RAID0 no faster than SATA

[EnglishLion]

I've just set up a RAID0 array and it's no faster than my previous SATA1 hdd. I'm using two SATA segate 80Gb drives to create a 160Gb array. ASrock DualSata2 mobo.

I haven't seen any great improvement so I installed and ran PCmark05 and it scored ~ the same in both 'xp startup' and 'general hdd usage' tests.

I wasn't sure what to set as stripe size, so I went for the default 16K.

Am I missing a trick here?

[wazzledoozle]

What transfer speeds are you getting? Burst/sustained...

[Aevum]

take in to account that the secret to speed in raid0 is that you have x as much reading heads on x as many plates, the increse in speed is dependent on distribution of data between the drives, x being the number of drives,

you get x the speed if the data you are reading from the array is distributed equaly between all the drives in the array, but if its distributed asymetricly, the speed increse will be less noticable,

[KennyT772]

well are you by chance using drives with dif revisions?

[yogurt_21]

160gb array out of 2 80's? thats spanning my friend. not striping. striping makes both drives become one at double the speed but limits it to 80GB storage for both drives. spanning makes both drives run as one drive with double the capacitiy but doesn't create any speed boost. mirroring is the other which makes both drives aquire the same infor as a backup.

[newtekie1]

160gb array out of 2 80's? thats spanning my friend. not striping. striping makes both drives become one at double the speed but limits it to 80GB storage for both drives. spanning makes both drives run as one drive with double the capacitiy but doesn't create any speed boost. mirroring is the other which makes both drives aquire the same infor as a backup.


No, RAID 0 is striping, and striping is when you take 2 drives and half the data gets written to one and half to the other. So 2 80GB drives striped together will give 160GB of total space, and theoretically double the read/write performance.

http://www.acnc.com/04_01_00.html

Time for someone to bone up on their RAID knowledge.

[KennyT772]

raid 0 = striping
raid 1 = mirroring
jbod = spanning

[wtf8269]

This happened to me with my old Gigabyte GA-K8ns Ultra 939. It was due to a piss poor SATA controller. I only got 118mbps there and I get around 225mbps with my DFI.

[EnglishLion]

What transfer speeds are you getting? Burst/sustained...

http://www.rowan-house.net/forums/raidspeed.jpg

They are slightly diff drives (revision) but they are both seagate 80gb SATA drives. No-one's mentioned the stripe size yet. Is 16k alright? What other stripe sizes do people use?

[Jimmy 2004]

I should be setting up RAID 0 later today if my new hard drive works. I'll let you know how I get on.

[G.T]

Time for someone to bone up on their RAID knowledge.
hehehe, preach on.

[EnglishLion]

Well I've now run Sandra 2007 and the file sys and hdd benchmarks come up nice and quick! Just don't see it in PCMark05 or in real windows situations.

I'll have to patch up my bf2 (Just re-installed it) and see if map loading is quicker!!

[Jimmy 2004]

Well I've now run Sandra 2007 and the file sys and hdd benchmarks come up nice and quick! Just don't see it in PCMark05 or in real windows situations.

I'll have to patch up my bf2 (Just re-installed it) and see if map loading is quicker!!

RAID is for loading times generally, not actually gaming or processing performance (other than the pagefile being a little quicker).

[EnglishLion]

RAID is for loading times generally, not actually gaming or processing performance (other than the pagefile being a little quicker).

Unfortunately it doesn't load XP any quicker though. And map loading in games is surely a type of loading?

[KennyT772]

well it is. and the reason you arnt getting faster times is due to the different revisions. when a raid controller sences different drives - be it actually different of just revision - raid 1 will still function correctly as it isnt speed dependant but raid 0 will run at the speed of the slower drive, in all circumstances.

[yogurt_21]

No, RAID 0 is striping, and striping is when you take 2 drives and half the data gets written to one and half to the other. So 2 80GB drives striped together will give 160GB of total space, and theoretically double the read/write performance.

http://www.acnc.com/04_01_00.html

Time for someone to bone up on their RAID knowledge.

i wasn't arguing that raid 0 isn't striping lol,
I was pointing out that no raid 0 array of two 80gb hard drives will be 160gb.
didn't catch that did you?

time for you to bone up I guess. or read. lol which seems to be a major epidemic on these forums, no one seems to do it.:shadedshu
if he were running in a raid 0 striping array the two 80gb discs would run as a single 80gb disc. and btw the rerason I pointed it out is because when running a spanning array on my gigabyte board it interprets it as raid 0, it's wrong, but it doesn't change the fact that it reports it that way. which is probabaly what happened to englishlion.

he thought he was running in a striping array and actually is running spanning which would explain the double capacity and regular speed. seriously read the post next time dude.

