Which is faster Raid setup

BadCharlie

Just this week i set up a raid 2x200 gigs. I set the raid to 1 mirrored. But im now wonder is raid 0 faster ? When i say faster as in faster to load games, apps and booting up ?

Thanks

GHOST MGG

raid 0 is faster for loading stuff like apps and games

Capt'n Midnight

If 3% of hard driver die each year then you've a 97% chance of it not failing.
At that rate with two drives you are down to about 94% chance of loosing everything if either drive fails, at which point your speed will be Zero +/-

If you go for raid 0, unless you have a good backup then on average most of the time saved by the speed will be lost on the rebuilt.

Khannie

Agree with the captain there. If you have a decent backup solution then go with Raid0.

Your chances of catastrophic data failure are much higher with it though.

Jammer

what do u people have saved on ur computers?

I'm in a position where if my hdd's fail in raid0...its not big deal. CD/DVDRWs were invented for a reason, and not the illegal kind

Gilgamesh

Raid 0 (striping) splits the information copied to the drives evenly, meaning, block a will go to the first drive and block B to the second.
With Raid 1 (mirroring) the same Data will be copied to both drives.

Raid 1 also means you effectively have 200 GB with the two drives you have.
Raid 0 will give you the 400GB.

if you backup the impotant data and you are not rigging a Server with it, I would recommend the Raid0 solution

Khannie

I thought raid 0 would only give you 200 gigs at twice the speed (in theory), no?

Jammer: I don't use raid, though I will in my next machine. I will use raid0 and will be making regular backups of important stuff.

Jammer

raid 0 gives full allocation of space. it just spreads the data between the two disks. so when the machine is calling the data both HDD's are spinning, thoeretically (sp?) giving you 14,400RPM HDD speed..

Gilgamesh

Jammer wrote:

raid 0 gives full allocation of space. it just spreads the data between the two disks. so when the machine is calling the data both HDD's are spinning, thoeretically (sp?) giving you 14,400RPM HDD speed..

coudn't have explained it any better
Also, it uses the Cache from both of the drives, increasing general memory access

Diarmuid

There's a good saying about hard drives. "It's not a case of if the drive fails but when the drive fails"

With raid0 you are halving the time you have to wait for your first hard drive failure. Restoring 200Gb from DVD's is one very painful task. I can wait the extra second(s) it takes for my apps to load. I guess some can't.

BadCharlie

Thanks guys for all the replays. I think over the weekend im going to be installing windows again as i want the speed. Just as well i have not much installed since i set it up during the week.

Raid 0 here i come!!

Khannie

Jammer wrote:

raid 0 gives full allocation of space. it just spreads the data between the two disks. so when the machine is calling the data both HDD's are spinning, thoeretically (sp?) giving you 14,400RPM HDD speed..

Gotcha. How about sacrificing half your disc space for mirroring then, so the data is on both disc a and b, read from both (so super fast), but mirrored in case of a screw up. Is that possible?

Jammer

Diarmuid wrote:

There's a good saying about hard drives. "It's not a case of if the drive fails but when the drive fails"

With raid0 you are halving the time you have to wait for your first hard drive failure. Restoring 200Gb from DVD's is one very painful task. I can wait the extra second(s) it takes for my apps to load. I guess some can't.

i have a 2.3GB HDD thats 9 years and six months old. Its still going strong! Its in a (very) old Pentium 1 MMX. I've been using several hard drives in the last 5 or 6 six years and never had one fail. Am i just lucky or do people eaggerate alot?

NASA wouldn't even have 200GB of information thats that important! :rolleyes:

Jammer

Khannie wrote:

Gotcha. How about sacrificing half your disc space for mirroring then, so the data is on both disc a and b, read from both (so super fast), but mirrored in case of a screw up. Is that possible?

doesnt work like that. google RAID 0+1 , its kind of what your saying...need 4 disks (exactly same model) and obviously 4 S-ATA ports. Basically its raid 0, but everything is backed up aswel...

epgriffin

I've noticed here on boards that people regularly put down raid 0 due to an increased chance of drive failure. Fair enough, you have 2 drives and if 1 of them fails you're in trouble.
But, if you consider that only 44% of data loss is due to hard drive failure, you personally are more likely to lose everything through pure stupidity so regular backups are essential regardless of hard drive setup.
Secondly, a large majority of hard drive failures are due to failed electronics, read/write heads, head assemblies. In a raid 0 setup since the workload is shared amongst the drives they (individually) put the above components under less stress than they would if they were taking the entire load on their own or in a raid 1 setup. So the failure rates actually cancel one another out....

po0k

Raid5 tbh.

