I asked this question in my other thread about HD system Configuration, but I think it may have been skimmed over. It is a totally different topic and should probably have its own thread.

I've noticed that a lot of people have rigs with two 36GB (or 74 GB) WD Raptors and a large drive (250-300GB) on the side (sounds like a Jurassic Park fast food order). What is the main benefit of this set up and are these set ups typically running a SATA RAID 0 (or 1+0) with Windows on them? Is it "OK" to run Windows off of a RAID, I had read that it was not "advisable". (though I don't always believe what I read)

LMK, please.

the point is that the raptor is a very fast drive. and with the windows install and the programs installed there it improves system performance. and with the larger drive as storage if you have a OS failure, you dont lose all the important info if you have to reformat. With the Raptor's they have a high spindle speed (10k RPM vs 7200 rpm for the other drives) and a low access time (somewhere in the area of >6 ms. with the larger/slower drives it is in the 12ms range. that may not sound like a lot but when you take into account the amount of file the drive is accessing then it puts it into perspective.

I run my XP Pro install off a pair of 74GB Raptors in RAID 0 with no problems. The only problems I have encountered were remembering to enable the motherboard settings for the SATA channels/controllers, and learning on my own how to set up the RAID array and install WinXP on them.

RAID 0 is reportedly faster than RAID 1, but the risk of catastrophic failure is higher. If one drive fails, the whole system will fail with RAID 0, since EVERYTHING is striped between the drives. With RAID 1, you have an exact image of the failed drive, nothing more lost than a few muttered curse words and a trip to the computer store for a replacement drive.

As for the third drive, my RAID 0 stripe is actually bigger than the storage drive I use (138GB vs 120), but the storage drive is in another computer, on my network. I save space on the stripe by downloading and installing programs to the Raptors, but then transferring/saving the downloaded .exe file to the storage drive.

I may even start tinkering around with other RAID setups at some point.

I've posted this link before, but this is why I'm not using two Raptors in RAID 0: AnandTech: Western Digital's Raptors in RAID-0: Are two drives better than one?

The article basically says that two Raptors in RAID 0, compared to a single Raptor:

1. Fail twice as often (since if either fails, the whole thing fails)
2. Costs twice as much
3. Gives a 20% or more performance increase in Pure HDD benchmarks.
4. Gives an unnoticable (-1% to +3%) difference in real-world performance.

So instead, I opted for a single 74GB Raptor as the boot drive, for the reasons Chrome mentioned.

For those who do run RAID, no disrespect is intended. I am curious to hear real people's measurements of how real-world load times compare to using a single drive.

EDIT: Corrected my erroneous statement on mirroring -- I'd mixed it up with RAID 1.

Quote: Originally Posted by FunkyFresh I've posted this link before, but this is why I'm not using two Raptors in RAID 0: AnandTech: Western Digital's Raptors in RAID-0: Are two drives better than one? The article basically says that two Raptors in RAID 0, compared to a single Raptor: Fail twice as often (since if either fails, the whole thing fails) Costs twice as much Yields no increase in storage -- you still have 74GB, since RAID 0 "mirrors" the drives. Gives a 20% or more performance increase in Pure HDD benchmarks. Gives an unnoticable (-1% to +3%) difference in real-world performance. So instead, I opted for a single 74GB Raptor as the boot drive, for the reasons Chrome mentioned. For those who do run RAID, no disrespect is intended. I am curious to hear real people's measurements of how real-world load times compare to using a single drive.

RAID 0 is a stripe, RAID 1 is a mirror. RAID 0 has no redundancy, if one drive fails you loose everything. RAID 1 has redundancy so if one drive fails you are still up and running.

Quote: Originally Posted by FeRaL RAID 0 is a stripe, RAID 1 is a mirror. RAID 0 has no redundancy, if one drive fails you loose everything. RAID 1 has redundancy so if one drive fails you are still up and running.

You're right, of course. My bad!

Quote: Originally Posted by FunkyFresh You're right, of course. My bad!

It's still expensive either way... Personally, I don't raid 0 anymore... The risk isnt worth the gains... If my PC goes down because of HDD failure, I'm looking at it staying down for a month or so as I don't have the same amount of time to work on my PC as I used to. Working full time, going to night classes at college three nights a week and being married takes up a majority of my time.

Quote: Originally Posted by FunkyFresh For those who do run RAID, no disrespect is intended. I am curious to hear real people's measurements of how real-world load times compare to using a single drive.

At the risk of dredging up a whole 'nother can o' worms... It just feels faster to me... And isn't that the most important measurement, Kyle?

Thanks for all the responses. From what I gather, a single 74GB Raptor with the OS and apps on it combined with a larger data drive would be optimal, unless I was concerned with redundancy.

Quote: Originally Posted by GrandpaNoob72 At the risk of dredging up a whole 'nother can o' worms... It just feels faster to me... And isn't that the most important measurement, Kyle?

ROFL! You get rep for that one...

Quote: Originally Posted by hartigan Thanks for all the responses. From what I gather, a single 74GB Raptor with the OS and apps on it combined with a larger data drive would be optimal, unless I was concerned with redundancy.

I just use a 36GB one (cost me less for my build) and ONLY use it for the OS and program files (of which I have heaps too!) to speed up the system (moved my "My documents" folder to a larger drive) and I have heaps of free space on it - may be worth considering

Quote: Originally Posted by Masterp may be worth considering

definitely worth considering.

I wasn't sure if it would have enough space, but if you're having no problems with space I'll keep that in mind.

Always nice to save $50 here and there when builiding a rig.

Quote: Originally Posted by hartigan definitely worth considering. I wasn't sure if it would have enough space, but if you're having no problems with space I'll keep that in mind. Always nice to save $50 here and there when builiding a rig.

Totally

36 GB's fine for the core program files - just make sure that everything else goes on your other drive - I must admit that it speeds up my startup and program boot times (am using the adobe video collection, there's a DEFINATE improvement there!)

As for redundancy, i just installed everything on the disk and ghosted it to DVD-RW - cheaper than building an array

Here's an article that you may find worth reading: Chipset Serial ATA and RAID performance compared: Whose arrays are faster?