[awcopus]

The XServe RAID is marketed as being only compatible with Apple's "modules", which cost $508 for 250GB, 7200RPM, with an 8MB cache. Sounds a lot like the Western Digital drive, which sells for under $200 from good vendors like http://www.hypermicro.com/dept.asp?dept_id=06-001.

A quick look at the module itself reveals that it is just a container for a standard ATA drive. Clearly all of the cutting edge Apple proprietary stuff happens at and after the interface with the HD. So why would Apple make it hard or impossible for a dude who's dropped at least $6000 to own the RAID hardware to simply replace the drives themselves when they fail? Clearly the failure point is going to be the HD, and I've been there and seen that so I have extra 250GB WD Caviar drives lying around just in case. The idea of spending $500 instead of $200 when one of my drives fails is just, well, it's silly.

I need something with the XServe RAID's capabilities, but I'm easily offended by things like this. Have I misunderstood Apple's product? Any owners out there who have found that even though Apple doesn't officially sanction it, it is in fact easy enough to plop an appropriately AV-rated ATA drive like the WD Caviar 250GB one into Apple's modules and hum along?

Thanks in advance for any insights. Will contact Apple tomorrow, too, and share results of my investigation.

[tooki]

First, let me just point out that there is no longer a special category of AV drives, and hasn't been since, oh, 1997 or so.

Anyway, Apple claims that it tests the drives extensively before shipping them to make sure they are super-reliable.

tooki

[awcopus]

Tooki, with all due respect, there are drives that are sold as "AV-Rated". Presumably, such drives have been built to a spec that can handle typical video-streaming and video-editing better than drives that are not "AV-Rated." These drives are usually among a manufacturer's largest, have an 8MB cache, are sold with a longer warranty (3 years as opposed to 1), and they literally promote the drive as "AV-Rated" (that's their language, not something I made up).

Apple does not make these hard drives, and the most likely OEM is Wetern Digital, though Hitachi is a possible vendor. My point is simply that Apple's XServe RAID technology is one thing, and the hard drives they use are another thing. If the HD fails, one should be able to pop in a new HD that meets Apple's spec.... and I'm still looking into this to see if this is possible.... but it appears that Apple is saying a $200 HD failure requires a $508 replacement purchase.

[Scotttheking]

Originally posted by awcopus:
Tooki, with all due respect, there are drives that are sold as "AV-Rated". Presumably, such drives have been built to a spec that can handle typical video-streaming and video-editing better than drives that are not "AV-Rated." These drives are usually among a manufacturer's largest, have an 8MB cache, are sold with a longer warranty (3 years as opposed to 1), and they literally promote the drive as "AV-Rated" (that's their language, not something I made up).

I'm curious to see a link to these drives, and more specifically, a link that shows something other then a marketing label.

Apple does not make these hard drives, and the most likely OEM is Wetern Digital, though Hitachi is a possible vendor. My point is simply that Apple's XServe RAID technology is one thing, and the hard drives they use are another thing. If the HD fails, one should be able to pop in a new HD that meets Apple's spec.... and I'm still looking into this to see if this is possible.... but it appears that Apple is saying a $200 HD failure requires a $508 replacement purchase.

All OEMs do that. That's what warranties are for. That's also the reason many companies replace products once their warranties run out. Not because they are obsolete, but because it's a pain to replace parts on out of warranty products.

[tooki]

Originally posted by awcopus:
Tooki, with all due respect, there are drives that are sold as "AV-Rated". Presumably, such drives have been built to a spec that can handle typical video-streaming and video-editing better than drives that are not "AV-Rated." These drives are usually among a manufacturer's largest, have an 8MB cache, are sold with a longer warranty (3 years as opposed to 1), and they literally promote the drive as "AV-Rated" (that's their language, not something I made up).

With all due respect to you, I don't think you know what I am talking about.

In the past, there existed special AV drives. They weren't "AV-rated" (rated implies that they've been tested and found to be acceptable for that use). These were special versions of drives. When hard drives run (especially high-performance models), they get hot, and the heat causes thermal expansion of the platters, causing the position of data on the platter to no longer align with where the drive thought the data was! In order to continue functioning, drives back then would periodically perform "thermal recalibration", where the drive basically just figures out where everything is again. The problem was, this process took a fraction of a second, but was done on a repeating schedule, and it was a long enough glitch to interrupt writing or reading a continuous flow of audio or video. So the AV drive was born: it had the ability to defer the thermal recalibration until a more convenient time, so as to not cause a glitch in the data flow.

