Promise Pegasus2 R4 Thunderbolt 2 on Windows 8.1

[Miles]

For those of you who wish to go with a thunderbolt storage solution using windows (I am currently using version 8.1), Promise Technology, Inc. now offers windows drivers for their Pegasus and Pegasus2 line of raid storage boxes.  The R4 (4 bay diskless version) can be purchased at the Apple store which as far as I know is the only place that sells it.  Due to the high cost of their versions with disks, I decided to go the diskless route and populate the bays myself with four HGST 4TB Deskstar NAS drives.  With raid 5 I end up with 10.91 TB of storage.  The unit automatically powers on and off with my pc and will shut the disks down if not being used, automatically powering them back up when an read/write request is made.  The admin software advises of any issues and I have found it quite easy to use.  The unit is temporarily on my desktop and I can hear the fan, but my hearing isn't what it should be.  I can also hear my pc fan, so I don't find the Pegasus2 fan annoying at all.  When working the drives can be heard.

A word of caution - I read somewhere that Promise won't support a unit populated with drives that are not on their approved list.  Their list is quite short and at last look only includes one 4 TB drive which is a Seagate desktop version (actually I own a couple of these drives which I have been using for backups).  I decided to go with the HGST NAS drives due to their perceived higher quality (advertised as 1 million hours MTBF), faster 7200 disk speed and the fact that they are NAS drives.  I had to call Promise during the installation (ended up my ASUS thunderbolt driver wasn't installed) and told them the drives I had installed and they didn't have any issue with it other than a customary warning that they are untested.  The support received was excellent and once the driver issue was resolved the technician stayed on the phone and showed me how to set up the raid and got things running (service a step beyond my expectation).  I realize I have taken a small risk with these drives, but so far it is running like a charm.

While 4 disks won't saturate a USB 3 connection let alone a thunderbolt 2 link, I wanted to try this technology and the R4 fit my budget.  So far I couldn't be happier.  If you want performance information, there are plenty of tests out there that would be far more informative than I can produce - just google search for them.  I found two items that a new user should be aware of - the windows instructions say you must have the latest firmware so make sure you update the unit with their software (quite easy to do, just look around for it).  The second item says to log on use your windows ID and password - this is incorrect and will not work so don't spend a lot of time on it.  Hopefully they update their instructions on this soon.

I hope this information is helpful to anyone thinking of going this route. 

[mvandenbos]

This is quite interesting to me. I had been looking at the pegasus2 diskless r4 but had been turned off by the restrictions on hard drive size and also the data interface being 3G vs 6G - as in the diskless system had lower specs than the complete solution. Has your experience borne any differences out? It would otherwise appear to be a good value solution for me with regards to storage for my rMBP which utilises thunderbolt 2.

With thanks


Mehdi

[mvandenbos]

Apologies I meant slower data transfer rate and lower cache


See this screen grab table from another (I've also seen it on the promise website)
http://www.luminous-landscape.com/forum/index.php?action=dlattach;topic=89995.0;attach=103176;image

[Miles]

Mehdi, the diskless version is only available on the Apple store site and as I understand it, was intended as a method for Apple users to be able to take drives out of their old system, plug them into the Pegasus, and the system would work.  I can't comment on this as I didn't go down this path. 

The link you provided references disks, their transfer rates and buffers and in particular, the older disks that can be transferred from an Apple product vs newer disks.  This data is inherent to the disks, not the Pegasus2 box.  If you populate the box with 6Gbs 64MB disks, I see no reason you should not get the performance expected.  I recommend you go to the Apple store and read the reviews for the diskless model.  You will find others have taken a path similar to mine with the disk of their choice and have been satisfied.

I'm certainly not an expert at this but after using the system for a few weeks now I can say I am satisfied.  I have tried both raid 5 and raid 10 with the system and both have performed flawlessly.  Check Apple's return policy (I believe 2 weeks and they pay the shipping as well) so you can give it a try basically risk free for a couple weeks.  I'm satisfied.

Another option that you may want to check out is Areca.  They sell a similar diskless thunderbolt1 box that also has a usb3 connection as well.  I believe they are a little more expensive however. 

If you have researched this, you understand that typical hard disks transfer rates on a 4 bay system will not saturate a thunberbolt 1 or 2 connection and probably won't saturate a usb3 connection.  With that said, in my research I have seen data where the Pegasus2 model outperforms the original Pegasus (both 6 disk system test).  Should you decide to populate the system with SSD's, I would then expect you would be beyond saturating a thunderbolt 1 connection and taking advantage of thunderbolt 2 connection speed.

Remember when comparing systems that the transfer rates quoted are for ideal setups with everything optimized in a perfect test case.  Your set up may or may not achieve the same transfer rates. 

I hope you find this helpful.
Miles   

[mvandenbos]

Miles many thanks for your thoughtful reply, it's been most helpful.

Regards

Mehdi