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Does anyone understand the differences in the Western Digital drives?

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JavaJones:
Hehe, glad to help. That line is from the Inquirer actually, but definitely funny. :D

As we've discussed before, I recommend against RAID for most people. The one exception to that is for high performance applications as even RAID5 can offer performance improvements over a single drive. Doing RAID is a "cheap" way to get high performance *and* high capacity. If all you need is a super fast drive of 100GB or less, go SSD though.

RAID for redundancy is really not that helpful for the home user. The only real reason to use it is for "high uptime" situations, which the home environment is seldom to be considered as IMO. In other words does it really matter in your home server if you have to take the machine down for a few hours to replace a drive and restore the data on it? In a business server environment yes it might matter, so you want the "hot swap" capability and the ability to keep running with data availability even after a drive fails. But for home users RAID is really just an added complexity and failure point IMO. Not to mention it's rather costly to do right. For an 8 drive array you're looking at $500+ just for a good controller, not to mention highly recommended battery backup (UPS for the whole machine will work and is the best option IMO), plus optional caching, etc. It's just not worth the complexity and cost IMO.

If big storage is your concern, go with single drives and avoid RAID headache.

- Oshyan

f0dder:
Velociraptor?  I have one, it's supposed to be fast.  My friend told me they're on the outs because of SSD, and he also said he did some tests and the Velociraptors were no faster than his regular 2 TB drives.-superboyac (February 17, 2011, 09:13 AM)
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Raptors are fast - but a bit too expensive for what you get.

I've got a pair of 75gig raptors, and those were very fast when they initially hit the market... but larger "standard" drives of today are a lot faster, at least with regards to sequential transfer speeds, because of the higher data density of those drives. It's the same story for the velociraptors.

Raptors are supposed to have better access times than the more "traditional" harddrives, though, especially for the 2.5" drives... but they're still molass-slow compared to SSDs. I wonder if the series will live on, if there's a point in being the middle point between ultra-speed SSDs with low capacity, and "slow" mechanical disks with large capacity - especially given the Raptors' high pricetag.

JavaJones: do you have any sensible information on the "dual cpu" thing that some WD drives have? I've seen it mentioned a few places, but haven't found anything on it, except it being used as fluffy marketing snake-oil.

4wd:
Possibly a couple of other things to mention, (or maybe not if no-one's bothered :) ), that differentiates Consumer from Enterprise:

Enterprise drives usually have higher IOPSw, (as you would hope if they're in a server environment), and a shorter error recovery time, (TLER).

Here's a WD document, (PDF), to explain the last bit: TLER

JavaJones: do you have any sensible information on the "dual cpu" thing that some WD drives have? I've seen it mentioned a few places, but haven't found anything on it, except it being used as fluffy marketing snake-oil.-f0dder (February 17, 2011, 05:00 PM)
--- End quote ---

This might help: Dual-Processor Hard Drives – All Good Or All Hype?

JavaJones:
Good extra info there 4wd. I don't see IOPS figures quoted on WDs site though, and I'm wondering just how big the difference can be. Judging by the Wikipedia article, SSDs can blow HDs away in IOPS anyway. The TLER issue is probably more the reason for the RAID-specific drives. I do wonder how important that really is as well because, as I said, I have 4 green drives operating in a RAID off a fairly decent RAID card for the last year with no problems (in a business environment). But reading more about all this now, I'm seeing that may not be considered a "proper" configuration. We're about to buy a new mirror server and I'm looking at what drives to buy; originally considering the AV-GPs, but after seeing Newegg's reviews on some of the enterprise stuff I'm concerned...

- Oshyan

4wd:
This Wikipedia articlew seems to indicate that you can switch the feature on/off in HDD firmware on even Consumer class drives because of the prevalence of chipset based RAID these days.

The article mentions a WD program to do it, WDTLER.EXE, and there's also WDIDLE.EXE if you want to change the Intellipark time.

I do wonder how important that really is as well because, as I said, I have 4 green drives operating in a RAID off a fairly decent RAID card for the last year with no problems (in a business environment).-JavaJones (February 18, 2011, 03:00 PM)
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It could be that the drives in the array have yet to experience an error severe enough that the RAID controllers error recovery is triggered.  Being a year old I would hope they're still reasonably reliable.

After having a search around various forums, it appears that WD, (don't know about Seagate ECR, Samsung CCTL, etc), have disabled the ability to toggle TLER in Consumer class drives from late 2009 - whether it's across the board, range or model specific I'm not sure.

Also that good RAID controllers seem to be able to handle Consumer class HDDs much better than cheaper RAID cards, I would also think any onboard based RAID controller is probably more tolerant of Consumer class drives.

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