Capt'n Midnight

epgriffin wrote:

IIn a raid 0 setup since the workload is shared amongst the drives they (individually) put the above components under less stress than they would if they were taking the entire load on their own or in a raid 1 setup. So the failure rates actually cancel one another out....

LOL
RAID 1 (mirror) is faster than a single disk on Read , because you use which ever drive gets there first, it's slower on Writes because you have to write the same data to both disks.

With RAID 0 if the data is stripped (64KB block anyone ?) across both drives then both get used for almost every drive operation - not much less stress.

If you have two drives with different letters you can control what is going on.
eg: Put the OS on a (say) 20 GB partition on Drive 1 - then before you install any software put a swap file there of (say) 10GB fixed size. This will now stay at the start of the drive so very low seek times. Install your apps and data to the second drive. This way you split the disk thrashing a bit - maybe , there are lots of pros and cons whichever way you go.

RAID 5 is nice , but expensive and mirroring means you can recover the data if you don't happen to have that specific RAID card. Software RAID 5 is not a great idea.

leeroybrown

Khannie wrote:

Gotcha. How about sacrificing half your disc space for mirroring then, so the data is on both disc a and b, read from both (so super fast), but mirrored in case of a screw up. Is that possible?

A 'good' hardware RAID1 implementation will offer that. The controller should be able to stripe the reads off the disks as the RAID1 element only comes into play when a read error occurs. The writes will obviously still happen at the same (or slightly slower) speed.

leeroybrown

Capt'n Midnight wrote:

With RAID 0 if the data is stripped (64KB block anyone ?) across both drives then both get used for almost every drive operation - not much less stress.

Agreed, the drive spindles still spin at the same speed and the heads will end up in sync following each other.

Mercury_Tilt

This post has been deleted.

Capt'n Midnight

epgriffin wrote:

So the failure rates actually cancel one another out....

It's much easier to boot from the dark side of a broken mirror ( add another line to the Boot.ini or swap the cables ) into a fully working system than retrieve any size of data from a failed RAID 0

vibe666

i have 4 wd400's (40gb ide drives) and plan on getting some ide to sata converters and using them as a raid 0+1 set. i have to say my mobo is great. 1x4 port sata raid controller and 1x2 port sata with the usual ide controller too. with 6x 3.5" and 4x 5.25" bays in my case, i'm set. just need to find some nice low profile converters (seen some on ebay fairly cheap) an I'm all set.

am i really going to see much performance increase with 0+1 in real world terms?

i plan on having the second 2 port sata raid set as 0 for video editing and capture (have 2 other identical drives for that), but i was wondering where to put the swap file, either keep it on the boot partition or on the other raid 0 set. what do you think would be better, if anything? or am i just over thinking it all?

po0k

Mercury_Tilt wrote:

This post has been deleted.

Pussy

po0k

vibe666 wrote:

i have 4 wd400's (40gb ide drives) and plan on getting some ide to sata converters and using them as a raid 0+1 set. i have to say my mobo is great. 1x4 port sata raid controller and 1x2 port sata with the usual ide controller too. with 6x 3.5" and 4x 5.25" bays in my case, i'm set. just need to find some nice low profile converters (seen some on ebay fairly cheap) an I'm all set.

Make sure you've got a good quality power supply with a rating of 400W+ and good rail specs.
Each hdd will draw about 10-12W roughly (including the safety margin).

vibe666 wrote:

am i really going to see much performance increase with 0+1 in real world terms?

If all the drives are 7200rpm, you should see a good improvement in speed, providing your stripe size is optimal.
Theoretically, you could see 2x write performance and 4x read over a single WD400. Depends on your controller too, and whether it's just a 'container' or a proper hardware raid1/0 contoller.

vibe666 wrote:

i plan on having the second 2 port sata raid set as 0 for video editing and capture (have 2 other identical drives for that), but i was wondering where to put the swap file, either keep it on the boot partition or on the other raid 0 set. what do you think would be better, if anything? or am i just over thinking it all?

