Caviar SE16 v. RE2

The SE16 is a very good drive meant for everyday use. The RE16 drive is the same drive with a few changes in the controller to have the drive behave better with hardware RAID controllers. Assuming you do not have a hardware RAID card installed and are using Apple's Disk Utility to create a software RAID 1 setup then save some money and buy the SE16 drives. You have no need for the RE16.

I run two SE16 500GB drives in a RAID 0 (software) configuration and it works like a charm!

Theres also a longer warranty with the RE2, 5 years vice 3 years for the SE16.

There is also another option I could throw in here, and that is the GP series (link below). They use less power, run cooler and have a 200 mbit/sec faster transfer from buffer to disk as opposed to the SE16 series.

Personally, i'm gonna go for a couple of those at some point in the near future, as these drives seem to be the most efficient and speediest you can get, without spending extortionate amounts of cash.

Western Digital GP Series

I was using some SE16s for testing, backups, as stripped RAID. Always worked, even though WD is darn clear about RE/RE2 being for RAID and non-RAID and the SE16 should not be used for RAID.

With Leopard I had some problems with Caviar SE16s, both internal and off Sonnet controller. Concatenated works, but not stripe. Tried with latest SoftRAID 3.6.6 beta and with Apple Disk Utility, didn't work with either (and Apple does make lots of these "under the hood" changes with new OS, and during the course of upgrades.

The price of RE2 now is what the SE16s use to cost, and 750GB SE16 is $189 now @ OWC.

It's odd that you are having problems with your SE16's under Apple Software RAID setup. Although the RE16 is clearly designed for RAID, the benefits are only for hardware controllers. It makes no difference in a software setup like that provided with Apple's disk utility.

When I upgraded to Leopard, I recreated my RAID-0 array and did a fresh install. No problems whatsoever (using two SE16's).

What are the problems you are having with making the RAID? Any error messages?

Not according to WD, and which is quoted on both OWC and Sonnet, for use of drives even in a non hardware raid such as Sonnet Tempo (I have the 2EP).

TLER or more? all I know is most people are willing to bend rules. With SCSI, and with huge investment in cables, terminators and such, it was a science as much as anything.

You know, with 10.4.4 I had been using a 15K drive along with a pair of 10K drives on a dual channel controller and I had to move the 15K drive off the channel the 10K drives were on. Never figured out why - just accepted it after trial and error.

And I spend a couple days talking to SoftRAID and doing some tests on my own, and for now - maybe it is in Sonnet's hands and it really needs firmware or drivers. Or 10.5.2. And SoftRAID, while 3.6.6b6 seems close to final, they are always learning more - (but I did try Apple and SoftRAID for stripping and Time Machine).

And I am willing to gamble that TM really taxes bandwidth differently (two FW drives active at same time can interfere with a TM backup operation).

Sometimes I fight and sometimes I go with the flow. I was going to hold off on Leopard until 10.5.3 - but gave in, but it is early in life cycle and it will improve and change. Just as 10.4.4 brought good changes to disk arbitration.

Actually, WD clearly states that the RE16 drives RAID advantages are for hardware controllers only. TLER is only advantageous with a hardware controller (and a high-end one, at that) that provides it's own error recovery procedures.

I'm kind of confused as to what exactly your problem is. What I have gathered is that you are using a third-party SATA or IDE host controller card and setting up a RAID on that. I doubt the drives have anything to do with that--it's probably more centered around drivers and firmware.

As for the OP's question, using the Mac Pro's SATA ports and setting up a software RAID with Disk Utility is 100% compatible with the SE16 drives.

According to your ,sig you aren't running Leopard, which we know 'broke' SoftRAID, changed support - and I always rebuild RAIDs when a new OS or revision comes out.

I did use internal set, too. Sorry, hard to list every single test.

WD has updated their information, supporting RE2 in non-RAID for desktop use, and still not supporting using SE16s.

Not an issue of internal or external, just wanted to add or show that there are more variables.

I've worked with SoftRAID support for 7 yrs and thousands of hours and dollars in the process.

Sorry that you want to pay more attention to my sig (which I forget to update on a regular basis) rather than my previous post:

"When I upgraded to Leopard, I recreated my RAID-0 array and did a fresh install. No problems whatsoever (using two SE16's). "

It works flawlessly. I don't know about SoftRAID, but the OP isn't talking about SoftRAID. Pretty sure he's just talking about Disk Utility software RAID setups.

I don't know where you are getting your information from WD but nowhere do they say the SE16 will not work (or work improperly) in a software RAID configuration. It's only for hardware RAID controllers that they recommend the use of RE16. That's the last time I'm gonna say it too.

Ignore him lol, he often goes off on weird tangents, but just confuses everybody else on the thread. 😉

You're absoutely right, the SE16 is fine for software raid setups and for small hardware raid setups, there is nothing that says it doesnt work for hardware raid either.
The RE2 series is an enterprise drive, which one would assume has gone through better quality control, and has been tweaked for large hardware raid setups, but is completely unnecessary in a Workstation.

