2X 150GB VelociRaptors RAID0 vs. 2X 640GB WD Black RAID0

Unfortunately, they're way too expensive for me in terms of price and space ratio.

Do you think the slightly faster access time on the VRs are worth the extra $210? Also, which one would run quieter?

Vraptors are fast, and they are surprisingly quiet. I'd probably say that they get the edge in noise and power consumption compared to standard 7200rpm drives, and there would be a noticeable speed benefit. Is it $210 worth of speed benefit? That's somewhat questionable - I have a pair of 300 gig vraptors in raid 0 and love them, but it's definitely not the cheapest route to gaining speed.

Oh, and if you get velociraptors, get the 300gig version. The 150 gig isn't worth the cost per gb when you can get a 300GB for only $30 more or so.

From prices I've seen, the 300GB is $50 more so two of them would cost $100 more than two 150GBs. Not sure I really need all that space though unless Windows 7 ends up eating a lot of gigs. My current computer only has two 160gbs, with the first drive holding my OS, games, apps, etc. and the second drive my backup and videos. So far, I've only used half of that first drive.

Anyway, I went ahead and ordered the two Caviar Blacks. It fits my budget and from what I've read the difference in performance isn't huge and the Blacks have 32mb caches.

Good choice... I've run HDTune on several drives, including an older 150GB raptor. I wasted money on the raptor. I'm currently considering replacing it with a WD 640GB (black) as well as my older data drive. I've considered SSD's, but the MLC units seem to offer much lower 'bang for the buck' than the SLC units, and all have prices / GB that tend to make one choke. I've also considered SAS, but controllers (that I'd trust) are not cheap, and again price / GB is quite high. Not to mention that 15kRPM drives are not really quiet....

remember to backup your data (that goes for any important data you have, and reguarless of hdd setup/array)

As for RAID0 - i use it in all my main rigs - NEVER going back, helps everywhere - only RAID0 owners/users will agree here.

Backups I agree with. The question here, really, is given the current drives, would you pay the price for the difference between, say, raid0 on a pair of raptors vs. a pair of wd 640GN blacks vs a pair of SAS? Or a pair of SSD's? And money IS an object.

Problem is 15K server disks perform poorer than 10K velociraptors in desktop-oriented tasks. They do excel in multi-queue IOps performance for tasks like webserver/database/fileserver tasks, but in those tasks they get horridly surpassed by SSDs, so 15K disks are kind of without purpose IMO.

In fact, due to SSDs being so much faster, i believe HDDs will over time only exist to provide storage capacity - large data drives running at 5400rpm would be the only function left for mechanical disks to fill - any system drive ought to be an SSD. If you can't spend that money right now, then i'd opt to buy a single Velociraptor and save up money for an SSD.

In my opinion, there is little sense in buying an expensive i7 system with triple channel memory etc, if people are still relying on a mechanical disk to act as system drive. You won't have a fast computer, no matter what CPU you got. SSDs are expensive, but they provide real performance benefits they outweigh the 10-20% you usually get when choosing faster/better/more expensive hardware.

I'd gowith the Caviar blacks x4 raid 0. 2 of them will get about 192MB/s reads which is slower then OCZ SSDs @ 250MB/s

Im a SSD man myself, and I love em.