Hands-On: Sans Digital TR4M-B 4-Bay SATA DAS Enclosure

Introduction

The Sans Digital TowerRAID TR4M-B  Enclosure is a Direct-Attached Storage (DAS) unit.  A DAS unit refers to a device that is directly attached to a server or workstation, without a network in between.  What this allows a WHS user, such as myself, to do is provide an opportunity to increase storage capacity beyond what is possible in the physical WHS computer.  In my case, I have plenty of bays to add additional drives, but my motherboard supports only 4 SATA on-board devices.  Using today’s 1TB drives, I would be nominally limited to 4TB’s of storage capacity.  Using one of Sans Digital’s optional host adapters, it is possible to create an array of TR4M-B devices, which use port replication, to obtain a total WHS capacity of 20TB using a JBOD configuration.  For those of you out there that must have the security of a RAID array, the Sans Digital device will allow you do this in a way that is transparent to WHS.  Very nice!

So who is Sans Digital?  From the Sans Digital website:

Sans Digital is a provider of high capacity, multi-functional advanced storage solutions. These storage units can be used in home offices, small and medium-sized businesses, video editing, data backup, surveillance systems and many other industries. Sans Digital’s products provide great solutions for companies and individuals across the world who need effective and reliable data storage systems.

Technology and Service Differentiation
Sans Digital offers storage products for RAID and bare-bone systems.  With technologically advanced products, Sans Digital ensures that the products will meet the customers’ needs.  By incorporating the latest technology, Sans Digital sets the standard in the storage industry.

Product and Service Innovation
Sans Digital offers products and services that are exclusively unique, which help customers improve their productivity. With over 10 years of experience offering complete storage solutions, Sans Digital’s products have come to be distinct with their unmatched technology.

Business Productivity Solutions
Every customer is different and Sans Digital recognizes that one size fits all storage solutions are unlikely to meet everyone’s requests. As a result, Sans Digital joined a wide variety of industry leaders to offer storage applications that are specific to various industries. This includes off-the-shelf or fully customized solutions.

Audiences
Sans Digital’s main customers include business and enterprise, government and education, creative professionals, as well as consumer and SOHO, which are reached through our Distributors, System Integrators, Value-Added-Resellers, and Dealers.

Sans Digital specializes in, but is not limited to, serving these vertical industries:
Audio-Video Editing, Data Backup, Surveillance Systems, Database Storage, Imaging, File Servers, and etc.

Specifications

Once again, from the Sans Digital website:

Overview

The TowerRAID TR4M-B is a compact RAID tower utilizing the latest SATA II port feature, where one single eSATA cable connects to four 3Gpps SATA II hard drives. Designed with easy installation in mind, the trayless TR4M-B allows instant installation by simply inserting the hard drives after opening the protective ventilating cover. It supports JBOD and Spanning modes for instant storage expansion. It also supports RAID 0, 1 0+1, 5, 5+spare via included software utility, for high performance and hard drive redundancy. The package includes a 2-port eSATA PCIe card at no additional cost, which allows the connection between two TR4M units (up to 8 hard drives) using only two cables. PCI/PCI-X options are also available.

Features

• Accesses four hard drives using only one cable.
• Host interface:
  • eSATA with Port Multiplier.
• Supports RAID 0, 1, 10, 5, 5+ spare, spanning and JBOD using bundles software utilities.
• Drive interface: 4 x 3.5″ SATA I / SATA II Hard drive.
• Supports the latest 1TB Hard Drive. Up to 4TB in storage capacity.
• Supports Windows 2000, XP, Vista, and Windows Server 2003.
• Supports MAC and Linux. (Please note that the host adapter card is based on Silicon Image chipset, which currently only support up to MAC OS 10.5.1 by Silicon Image.)

Specifications

Available Models

Optional Accessories

• HA-SAN-4ESPCIX – PCI-X eSATA 4 Port Host Adapter
• Silicon Image SIL3124.
• Supports SATA II, up to 3.0Gb/s.
• Supports NCQ and LCQ.

• HA-DAT-4ESPCIE – Four eSTATA Ports PCI-Express (x8) Host Adapter
• Fully compliant with SATA I and SATA II.
• Supports Serial ATA Generation 2 transfer rate of 3.0 Gbps.
  

What’s In the Box 

The TR4M-B|TR4M comes in a box with pictures of the main components inside, as well as as list a features, specifications and hardware connections on the various sides.  The TR4M-B has the black enclosure while the TR4M has the silver enclosure.  The box even includes a nice carrying handle.

