R2

Logical volumes are laid out like so:

• (tv) 10x HDDs - RAID-5
• (movies) 7x HDDs - RAID-5
• (music) 3x HDDs - RAID-5

I'm a bit disappointed with the performance, particularly writing - I seem to only get about 30-40MB/s for sequential writes. Anyone have any tips on how it can be improved?

 

[Blue Fox]

Unfortunately software RAID has always been lacking in the performance department. It is something you might have to live with. At least I can't really think of anything that you can do.

 

[extide]

How is your cpu usage when writing? Is it even getting close to pegging a core? If so, you can try overclocking it a bit, but be careful and make sure it's 100% prime safe or you WILL corrupt your data


Also, try making your arrays spread across the cards, like for that big 10 drive one have 5 drives on each card, etc.

 

[SpaceHonkey]

Are your partitions aligned? If not, you will get terrible performance - as you're seeing.

 

[danman]

Has your array initialized?

 

[extide]

Are your partitions aligned? If not, you will get terrible performance - as you're seeing.

Aligned to what? Mechanical drives don't care about alignment...

 

[nitrobass24]

Aligned to what? Mechanical drives don't care about alignment...

ORLY?
http://msdn.microsoft.com/en-us/library/dd758814.aspx

 

[keenan]

Unfortunately Windows software RAID has always been lacking in the performance department.

T,FTFY. The solution of course is to switch to a *nix .

Aligned to what? Mechanical drives don't care about alignment...

No, but if the filesystem blocks don't align with the RAID blocks you will incur a pretty serious write penalty. It shouldn't be as serious as the OP is experiencing though (assuming he's quoting numbers for streaming writes and not random blocks), so it's probably just the widely-reported-as-useless Windows softraid implementation.

 

[extide]

ORLY?
http://msdn.microsoft.com/en-us/library/dd758814.aspx

Hrmm I wasnt thinking of aligning to the raid stripes.