My point here is that AV drives were NOT special high-performance drives; they were no faster than the regular version.

But the distincion became obsolete when they started using "embedded servo" technology, where the drive is effectively being continuously calibrated.

Any drive nowadays calling itself "AV-rated" is just putting it on the box to make you think it's special. It's not. Nowadays, all the drives I've seen mentioned for video are BIG drives -- they're not saying that it's a special drive, just one that's big enough to hold lots of data, which is a convenient feature for video.

It'd be like the package for a blank CD saying "special MP3-rated disc" -- it means nothing, because EVERY blank CD will hold MP3's just fine.

tooki

[awcopus]

Originally posted by tooki:
With all due respect to you, I don't think you know what I am talking about.

In the past, there existed special AV drives. They weren't "AV-rated" (rated implies that they've been tested and found to be acceptable for that use). These were special versions of drives. When hard drives run (especially high-performance models), they get hot, and the heat causes thermal expansion of the platters, causing the position of data on the platter to no longer align with where the drive thought the data was! In order to continue functioning, drives back then would periodically perform "thermal recalibration", where the drive basically just figures out where everything is again. The problem was, this process took a fraction of a second, but was done on a repeating schedule, and it was a long enough glitch to interrupt writing or reading a continuous flow of audio or video. So the AV drive was born: it had the ability to defer the thermal recalibration until a more convenient time, so as to not cause a glitch in the data flow.

My point here is that AV drives were NOT special high-performance drives; they were no faster than the regular version.

But the distincion became obsolete when they started using "embedded servo" technology, where the drive is effectively being continuously calibrated.

Any drive nowadays calling itself "AV-rated" is just putting it on the box to make you think it's special. It's not. Nowadays, all the drives I've seen mentioned for video are BIG drives -- they're not saying that it's a special drive, just one that's big enough to hold lots of data, which is a convenient feature for video.

It'd be like the package for a blank CD saying "special MP3-rated disc" -- it means nothing, because EVERY blank CD will hold MP3's just fine.

tooki

Thank you for the history lesson.

I guess I plead guilty to falling victim to marketing hype. Not all 7200RPM drives are marketed as "AV-Rated", but the ones that are have the following in common:

1. As you said, they are big, usually 180 and up.
2. They have 8MB of cache.
3. They include an atypical 3 year manufacturer's warranty.
4. They all seem to run at 7200 RPM.

Apple makes a big deal about these specifications for its XServe RAID modules, which ONLY work with drives that have the above specs. My question continues to be, will the modules work with drives I buy and install... or do I have to chip in the additional $308 for Apple's. The answer so far is that there *probably* isn't a technical hurdle involved, but I would immediately void the warranty on the RAID if I installed my own drives in their modules. Also, the baseline XServe RAID ships with 4 modules, meaning Apple's proprietary drive holder containing an HD. Don't be fooled by all of those other empty slots... the only way to fill them is to buy more of Apple's "modules"... in other words, it's not like one could even test the idea of just installing off-the-shelf drives in the RAID because to get the tray that contains the drive, you have to shell out $508.

So, there it is.

[mousehouse]

and even when buying Apple modules, the Xserve RAID is a helluvalot cheaper than a comparable Sun or Dell solution

Wouldn't dying modules be covered by your Service Contract with Apple (applecare) within three years? After that period, since your out of warranty you would either extend your Service Contract or get rid of the whole Xserve anyway in any reasonable production environment -> you could try with the drives then...

[DVD Plaza]

Originally posted by awcopus:
My question continues to be, will the modules work with drives I buy and install... or do I have to chip in the additional $308 for Apple's. The answer so far is that there *probably* isn't a technical hurdle involved

To my knowledge, as well as the Apple technicians I have spoken with, there is no limitation - the ADMs simply contain a SATA drive.

Personally I've ordered extra ADMs with my G5 Xserve - HOWEVER when they arrive I'll be removing the SATA drives from the ADMs. Sitting here ready to install are three 10,000RPM SATA drives to take their place

If only it were possible to get hold of empty ADM sleds, would have saved a chunk of cash...