Raid 0 questions

[Souji4]

greetings everyone,

I'm about to build a new rig and am considering putting 2 identical 200GB HDs in RAID 0 array. (I have a spare 80GB for backup) Problem is, I know very little about RAID and my mobo manual (Asus P4P800 Deluxe) is far from detailed. So I have a bunch of questions ranging from stupid to..well, still stupid. Anyways, I'll try to keep it short and simple 🙂

1. If mobo has 2 channels and I have 2 drives, do I connect both drives to one channel w/ 1 IDE cable or use both channels w/ 2 cables? Any diff??
2. Standard IDE cables will do, right?
3. Can I partition a Raid 0 array? If so, do I do this under Win XP or thru the BIOS?
4. Lastly..what's the process to configuring this rig?? Is this correct? a) Install HDs on Raid channel b) create array thru BIOS c) Create partition thru Win XP CD & format to NTFS??? d) Install Win

I'm really iffy about question 4..any help appreciated! thanks!

 

[Shooters]

1. You can do it either way, but the smart thing to do would be to put them on separate channels since only one IDE device can be accessed at a time on a channel.
2. Yes
3. Yes, you can do it during the WinXP installation just like you would with a single drive.
4. That is correct.

What are you going to be using the computer for? I ask because depending on the application, you may see little or no benefit from a RAID 0.

 

[Souji4]

thanks for the quick reply!

I originally planned on using RAID just for media encoding and using my "spare 80GB backup" for my OS and data. But now that I've found out I can partition the RAID (thnx again for reply), I might as well use the RAID for WinXP as well as media encoding. I was hoping that it would let me enjoy a quick boot time as well as efficient multimedia processing. By that I mean Photoshop w/ large files and video encodes. I plan on using an in-between block size of 32K -should I go bigger? smaller?

In what cases would I see no benefit from RAID 0?

 

[tallman45]

Raid 0 will not provide you with faster boot times. Raid 0 shines when using large files, small file read writes actually are hindered when striped.

For best performance each drive should be on it's own channel, BUT you cannot put optical drives on those Raid channels, so you need a mobo with more than 2 channels.

Remember that the data in a Raid 0 array is not safe, should one drive fail the entire array is lost. 400gb is a lot to lose. Be sure to have a backup plan

 

[Shooters]

Your boot times might be a little better, but WinXP already boots pretty darn quickly, so the improvement may be negligible. Tallman45 is right, since RAID actually tends to decrease your hard disks' access times, performance will degrade when dealing with many small files, but for large files, RAID 0 can offer a great performance improvement.

As for media encoding and stuff like that, it really depends on the situation. If you're going to be copying, transferring, capturing, etc. raw video and audio, then RAID 0 would be a good idea since these files can be huge, but from a pure encoding standpoint, RAID 0 will probably offer nothing since the speed at which you can encode multimedia files (such as when converting a WAV to MP3 or when compressing a video file with DivX) is largely dependent on your CPU, not your hard drive. With Photoshop, I would have to say that more RAM would be a better idea than a fast hard disk drive system.

I've never actually run a RAID setup before, so I can't really comment on the stripe size other than to say that it really depends on what the computer will be used for. There really is no magical stripe size that will perform well in all situations. I suggest you give this article a read as it talks a little bit about stripe size and how it affects performance.

And as Tallman45 said, the chances of you losing all your data increases with every drive you add to a RAID 0 setup, so be sure to backup any important data, which is something that everyone should be doing anyway even with only one drive.

 

[VTrider]

Originally posted by: tallman45

...Raid 0 will not provide you with faster boot times.

...Remember that the data in a Raid 0 array is not safe, should one drive fail the entire array is lost.

I've been using a RAID 0 (2x120 WD SE 8mb) for the first time now, about 4+ months. I've noticed a faster OS boot (Win XP Pro) time, but it very well could be the same time if I were using an individual one of those drives alone. Data on a RAID 0 array not being safe is a relative issue, flying on a plane 2x as much as usual will increase your chances of dying in a plane crash 2x as much also if you want to look at things that way?

-VTrider

 

[chocoruacal]

Originally posted by: tallman45
Raid 0 will not provide you with faster boot times. Raid 0 shines when using large files, small file read writes actually are hindered when striped.

For best performance each drive should be on it's own channel, BUT you cannot put optical drives on those Raid channels, so you need a mobo with more than 2 channels.