Put the swap file on the raid0 set.
If it gets lost, it gets lost. Wouldn't do any damage.
When you're capturing stuff you shouldn't be using the pagefile, so it should't impact.

astrofool

Set up 4 15k ultra320 SCSI's in raid 5 in the lab the other day, was pretty fast

They overheat very quickly however, 3rd degree burn type heat without a big big fan.

zAbbo

Setup a win2k server on raid 1+0 on a compaq ml370 today, will be testing it over the weekend

leeroybrown

People should also bear in mind that RAID 1+0 and RAID 0+1 are actually two different things with RAID 1+0 being a preferable solution.

RAID 1+0 is a stripe built from multiple mirrored sets of two drives. RAID 0+1 is a mirror of two stripes. In RAID 1+0 arrays with more than 4 drives a double drive failure has a significantly lower chance of wiping out the data as both failed drives must be in the same mirrored pair. The loss of a drive causes less speed degradation in RAID 1+0 arrays as only a portion of the stripe is affected and the rebuild overhead is far less as only one drive will need to be re-imaged.

Well worth bearing in mind if you want high availability.

BadCharlie

Well computer is now set up as raid 0. Did some benchmarking on the setup and it scores higher then my 36gig WD raptor drive. That raptor was not cheap but nor was my 2*200gig sata drives. But at least i get 380gigs of storage in my current set up.

vibe666

SyxPak wrote:

Make sure you've got a good quality power supply with a rating of 400W+ and good rail specs.
Each hdd will draw about 10-12W roughly (including the safety margin).

i have the sharkoon 350w silentstorm PSU.

SyxPak wrote:

If all the drives are 7200rpm, you should see a good improvement in speed, providing your stripe size is optimal.

yep, all 7200rpm drives. can i set stripe size in the raid bios or something like that? what's the best size? is there a faq anywhere for something lke that?

SyxPak wrote:

Depends on your controller too, and whether it's just a 'container' or a proper hardware raid1/0 contoller.

the mobo is an abit IC7-MAX3. actually, most of the parts were bought off boardsters, so the parts probably seem familiar to some of them.

with ragard to the swap file, i think i've confused myself with windows pagefile (a common mistake) is it still better off on the RAID0 set than the 0+1?

Diarmuid

epgriffin wrote:

So the failure rates actually cancel one another out....

Sorry but that's just plain wrong. The failure rate for your setup is DOUBLE what a single drive would be.

There are tons of review/commentaries on this on the web including storagereview.com

http://faq.storagereview.com/SingleDriveVsRaid0

Some snippets (they have the benchmarks on the web site) :

What about performance? This, we suspect, is the primary reason why so many users doggedly pursue the RAID 0 "holy grail." This inevitably leads to dissapointment by those that notice little or no performance gain.
...
There are certain uncommon situations where RAID 0 can significantly improve system performance. For example, editing of large audio or video files is sometimes limited by the maximum sequential transfer rate of the hard drives, but it is far more common for the processor to be limiting factor. Generally, if you frequently make simple edits to large media files, RAID 0 can potentially improve your productivity.
...
So what's a "real world" speed increase of typical Windows and Linux applications? It is difficult to put a solid number on this figure, because of the diversity of software out there, but it is reasonable to assume a 0% - 15% overall disk performance increase moving from a single disk drive to two in RAID 0, with rapidly diminishing returns as you add more drives.
...
Unsurprisingly, the dual-drive RAID 0 solution delivers double the sequential transfer rate of a single unit. The SR Office, High-End, and Gaming DriveMarks, however, all climb by less than 10%.
...
The point? Dont assume RAID 0 offers increased performance for all or even most applications... and dont assume that transfer rates reflect application-level performance.



the bottom line .. you hard disk related benchmarks will improve. your "real world" performance will BARELY improve.

I think the obvious bottom line is "don't bother" , but hey, it's your computer and your data

Gilgamesh

think this thread has been chewed out enough by now.
Diarmuid has the best answer to it.

it is going off topic now, and would recommend to maybe start a new thread if you want to start one of those slugfests about what is better.

alantc

Re people asking who has 200gb of important data.

Probably nobody. I certinaly dont but there's no way i want to have to go through all the hassle of finding all my bookmarks/mp3s/cd backups again and also the little text flies that I've left as notes for myself that I'll never get back, reinstalling windows and setting it up nicely again like it is just because my hard drive has broken.

For me it's all down to convenience. Well worth spending an extra e100 for the peace of mind. I never bother with backups. They're a great idea and all but I never bother (I presume the majority of PC users dont).

If you've ever had a hard drisk fail you'll remember the pain in the ass it was afterwards and that one persons email address that you needed and didn't have.