Hi,

It does appear that they are 1 in the same. The WD7500KSRTL is the retail version of the WD7500AAKS. Pcmech forum post.


You are correct, the SE16 will work fine in a software raid, and cost you half as much. 🙂

And you usually are infallible! and install RAM any which way.

I know people don't WANT to play by rules or shave a few dollars savings. That is their own right and business. Just don't expect me to endorse it. But also, don't call me a fool.
===========

(2) Western Digital manufactures Desktop edition (WD Caviar, Caviar SE, Caviar SE16, and Raptor X) hard drives and Enterprise (RAID) Edition (WD RE, RE2, and Raptor) hard drives. Each type of hard drive is designed to work specifically in either a desktop computer environment, or connected to a RAID controller (hardware or software-based). If you intend to configure Western Digital drives in a RAID set, Sonnet and WD recommend using only their Enterprise edition hard drives. For more information, see this Western Digital FAQ.
http://eshop.macsales.com/item/Sonnet%20Technology/TSATAIIE2P/
FAQ
http://www.sonnettech.com/product/temposatae2p.html

RAID-specific time limited error recovery - Improves error handling coordination with RAID adapters and prevents drive fallout caused by extended drive error-recovery processes.

When an error is found on a desktop edition hard drive, the drive will enter into a deep recovery cycle to attempt to repair the error, recover the data from the problematic area, and then reallocate a dedicated area to replace the problematic area. This process can take up to 2 minutes depending on the severity of the issue. Most RAID controllers allow a very short amount of time for a hard drive to recover from an error. If a hard drive takes too long to complete this process, the drive will be dropped from the RAID array. Most RAID controllers allow from 7 to 15 seconds for error recovery before dropping a hard drive from an array. Western Digital does not recommend installing desktop edition hard drives in an enterprise environment (on a RAID controller).

Western Digital RAID edition hard drives have a feature called TLER (Time Limited Error Recovery) which stops the hard drive from entering into a deep recovery cycle. The hard drive will only spend 7 seconds to attempt to recover. This means that the hard drive will not be dropped from a RAID array.

If you install a RAID edition hard drive in a desktop computer, the computer system may report more errors than a normal desktop hard drive (due to the TLER feature). Western Digital does not recommend installing RAID edition hard drives into a desktop computer environment.

Specifications for the following Western Digital RAID edition Serial ATA hard drives.

WD1200SD, WD1600SD, WD2500SD, WD3200SD

WD4000YR

WD1600YS, WD2500YS, WD3200YS, WD4000YS, WD4000AAYS, WD4000ABYS, WD5000YS, WD5000AAYS, WD5000ABYS, WD5001ABYS, WD7500AYYS

this product is intended for server applications and is not recommended for use in desktop systems.
====================

+Topic got kicked around a lot over the last year.+
+ http://techreport.com/articles.x/10516/1+

Based on a Caviar SE16 750GB foundation that we already know delivers phenomenal performance with low noise levels, the latest RE2 benefits from tweaked firmware, RAID optimizations, more extensive reliability testing, and extended warranty coverage. Read on to see if those extras are enough to elevate this enterprise drive above not only its desktop counterpart, but also the fastest drives on the market.

Only upon consulting the drive's label can we discern between the SE16 and RE2. Drives with model number WD7500AYYS are RE2s, while those tagged with WD7500AAKS are Caviar SE16s.

Making an arbitrary distinction between drives that are mechanically identical seems unnecessary, but there's a method to Western Digital's madness here. One needs only to dig through the drives' specifications to get a hint at where the RE2 starts to differ from its desktop counterpart.

The RE2 manages to shave 1.3 milliseconds off the Caviar SE16's write seek time, for example. 1.3 milliseconds doesn't seem like much, but within the confines of a modern PC where bits flip at gigahertz clock speeds, it's actually quite a long time.

A more aggressive algorithm may make the RE2 seek a little faster, but that optimization is not without cost. The RE2's seek acoustics are at least a decibel higher than those of the SE16, suggesting Western Digital hasn't been shy about optimizing for performance at the expense of silence. That's a sensible trade-off for a drive like the RE2—a single decibel will easily be lost in the droning hum of most enterprise environments.

+In the past, Western Digital has warned against using drives with TLER in single-disk environments. However, no such warning accompanies the 750GB RE2, which WD says can be used all by its lonesome.+

http://techreport.com/articles.x/13253

Also, SE16 750GB - http://techreport.com/articles.x/12673

Oh do shut up, you're boring me now with your mindless drivel which you believe that you know.

I can copy and paste too:

"Never argue with a fool, they will lower you to their level and then beat you with experience."

Enough said.

"see this Western Digital FAQ." Thanks. That's actually a Sonnet FAQ.

And that only concerns people connecting to the Sonnet Tempo product which has nothing to do with using Apple's onboard SATA and software RAID setup which is exactly what the original poster is inquiring about.

Quit muddying the waters and confusing people with nonsense. Just because it applies to you does not mean it applies to the OP.