Remember that the data in a Raid 0 array is not safe, should one drive fail the entire array is lost. 400gb is a lot to lose. Be sure to have a backup plan

Thats the best advice you'll get. Pay attention to it since you're a self proclaimed RAID noob. Don't be sucked in by all the 'Net pimpsters...most likely RAID0 will do absolutely nothing for you. To add to what Tallman said...your programs and OS will probably run slower on a striped array, and yeah, huge file transfers are where it will shine. Unless you have a way to backup 400 gigs of data, or the data on the drives will be unimportant, I'd leave them alone 🙂

 

[Sheriff]

1) Each on seperate Master Channels
2) Yes Standard ATA 100 IDE Cables
3)Yes-make sure you install the RAID Drives before Windows XP when it asks (between #4 c&d)

Larger Stripe size is better for larger files such as Videos

 

[Shooters]

Originally posted by: Sheriff
Larger Stripe size is better for larger files such as Videos

But on the flip side, any file smaller than than the stripe size will not get striped across the drives, effectively destroying the whole purpose of a RAID 0.

 

[Souji4]

Raid 0 will not provide you with faster boot times. Raid 0 shines when using large files, small file read writes actually are hindered when striped.

interesting. When I ran a search for "raid 0" on this forum, I've read contrasting info. Some say boot times were much faster. another said that b/c it had to detect the RAID, it would slow. But this info comes as a surprise since many of the threads pertain to booting from RAID 0.

For best performance each drive should be on it's own channel, BUT you cannot put optical drives on those Raid channels, so you need a mobo with more than 2 channels.

That's OK, the Asus P4P800 Deluxe has 2 RAID channels and ofcourse standard IDE channels.

Remember that the data in a Raid 0 array is not safe, should one drive fail the entire array is lost. 400gb is a lot to lose. Be sure to have a backup plan

Well, the OS and installed programs will be Norton Ghosted onto CD-R, and important data will be manually mirrored between the RAID array and my extra 80GB Maxtor. And while it would be an annoyance to lose them, the large media files sitting on the massive RAID partition are disposable.



And finally a question that I forgot to ask: what is it that I'm reading about having to install RAID drivers during the installation of WinXP (by pressing the F6 button at a certain time..)?? does this apply to me if the RAID controller is integrated into the mobo? or is this only for running a software raid?

3)Yes-make sure you install the RAID Drives before Windows XP when it asks (between #4 c&d)

I guess this pertains to my question above. Why is it that Windows requires drivers for RAID? I thought it would be handled on the hardware level by the mobo? Does this mean that if I Norton Ghost my OS and transfer it to a non-RAID HD, it will have unnecessary RAID drivers in it? Or if I do it vice versa (Ghost of non-Raid to Raid HD) it will not load b/c it's missing drivers?

But on the flip side, any file smaller than than the stripe size will not get striped across the drives, effectively destroying the whole purpose of a RAID 0.

It seems to me that larger stripes can only help, where as small stripes may help and hurt. For small files a large stripe won't write/read any slower than a single IDE. But large files will benefit from the large stripe. On the other hand, while small files benefit from small stripe, large files don't just receive no benefit, it actually hinders performance.. Thus, would it be safe to conclude that I should go for a large stripe size, within reason ofcourse (around 64K)?

I'm really surprised that I've gotten so many mixed replies (all of which I appreciate greatly 🙂 ) I've always thought that RAID 0 could only help. I guess it's not so clear cut, huh? Anandtech did state: "We were more than a bit worried that even the "fast" RAID 0 did not do anything to performance but hinder it. As our real-world Content Creation Winstone 2001 scores show, RAID 0 does indeed increase performance, and by a noticeable amount." I'm just not sure what Content Creation Winstone tests for and whether or not it'll apply to me

To be honest, another reason I wanted to go RAID is b/c I'm fed up w/ the millions of drive letters on the computer I'm using now and I figure I might as well go RAID 0 than create an essentially inferior JBOD array.. (for the record this computer has drives C,D,E,F,G not including 2 optical drives..)

 

[Souji4]

up you go

any help on the driver questions? 🙂

 

[Sheriff]

Windowx XP does have drivers, just some of the chipsets have newer ones and better compatibility and the RAID0 is more of a Software RAID then Hardware issue.

When you GHOST it over from the RAID0 it won't have unnecessary RAID drivers as the MoBo you Ghost from will have to have a RAID chipset in the OS anyways or you couldn't Ghost from it to begin with.

The larger size in stripe would have much amount of wasted space not used if all you have is small files.