When you open the box, the first item you will find inside is small placard that provides general contact information as well as technical contact information.  This is a nice touch that should be the first item that any buyer should see with any consumer device.  The box that you see first inside contains the ESATA card, DVD disk, and other accessories for the unit.

Burrowing down the past this box, you will find the the actual DAS enclosure and 4 small boxes tightly packaged around this enclosure.  These boxes contain the physical hard drives.  According to Sans Digital:

The hard drive bundles are not prepackaged at the factory to prevent hardware damage during shipment.  They are all freshly installed and tested by our technical team.  Once the testing has been completed, the hard drives are then taken out and packaged separately for the same reason.  This is usually the case with units that require more than 2 hard drives, because with the weight of these drives, many things could go wrong during shipping.  If the units come with hard drive trays, the hard drives are left within the trays when repackaged, so the customers simply need to plug the trays back into the unit.  All of this is to ensure our customers receive thoroughly tested units, requiring as little installation as possible, so they could have the units up and running right away.

When you first see the unopened box, one must think that the TR4M-B is quite large.  Looks can deceiving, however.  The physical TR4M-B enclosure measures only 5.3″W x 7.1″H x 10.0″D.  It is quite small and very unobtrusive.  And did I mention that is has a very nice shiny black casing?

What is shown below are the items included in the accessory box.  eSATA card, low profile bracket for the card, power cord, eSATA cable, DVD containing drivers and manuals, and a small bag containing the screws to attach the hard drives inside the enclosure.

The eSATA card and bracket are shown below after removal from their protective anti-static bag.  The card itself contains 2 external eSATA ports.  The chipset is a common Silicon Images SiI 3132 controller.

Installation

As stated by Sans Digital, installation of the hard drives is a relatively simple process.  Remove 3 thumb screws from the back of enclosure, lift off the top cover, open the mesh front door, and slide in the drives.  Secure the drives with the included thumb screws, reassemble the cover, and the unit is ready to hook up to your computer

One of the advertised features of the TR4M-B device is hot-swap capability.  Installing the hard drives as indicated above eliminates this capability.  I posed the question to Sans Digital regarding this installation procedure and their response was:

Our customers usually take advantage of the hotswap feature by simply sliding the hard drives into the unit from the front without taking off the top case.  However, if the unit needs to be frequently moved around, we recommend the hard drive to be secured by screws to stop them from sliding out.

So, if one does not intend to move the unit after intial placement, all you need to do is open the front door and slide in the hard drives.  One door, 4 hard drives.  Simple hot-swap.

The picture below simply shows the inside layout of the enclosure prior to hard drive installation.  You can see the backplane and just behind that is the 80mm exhaust fan.

This is shot of the back of the enclosure.  Located on the back of the unit are the power connector and switch, power converter switch, exhaust fan, and eSATA port.  The Sans Digital unit use Port Multiplier technology which requires just one eSATA connector between this unit and the host computer.

Just a couple of pictures of the TR4M-B unit sitting on top of my WHS CoolerMaster case.  The enclosure finishes match perfectly!  These 2 pictures give you and idea of the size of the unit.  Very small and unobtrusive.  If desired, you could easily stuff it out of the way in a corner.  But why do that?  It simply begs to be displayed up close and personal.

 

 

I reassembled the WHS computer and installed the drivers.  I pointed the OS to the appropriate folder on the included DVD.  WHS also checked the Microsoft web update for any updated drivers.  In the end, driver installation was quite painless.

 

Once the drivers were installed, I simply plugged in the power cord and eSATA cable in the appropriate places.  I had instant increased hard disk storage space!  The following 2 pictures gives you a indication how the LED lights work.  The lights on the right indicate power and the host indicator status.  The 4 lights on the left indicate hard drive status.  The second picture shows the change in disk status as a hard drive is being accessed.

 

And for those who like a nice LED fan, simply turn the enclosure around.  The exhaust fan produces a nice soft blue hue from the LED’s.  I can take or leave LED fans, but it is nice to be able to have an easy way to check for a correctly operating fan.  And for you noise fanatics, of which I have to include myself, the fan is very quiet!  I turned off all the noise producing devices in the area, with the exception of the Sans Digital unit.  I could barely hear it from less than 3 feet away.  I would call it a near-silent fan.

