Werid RAID 0 hdtune results.

[jgv115]

Have a look at this:

http://i22.photobucket.com/albums/b319/jgv115/Capture.png

My specs are in my sig. I was wondering why there is that inconsistency in the graph. And yes, this was taken when the HDD's were idle.

[nd4spdbh2]

stripe size?

i had a pair of 7200.8 80gb hds that did something very similar... i forget what stripe size fixed it.

[jgv115]

So what stripe size should I use? I doubt that has anything to do with it....

[HDCHOPPER]

I had pretty good luck with 512k & 1024k ...

If your using onboard raid the largest you can get normally is 128k IIRC hopefully 256K

[jgv115]

I think on this RAID array I am using 64k. I heard that if you don't work with big files then use something smaller.

Will I see a performance decrease if I do 128k or even 256k?

[freeagent]

Looks like your windows slice might be too small :thup:

Sounds weird I know..

[jgv115]

Alright, I've done some more testing:

128k stripe:

http://i22.photobucket.com/albums/b319/jgv115/128kstripe.png

32k stripe:

http://i22.photobucket.com/albums/b319/jgv115/32kstripe.png

Now I'm going to test my 64k and 32k again with Write back cache

[jgv115]

HOLY!!!! Check these graphs out:

System drive (64k stripe) with WBC:

http://i22.photobucket.com/albums/b319/jgv115/64kstripe-writebackcache.png

that bit I circled probably doesn't really belong in the graph. A program was probably using the drive

32k with WBC

http://i22.photobucket.com/albums/b319/jgv115/32kWBC.png

This graph IMO is a good example of what the "slower 2/3" of the HDD should look like.

Looks like write back cache fixed the inconsistencies in my HDDs. I never knew it had such an impact. The improvements are massive!! My drives are faster than a Single WD black :)

note: all the benchmarks besides the 64k one was testing using the slower part of my HDD

[HDCHOPPER]

learn something good everyday , lower stripe size for HDD and larger stripe for SDD
tried every stripe from 32k and up to 2048k on ssd & larger to 512k & 1024K worked best

And ya write back cache is a boost , best to have an UPS with that option..

your OS looks to be vista or W7 default install with both = aligned partition
XP default is unaligned partition , that is to say anyone using XP.... aligning your partition before install of XP really helps the IO's

[hitokiri_808]

Change the block size in HD Tune. If the Stripe size is larger than the test block, it alters the results.

ATTO would show the best all round performance for different test sizes.

[jgv115]

I've done that. The 64k test is done with my 64k stripe etc.

ATTO results (can someone compare theirs to mine?):

http://i22.photobucket.com/albums/b319/jgv115/Capture-1.png

[Wolverine690]

So what's better then for HDD RAIDs? I'm currently using 32K or 64k I can't recall which... but I'm working on reloading a few pc's with raids & may want to change if bigger is better...