RAID 0 performance gains?

I'm building a new computer over the summer. I'm fairly competent in computer hardware, and am thus building the computer from scratch. I have everything planned out, but I was wondering about RAID. I asked which RAID I should use earlier, but now that it's pretty clear that RAID 1 isn't really that great, I think I'll go with cloud-backup instead of disk-redundancy. However, I still face a choice: use two 1 TB drives as two 1 TB drives, or combine them into a RAID 0 striped array. Is there any performance gain at all? I know that if one drive dies, everything is gone, so is the performance gain worth it? I'm building a pretty advanced computer, with SLI video cards and a fast CPU, so I'm thinking RAID 0 would give me some good hard drive performance. From your experience, is RAID 0 viable?

NickAldwin

Posted 2009-07-23T18:16:48.517

Reputation: 1 305

Answers

Hardware-RAID-0 is always faster than a single drive because you can step the reads and writes across the two drives simultaneously. Downside is that if either drive fails, you lose data on both disks. So if your backups are good, and you are willing to take the risk of a slightly higher risk of data loss, go for it.

Software-RAID-0 can provide improvements, but in my opinion not enough to justify the increased risk of data loss. Also, you almost can almost never boot from a software-RAID-0 partition.

Wasn't there an article recently that had an obscene number of TB drives in a stripe to see how the performance compared?

David Mackintosh

Posted 2009-07-23T18:16:48.517

Reputation: 3 728

I have hardware RAID, so it sounds like RAID 0 would be a good choice. Thanks! – NickAldwin – 2009-07-23T18:57:04.830

There was a video that had 24 Samsung SSD drives raided together. Watch and want. http://www.youtube.com/watch?v=96dWOEa4Djs

– Stefan Thyberg – 2009-07-24T06:59:36.380

For bulk transfers I've found that software RAID0 (under Linux at least) performs as expected (i.e. pretty much the same as hardware RAID0). There are stripe width and read-ahead settings to tweak, which may help if you find a RAID0 arrangement performing disappointingly. Not being able to boot of software RAID0 is likely to be an issue Nick's plans though. And the inherent risk of any RAID0 arrangement, of course. – David Spillett – 2010-04-09T12:21:25.147

I think David is underplaying the risk of RAID0. If either drive fails you lose ALL DATA ON THE ARRAY. Thus you are doubling your risk of data loss. MAKE VERY FREQUENT BACKUPS! I have a RAID0 array and I treat anything on it as temporary. If you want speed and redundancy use RAID5 or RAID10. (I use RAID10 in my servers) – Josh – 2010-04-09T14:42:13.120

1@Josh: In my experience hard drives don't fail all that often, so twice the chance of failure isn't that big a deal. Your backup strategy should depend on how much work you're willing to lose more than how likely you are to lose it. – David Thornley – 2010-04-09T15:11:19.263

@David: Then maybe I experience your share of failures ;-) I experience at least two hard drive failures a year, if not many more. Then again I deal with a fair number of drives, so YMMV. – Josh – 2010-04-09T15:37:31.417

Don't do this. Instead of buying one of those TB hard drives, buy a western digital raptor or velociraptor drive. It's small, yes, but you don't need to put THAT much content on your main system drive.

What you get are latency and transfer speeds that far exceed what two large TB drives will ever be capable of. Even though the throughput from raid is pretty high, you still have to have one of your two drives find the start of a file before it can begin playback, meaning that for many smaller files, or when you're accessing lots of different files, as during startup, your raid array is not speeding things up substantially. Furthermore, it might even be degrading performance, depending on your read/write problem.

Go with a fast 10k rpm drive as your system drive for the things that need to be fast, and use a big drive for media storage. They're different tasks, use the appropriate hardware for each.

Paul McMillan

Posted 2009-07-23T18:16:48.517

Reputation: 826

Unfortunately, some of the programs I regularly use both a) put lots (think GBs) of data in the program files folder b) act funny if they aren't installed to C: meaning that I have to use a large drive as my system drive. Believe me, I prefer the other arrangement and had it on two of my other systems, but these programs tend to be annoying.

What size would you recommend for a OS-only drive, if I decided to go that way? – NickAldwin – 2009-07-23T20:43:33.997

And is the 10k rpm a huge improvement over 7200? or just marginal? I'm not sure I'm ready to spend $50 more for 800GB less. – NickAldwin – 2009-07-23T20:57:01.203

Look at the file seek times. You're looking at half or less from the huge storage drives. For tasks like booting your system, running games, anything that involves loading multiple files, the high performance single drives make a huge difference.