Total time to get this point?  It is rather difficult for me to be definitive, as I was documenting all this as I went through the process.  I would estimate that the total time from initial opening of the package to the point where I took the above pictures would be less than 30 minutes.  At least for those that are at ease putting this this type of hardware together.  It also depends on how much documentation you wish to read prior to getting the unit up and running.

Performance

Sam Wood makes a very nice add-in for WHS aptly named Windows Home Server Disk Management.  With this nifty add-in, I was able to take a very definitive snapshot of WHS disk array, as can be seen below.

I clicked on the WHS Server Storage tab, which provided an alternate view of the storage array.

So, now for the real question.  How does the Sans Digital device perform?  Originally, I was going to use ATTO Disk Benchmark software, but it only recognizes logical drives, not physical drives.  As I wanted to compare drives in my WHS array to the Sans Digital drives, I was forced to use the HD Tach Disk Bench software.  While slightly outdated, it does recognize physical drives, which ATTO does not.

I first tested my WHS boot disk, which is a newer production model than any of the other drives.  I also ran a test on a WD1600JS disk, which just so happens to be the same model as the drives Sans Digital sent me for this review.  That was a nice coincidence.  I ran my initial tests with the Sans Digital drives outside of the WHS drive pool.  The following comparison chart shows my WD5000AAKS against the one of the Sans Digital WD1600JS drives.  As expected, the later generation 500GB drive beat the 160GB drive easily.  Of course, I expected this.

I than ran a test comparing my Seagate ST33206 320GB drive to Sans Digital WD1600JS.  Once again, the newer generation drive easily beat the older generation drive.  One item that surprised me somewhat is that the Seagate drive ate up CPU cycles.  Must be one the reasons why these drives were selling so cheaply when I picked this one up.

Since I had a hard drive model of the same type in my WHS, a more fair test would be to compare these drives.  The following picture provides this comparison.  It was nice to see that the performance numbers were nearly identical.  Whatever overhead that is required to attach this DAS unit to the host computer has minimal effect, if any, on performance.  With the exception of Burst Speed which was considerably higher on the internal hard drive.

I emailed Sans Digital and asked them if they could provide some insight into this difference.  Their response:

The Burst Speed is slightly delayed when the hard drive is in the unit because the data must be processed by the chipset of the Port-Multiplier feature. The Port Multiplier allows 4 hard drives to be accessed by one cable, and therefore the chipset scans all four connections when processing data (even if only 1 hard drive is present).  While when the hard drive is in the computer, data is being accessed directly without going through additional chipsets.

Is Burst Speed important for a Windows Home Server?  Possibly, but I doubt anyone would see a real difference in actual use.  Regardless, I would rather have the single eSATA cable connection.

As a last benchmark, I simply compared 2 of the Sans Digital drives, just to make sure that they ran about the same.  As can be seen below, the numbers were almost identical.

It was now time to add the Sans Digital drives the WHS array.  I initially added these drives in a JBOD configuration.

I ran a test on one of the Sans Digital drives and compared it to the same drive when it was outside the WHS array.  As can be seen, about the only item that changed was Random Access time.  As this changed somewhat from test to test with various WD1600JS drives, I considered this to be a non-factor in real-life performance.

It was at this point that I decided to let the unit sit there in the array and do quietly do what hard drives do.  Unfortunately, WHS’s drive balancing has changed significantly with PP1.  I could probably let it sit there for a month or so without any data being put on.  Most, if not all, of the data I have on my WHS is backed up in some form or another.  As a result, I have never turned on folder duplication.  It was about time to try out this feature, in an effort to make use of this increased storage capacity.  As I turned on duplication of 500Gb’s worth of shared folder data, the transfer rate that can be seen in Windows Home Server Disk Management on the Sans Digital drives immediately took off like a rocket.  It was quite interesting to watch the LED light show that the Sans Digital unit started to display.  It kind of reminded me of a one of those display consoles in the original Star Trek episodes!  The following picture shows how WHS spread Folder Duplication over the Sans Digital disk array.

One piece of technology that I have on my WHS is a Crystalfontz LCD display.  I use this item to display several key performance factors of my WHS.  While the folder duplication was occurring, I took some photos of a CFA-635 in action.  What I saw was very little difference in CPU usage during this period.  Most of the CPU usage that occurs on my WHS is from my BOINC program, which can be fairly CPU intensive.  The CPU usage that I saw was in line with what I have seen in the past without heavy disk usage and/or without the Sans Digital unit.

 

Please note that I took the above pictures in a dimly lit room, so that the displays can actually be seen in the pictures.

