Poor read speeds on RAID-0 array...

[Sumanji]

Hey dudes,

I was just running CrystalDiskMark for fun on my RAID-0 array (2 x 74GB Raptors on Intel ICH9 with 64k stripe). The read speeds however seemed very poor - especially 512k chunks. I've googled similar setups, and 512k reads are in the 60MB/s range! I tried enabling the volume write-back cache in Intel Matrix manager, but that made things worse!

Stock settings:

VWBC enabled:

Any ideas what I can do to boost read speeds? Surely my read speeds should be quicker than the write speeds

Cheers,

Su

 

[Corasik]

Do you have the NTFS partition aligned with the 64k stripe size, its a common issue before windows 7 which affects SSD's a lot, and fast raid0's a little. If the array was built and partitioned on windows 7 it should be ok though.

 

[Corasik]

Score seem a bit low, what OS did you initially build the array under, Windows XP and Vista often make alignment errors which really hurt NTFS performance

For reference, My Raid0 array is a pair of 7200rpm Seagate 7200.10 disks, and this is my Crystalmark report.

--------------------------------------------------
CrystalDiskMark 2.2 (C) 2007-2008 hiyohiyo
Crystal Dew World : http://crystalmark.info/
--------------------------------------------------

Sequential Read : 147.687 MB/s
Sequential Write : 145.996 MB/s
Random Read 512KB : 51.561 MB/s
Random Write 512KB : 64.625 MB/s
Random Read 4KB : 0.830 MB/s
Random Write 4KB : 2.404 MB/s

Test Size : 100 MB
Date : 2010/01/16 14:33:08

 

[Sumanji]

Hey,

As far as I can remember I have always used Vista Ultimate x64 with this motherboard (the DVD is vanilla with no SP's slipstreamed). How can I tell whether the parition is aligned properly or not?

Cheers,

Su

 

[Corasik]

Just checked, and normally Vista will make a fair stab at partition alignment, so really its only XP users that need to worry about it.

Diskpart is a command line tool for checking all the details of your drives, and partitions.

start/run/diskpart

the usefull commands are...

list disk (show list of disks)
select disk (the name/number of your raid)

list part
select part (the number of the primary partition on your raid)

detail part

The last line of the detail should be an Offset in Bytes, of :1048576

This particular offset is a handy multiple of most common stripe sizes do its a generic "this works" offset for performance.


Really dont know why your scores are so low, as the access time on the raptors is a whole lot faster than my 7200.10 seagates, and my disk controller is the Intel ICH7R so an older one than yours.

 

[Sumanji]

Looks like 1024kb in is listed after "list part"? I don't know why the scores suck

What are your HDTach scores like Corasik? The numbers seem better in that:

Cheers,

Su