[KennyT772]

um yogert take your own advice. if you are only writing half the file to each drive how does each file take twice the amout of data vs a single drive??? if you can explain that then i guess i am wrong.

capacity of raid 0 is the sum of the discs (80+80=160gb)
capacity of raid 1 is the sum of the discs divided by the amount of discs (80+80=160/2=80)
capacity of raid 0+1 is the sum of the discs divided by two (80+80+80+80=320/2=160)

you are saying raid 0 is raid 1. i personally have a raid 0 array of twin 80gb wd ata133 dives running on my home file server. i would really like to see how i have 160gb worth of storage in my raid 0 but you claim i only have 80gb.

[markkleb]

The default stripe should be 64K (im pretty sure)

I have uses Raptors, single and Raid0
Segates, single and Raid0
And my Hitachi Sata2 in Raid0 (4 of em)

I notice a difference in all the raids, but the biggest difference I noticed was using a 16mb buffer Maxtor. It seemed faster than the raptors(36 Gig).

This is a ATTO of my 4 Hitachi Sata2's

[Jimmy 2004]

i wasn't arguing that raid 0 isn't striping lol,
I was pointing out that no raid 0 array of two 80gb hard drives will be 160gb.
didn't catch that did you?

time for you to bone up I guess. or read. lol which seems to be a major epidemic on these forums, no one seems to do it.:shadedshu
if he were running in a raid 0 striping array the two 80gb discs would run as a single 80gb disc. and btw the rerason I pointed it out is because when running a spanning array on my gigabyte board it interprets it as raid 0, it's wrong, but it doesn't change the fact that it reports it that way. which is probabaly what happened to englishlion.

he thought he was running in a striping array and actually is running spanning which would explain the double capacity and regular speed. seriously read the post next time dude.

RAID 0 uses the technique of striping in order the share data accross drives without losing any storage capacity.
RAID 1 uses mirroring to have the same data on both hard drives while losing 50% of your potential space.
RAID 0+1 requires at least 4 hard drives and uses both techniques at once.

Look here (http://www.pcguide.com/ref/hdd/perf/raid/levels/singleLevel0-c.html).

[EnglishLion]

Well RAID 0 definately allows full use of all the available drive space. 2 x 80 = 160gb. I know that for certain.

However, I think my mistake was using too small a stripe size. My controller is the onboard Ali controller too and I think that's limiting. If I set it up again at any time it'll be a 64K stripe I think!

[bim27142]

No, RAID 0 is striping, and striping is when you take 2 drives and half the data gets written to one and half to the other. So 2 80GB drives striped together will give 160GB of total space, and theoretically double the read/write performance.

http://www.acnc.com/04_01_00.html

Time for someone to bone up on their RAID knowledge.

agree!!!

[vrdublu]

Actually for stripping its better to have a larger stripe size, apparently the larger the better, somewhere in the 128k to 256k if thats possible. I am currently using 128k myself.

[EnglishLion]

64k is the largest my controller offers

[tony929292]

it alway a small speed increase but it is an increase so yhat why people use raid 0

[newtekie1]

i wasn't arguing that raid 0 isn't striping lol,
I was pointing out that no raid 0 array of two 80gb hard drives will be 160gb.
didn't catch that did you?

time for you to bone up I guess. or read. lol which seems to be a major epidemic on these forums, no one seems to do it.:shadedshu
if he were running in a raid 0 striping array the two 80gb discs would run as a single 80gb disc. and btw the rerason I pointed it out is because when running a spanning array on my gigabyte board it interprets it as raid 0, it's wrong, but it doesn't change the fact that it reports it that way. which is probabaly what happened to englishlion.

he thought he was running in a striping array and actually is running spanning which would explain the double capacity and regular speed. seriously read the post next time dude.


Again, try to at least know what you are talking about before you post, please.

RAID 0 is the sum of the drives, so 80+80=160. Come on, I gave you the damn link telling you all of this, you didn't even have to use google...looks like you are the main cause of the epedemic on these boards.

Striping is what he is running. JBOD is spanning and can be mistaken for RAID 0 in some cases, but he specifically said he was running RAID 0 and striping. So seriously read the post next time, and at least have a small clue about what you are talking about before you post 'dude'.

[EnglishLion]

Well I changed to 64K, I hadn't reinstalled loads on my system, so I thought I would while it was still easy to reinstall.

It has sped things up a little, but still not by huge amounts as I was expecting

[Jimmy 2004]

Well I changed to 64K, I hadn't reinstalled loads on my system, so I thought I would while it was still easy to reinstall.

It has sped things up a little, but still not by huge amounts as I was expecting

Think yourself lucky it's working... when I finally got a second working hard drive the Nvidia drivers didn't seem to work in raid with the drives I have and wouldn't even boot into safe mode :cry: . It installed to OS fine, but just wouldn't load the final step...