To RAID or not to RAID

[jwhicks727]

I'm designing my new system, and I'm torn between two hard drive options. Option A is to get the new 150 gig Raptor (which also has a 16MB cache that previous versions did not have) as my primary drive (I'll be using a Caviar 250 gig drive for storage). Option B would be to use two of the old 74 gig Raptors (with 8MB caches) in RAID 0 for added speed.

There thing I don't understand in making this decision is just how much a striping RAID setup improves speed. Is it worth the sacrifice of the larger cache on the new Raptor to get the RAID allowed by the two old ones? How exactly and to what degree do RAID and cache size affect performance? Finally, what would you do?

I use my computer for a variety of purposes, but for the purposes of this query, assume I will be running the latest games with programs like Azureus running in the background. That will be the most demanding thing I put the computer through. Thanks.

 

[nippyjun]

My understanding is that striping raid doesn't do much for performance if any and increases your chances for failure.

 

[bamacre]

Do not go RAID 0 for your gaming machine. The performance gain is almost zero. Plus, you have double the chance of losing your data.

 

[Jiggz]

If you want speed for games, do not go for RAID 0. Although you will see an increase in loading there's not a whole lot in performance while at the same time doubling your chance of hdd failer. If you want to raid 0 for disk intensive application like photoshop or graphics then go for it. But you need to make sure you always have a back up of the raid.

 

[oog]

no raid

 

[Apocalypse X]

Its real obvious to me that none of you are hardcore gamers.
Go raid0 you will see a tremendous increase.
Speaking from experience....not from reading some review by a person who plays Hearts....or 3d checkers.

 

[John]

Welcome to AnandTech. A similar thread was only a few posts down.

http://forums.anandtech.com/messageview...atid=27&threadid=1791095&enterthread=y

 

[letstalkcisco]

I ran RAID0 for a while and didn't notice any improvement in gaming experience (HL2, AA, FEAR) or really in anything except for copying things to my HD. Loading times were only slightly shorter.

The new 16mb raptor would be sweet if you have the 300 to drop on it. I'm still waiting for the price on the 74gig one to come down some more. I'm currently able to run all my games at the highest settings with my 3700+ and 7800gt -- the hard drive doesn't really play into the equation, and a 10k rpm hard drive would only allow me to lessen loading times.

The only reason I'd go raid again is strictly for the fun(?) of it.

 

[alimoalem]

anand's done an article on the new raptor and i believe it includes benchmarks for the 74 gig along with it. maybe that'll help

 

[bamacre]

Originally posted by: Apocalypse
Its real obvious to me that none of you are hardcore gamers.
Go raid0 you will see a tremendous increase.
Speaking from experience....not from reading some review by a person who plays Hearts....or 3d checkers.

Bull. I've ran dual 74GB raptors, and I still say a BIG :thumbsdown: to raid 0.

 

[Madwand1]

Going to dual Raid 0 will improve your perfomance over a single larger drive, but how much and at what cost? Games which are seriously bottlenecked on the HD are running in "lose mode" so to speak.

The HD is the slowest thing in the system (well, next to the optical drive), so it makes no sense for this to be a serious impedement in the game; the video, CPU, and RAM will matter much much more for these typically. However, you could hav a game that has a large disk image, and moreover, acceses that frequently enough for it to slow down your gaming. Typically, this would be "lose mode", but it could happen. If something like this is happening, then most likely it's accessing the optical drive, and you can get a big speed improvement by using something like Virtual Drive, which will let you copy that image to your hard drive. Bottom line -- if the HD is a serious factor, you should be able to determine this just by observing slow-downs in your program and the IDE light going on.

What are the costs / negative consequences of running RAID? First, it can be tricky to get your OS installed on a RAID array. You'll need to install the RAID drivers during the OS install. So you'll need to have a floppy drive and your RAID drivers on that floppy. Alternatively you could create a custom installation CD, but this is less trivial. Next, you can't use tools like Partition Magic, because they usually work best off floppy / CD-boot, and in these cases, don't recognize the RAID array. Moreover, they can fail if any of your drives are RAID'd. Next, any single drive failure will cause you to lose your entire array's data, and with 2 drives, you have twice the chance of failure. Not that huge with modern drives, but something. Next, the RAID tools / drivers are not as mature as the IDE drivers (and even those have been flakey at times), so these could be riskier. Next, write caching is important for drive performance, and turning that on, in a RAID 0 setting in particular, increases your chance for failure further. I wouldn't keep anything serious in such a setup without some backup. An easy backup is of course a simple single drive.. This is not a huge negative, because you can always benefit from a backup, but it is a somewhat more serious requirement when you have a risky setup. Finally, with a pure gaming system, you're more likely to get into risky areas -- overclocking, buggy games, buggy video drivers, buggy audio drivers, etc. It's not that drivers for games are more risky, just that they're pushed more than usual, and show their flaws. These are potential causes for system lockups, and when combined with write caching, can cause data / system corruption.

I agree that it wouldn't make sense to take the potential troubles of RAID in situations where they'll give marginal benefits.

All that said, I am a fan of RAID, and am continuing to deploy, use, and tune such systems where appropriate. Many applications have HD limitations as the most serious bottleneck. In these systems, RAID can be a great way to improve performance.

 

[Bobthelost]

Originally posted by: Madwand1
Going to dual Raid 0 will improve your perfomance over a single larger drive, but how much and at what cost? Games which are seriously bottlenecked on the HD are running in "lose mode" so to speak.

RAID has been shown time and time again to be no faster for gaming performance. Also running RAID for 2 smaller drives is almost always slower than using a single larger/faster single drive, for gaming.

The rest of your post is spot on though.