Obviously, for the programs that put lots of data on the drive, you use a media drive. Are you absolutely certain that the programs you use MUST be on the C drive? Also, windows xp and above include support for mounting one drive within a folder on another, so if you don't HAVE to be in the ROOT of the drive, it can look like a big drive. – Paul McMillan – 2009-07-23T21:12:27.393

I've run my system drive on the first generation 75GB raptor for a long time now. 75GB is enough for me, but your needs may vary. 250 is certainly plenty. – Paul McMillan – 2009-07-23T21:13:56.530

This doesn't really address the original question. What if I already have 2 WD VelociRaptor drives? The question is whether it's better to use them in RAID-0 or as a single drive. – EMP – 2009-07-24T03:50:43.790

His question is really "what should I do?". My answer addressed that. Bottom line, raid 0 performance is still probably better, but buying a single fast system drive is a reasonable thing to do in his case. – Paul McMillan – 2009-07-24T21:24:45.457

I'd buy an SSD and put my OS and programs on that, and use the disks for data storage.

pgs

Posted 2009-07-23T18:16:48.517

Reputation: 3 153

Raid 0 with two drives is not going to show much improvement in the way of performance. Sure there will be some, your are splitting your writes between two spindles, but not enough for it to really make a difference.

Where raid 0 really shines is when you are string many drives together, say 15. Now when you split your writes across that many drives you will surely see an improvement in your disk io and latency.

If your machine supports a hardware raid and you are looking for some performance/redundancy improvement, why not go to three drives (or four) and setup a raid 5 array. Sure there is a slight performance hit during writes, but I am willing to bet your computer usage will be mostly reads anyhow.

I just finished building a new workstation (gaming + development) for myself just two weeks ago, I decided to go with an 80GB SSD on the boot drive and three 500GB HDD's, in RAID 5 configuration, for data. I swear to you, once you go SSD, you will never go back.

Brettski

Posted 2009-07-23T18:16:48.517

Reputation: 627

Really depends on why you think you need the extra performance. Some current hard drives have some very impressive read speeds on their own. This would give you a second 1TB drive to play with.
Having had RAID-0 in my machine I didn't notice any great differences.

You could benchmark a single drive with HDTach and then do the same once you have the RAID array setup.

Henryk

Posted 2009-07-23T18:16:48.517

Reputation:

Raid 0 is excellent for non-mission critical situations. I have 2 systems that I use at home, one is for gaming, the other I do all of my browsing/email/mundane tasks. On my gaming system I use a raid 0. I gain the performance benefits such as faster texture loads, and if I have a failure, reinstalling games is no big deal. I would NEVER put raid 0 on something that I couldn't afford to lose.

DHayes

Posted 2009-07-23T18:16:48.517

Reputation: 2 103

Not even if it was backed up? – NickAldwin – 2009-07-23T20:13:08.923

It all depends on your tolerance for data loss. I have some directories backed up to NAS which I am okay with losing the local copy. In case of data loss, I'm fine with just copying things back over. YMMV. – Jauder Ho – 2009-07-23T21:30:17.583

If it is something that I feel is worth backing up, then I probably don't want to lose it in the first place. I would likely opt for a different RAID method. With RAID0, every disk you add multiplies your chance of a data failure. It's good for cheap performance, but I wouldn't use it for anything I had a slight worry about. – DHayes – 2009-07-24T13:17:22.283

With a good backup strategy, a drive failure is a matter of time, replacement cost, and inconvenience. I wouldn't want to lose stuff, so I back up to an external drive. If the internal drive fails, I haven't lost any creative work. – David Thornley – 2010-04-09T15:14:11.470

I have two 500GB Seagate v11 drives that I tried using in RAID 0 and it gave my bootup process fits... I am using one of those drives right now and since it has 32MB cache (over the 8MB I had been using..) I don't see the need in going with RAID 0. Also since I am using Windows 7, I am going to use the other 500 GB drive for the built in Windows backup feature, which I think is preferable to RAID 1 even.

My advice would be if you need speed, go with a smaller SSD (32 or 64GB) for your boot drive and use a traditional hard drive for your non-OS programs and files...

Good luck : )

John Molokach

Posted 2009-07-23T18:16:48.517

Reputation: 1

You need to carefully consider the overall system rather than just focusing on one piece at a time.

Unless you are already going all out on your other components, you'll probably get a much better performance gain by putting your money in places other than RAID 0. Memory (Size, not so much speed), CPU & GPU will all likely be much better bang for your buck.

TM.

Posted 2009-07-23T18:16:48.517

Reputation: 1 270

Yep, I've already considered all that and am getting pretty good performers in those areas. – NickAldwin – 2009-07-27T14:01:28.720

I have experienced raid0 for 2 years (2x1 TB), and i have now switched to SSD (OCZ vertex2 120 GB for system + 2x1 TB non-raid). When you run benchmarks (HD tune or CrystalDiskMark) you see that raid0 really improves performance on big file transfer (which pratically never occurs), and not much on many little files transfer. So raid0 is good for one thing : transfering hd movies and nothing else. SSD has good transfer rate AND access time, so it's good for everything (booting, launching programs, transferring big and little files...).

From a user point of wiew, raid0 compared to standard HDD usage is not really perceptible, whereas SSD really is. I also play sometimes, and i can say that games load way faster with SSD than with raid0. So when you have experienced SSD, there is no going back.

Whith that said, there is another alternative which are hybrid HDD, like this seagate momentus. I have never tested those, but judging by reviews, it seems quite promising.

Benjamin Crouzier

Posted 2009-07-23T18:16:48.517

Reputation: 4 288