Which drive for RAID10?.

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The above two choices are the hard drives I am looking at. Please don't reply if you are not going to help. I am not asking people "Hey, what's the best 500GB HDD on the market!" I am asking people which of the HDD's I listed I should get, since one has lower RPM but has higher cache then the one with faster RPM.

Edit: Probably should have clarified that better in the OP, but like I said it is a poorly put together post.

DuckieHo: Hey!. How have you been, haven't seen you in a while. A google search for WD5000AADS benchmarks came up with nothing, I guess it isn't popular enough yet. I'll try searching deeper though.

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Ok!. How is it better then?.

Yeah. You don't know, if you did you would have posted it. Please leave my thread now since you were extremely rude. Bye bye!.

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I know, its sold out =/.

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I like WD.

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I already have the potential hard drives listed in the OP, I just need to know which of the two will be better in a webserver/MySQL environment on RAID10. One has a bigger cache, but lower RPM. The other one has higher RPM but a smaller cache. Cache is important for MySQL queries but I don't know if the lower RPM will actually decrease performance, and that is why I am asking on here since I don't know much about hard drives .

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Thanks, but I still think the higher cache would help a bit with MySQL queries. The lower RPM is a big turnoff though. +rep, since you actually tried helping .

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i just think your pretty ignorant when someone posts trying to offer sound advice, not my advice the other post above it, and you reply with a snotty message back. Frankly I'd be fairly satisfied if you didnt post again on this website, you clearly dont give a toss about what other people say, you seem to think you know it all, and heck you clearly do...hence your fabulous rep on this site etc.

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I have no idea what you are talking about when you said I replied with a snotty message back. Can you please quote said message?. As for the sound advice - what post?. So far nobody has actually answered my question with any sort of benchmark, link or proof that shows which drive is better then the other. Instead, I'm getting replies about other hard drives I should get instead of the ones in the OP.

I have no idea why your attacking me here. I don't really give a damn. If you have nothing constructive to add do not reply to my thread - the same should go for any other thread.

I actually do care what other people say, I just don't care for the people that completely ignore the OP and try telling me what else I should buy.

My low rep is because I visit this site maybe once every two or three months, I don't come here daily and post. Why does it even concern you?.

Many thanks for coming on here to insult and attack me. I hope you get banned off Overclock.net at some point when you do that to the wrong person and they don't like it either.

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Uh... Just to clarify.

RAID-10, depending on whether it's properly implemented or not, is actually a striped array composed of several RAID-1 volumes. It requires 4 disks, as you obviously know. Theoretically, it can withstand a 50% loss in drives, IF and ONLY IF, the failed drives are all on different RAID-1 arrays.

If one drive fails, the system should remain online with a very minimal loss in I/O performance. You should be able to simply replace the failed drive and the array will repair automatically by duplicating the data from the other member in the RAID-1 array.

I don't know how it's done in Linux, because I've never installed a software RAID-10 array, but in every iteration of NT Windows, a RAID-10 array, even those implemented with Intel ICHxR solutions, shows up as a single drive during Windows installation. Likewise with hardware iterations.

If the intention of the server is for SQL databases, your key points are going to be (1) spindle-count, (2) spindle-speed, (3) drive cache size, roughly in that order.

I would avoid any power-saving drives, WD Green included, because of the power-saving feature integrated into the drives. There have been known issues where the power-save features in the drive cause the RAID-1 array to drop out of sync and become degraded. There's actually nothing wrong with the drive, just that the data replication between the two drives in the RAID-1 array became far too out of sync. In a software RAID array, you're probably more likely to get a corruption of the entire RAID array.

To answer your question, because your spindle count isn't all that high (4 drives isn't all that much), you should then get drives that have high-spindle-speed - so 7200rpm sustained minimum. Drive cache would also be a slight-but-difficult-to-quantify-factor because you're lacking the dedicated support of a hardware RAID controller.

If I *had* to choose between the drives you provided, I'd go with the Caviar Blue drives in a heartbeat because I wouldn't trust a RAID array to run with Green drives. Given a third choice, I'd invest in WD Black drives, WD RAID-Edition (RE) Enterprise drives, Seagate 7200.12, or Seagate ES.2 Enterprise level drives.

With the Blues, if your motherboard supports it, maybe consider going with 6 drives in a RAID-10 to increase your spindle count. That's the conventional theory with RAID-10 on a hardware RAID controller. Honestly never implemented a software solution.

Pretty much what he said.

Avoid the Green drives - the high cache is irrelevant as you spend more time waiting for the platters to revolve to get the data you need anyway.

Cache does help with reads - the drive will cache all of the data in a track in case another I/O request wants data from earlier in the stripe. But there is not so much performance benefit from having more - if there was, do you think drive manufacturers would only fit 16 or 32MB when RAM is so cheap? Generally the amount of cache fitted is used because it is the amount required for that drive's controller & track size.

Seriously - if you intend to build a DB app with this number of spindles go with the Black recommendation. They are faster in all respects than the Blues, and much faster than the Greens. f you missed the recent Black deals then the 1TB Samsung F3s are also well worth considering - brand loyalty makes little sense in such a fast-paced market as IT IMO, although some will always swear by it.

The choice is yours.

I have to say though, I think your responses to some of the suggestions here have been less than polite though. Although you my only want to consider 2 disks, when neither of those choices are a good idea for the application you are using, suggesting another option IS the best thing to do. Just because you didn't ask for it does not make it wrong. Also remember that those posting do not owe you anything - they are only trying to help you for no personal gain. A little gratitude never goes amiss.

Just one other thing to consider. If you're building a MySQL database with these drives, your intention is (most probably) to leave the server running 24x7. Now, *supposedly* all drives can do that without a problem given sufficient cooling. But with that factor in mind, I'd *really* also consider getting WD Black drives because they also have a 5-year warranty.

I wouldn't be putting together the array *expecting* it to fail, but if a drive does fail, I know that my investment is going to be covered by the manufacturer for 5 years, instead of the normal 3. That alone would be worth the extra $10 or so for each drive...

Anyways, good luck with your build. Make sure you implement some form of SQL backup (to another disk, at the very least).