It was now time to dismantle the JBOD setup and check out the RAID functionality of the TR4M-B unit.  Setting up a RAID array is a relatively straightforward process.  Simply insert the supplied DVD into your drive, locate (sataraid_utility folder) and execute the SATA install file.  I used the Windows XP 2000 installer.  The following pictures document the install process.

 

 

 

Once the RAID utility program has been installed, execute it and you are presented with the following screen.

Under the RAID Group menu, you will find the Create RAID Group item.  Opening that brings you the following screen.

Select your RAID options and create your array.

 

The array I created is a RAID 5 array.  If you look close, there is one item you may have noticed that created a problem for me the first time I created the array.  You will notice a pull-down menu item: Capacity.  The first time I went through this task, I did not scroll far enough down the menu.  All I saw was 1GB, 2GB, etc. options.  It is only at the bottom of the menu did I eventually find a “Max” option.  I would suggest to Sans Digital that this option be the first item in the list, not the last.

Once I straightened out this anomaly, I went to Windows Computer Management, opened the Disk Management menu and prepared the disk for use in WHS.

 

 

 

 

Please note that I took these pictures before I realized that I had made the aforementioned disk capacity error.  If done correctly, I promise that you get much better results!

Once I had successfully setup the RAID array and prepared it for use the operating system, it was time to see how it worked with the WHS Storage Array.  If you set it up correctly, you will see the RAID array added instantly to the WHS Console Storage Array. 

I followed the same procedure, using HD Tach, I had previously used by testing the Sans Digital drives outside the WHS and as part of the pool.  The following picture compares the RAID array to one of the drives in the JBOD array.

The following picture compares the RAID array outside the the WHS drive pool and as part of it.

From the above pictures, one can come to 2 conclusions.

1. As with a JBOD configuration, there is minimal difference between drive performance inside or outside of the WHS pool.
2. There is a significant penalty for using a RAID 5 array.  Both in performance and available drive space.

I do need to stress that the penalty for a RAID 5 array is not a Sans Digital problem.  There are 4 basic types of RAID array available, RAID 0, RAID 1, RAID1+0, and RAID 5.  RAID 5 provides the best balance of capacity, speed, and failure recovery.  The key word is balance.  In the end, I am happy to report that if you desire to use RAID in a WHS, it is rather painless to implement using the Sans Digital device.

Costs and Conclusion

The TR4M-B can be configured anywhere from the base unit without drives all the way up to (4) 1TB drives. One can spend anywhere from $295 to over $1200 for a fully loaded unit with the optional 4-port PCIe card.  I took a quick look at Newegg to see what the street price of the base unit might be: approximately $225 shipped.  That is a very nice price for what you get: a 4 HD enclosure, power supply, JBOD to RAID 5 capability, port replication, hotswap capability, and a PCIe eSATA adapter.  The chart below provides you with the list price breakdown for the various versions.

With the cost of hard disks dropping on a weekly (or daily) basis, it would seem to be a little difficult to justify the cost of a fully configured case at this time.  That is one area that manufacturers are at a disadvantage.  They can’t/won’t adjust their Retail Price based on a fluctuating component market.  Sans Digital’s response to this observation was:

Sans Digital uses Seagate or Western Digital for hard drive bundles. The pricing of the HDD bundles are slightly higher because they must be tested after the hard drives are installed, before they are released to customers. It benefits the end-users by saving them a lot of installation and setup time. One could also purchase the enclosures and install the hard drives himself.

One question that you may have regarding the TR4M-B device is what is the maximum storage capacity of the unit?  What is noted below is my question to Sans Digital and their response.

If one purchases their own HD’s, is the maximum capacity 1TB per bay, or will these units accept the 1.5TB units that are coming on the market at this time?

Because the 1.5TB is not readily available, the compatibility is yet to be confirmed. We do not suspect there to be any problems because they are based on the same SATA technology.  There was no compatibility issue when the HDDs went from 750GB to 1TB.  The written specs will remain at 1TB, until the 1.5 has been tested and confirmed.

Pros

• Easy to setup.  0 maintenance after initial setup
• Direct Attached Storage is a perfect solution to increase storage capacity on a WHS
• Very reasonable price for the base unit
• High capacity four drive enclosure
• Trayless construction (my personal preference)
• RAID 0, 1, 10, 5, 5+spare, spanning and JBOD support
• hotswap capability
• Port replication requires just one eSATA connector
• Includes a 2-port PCIe eSATA card
• Extremely quiet
• Quality construction
• Small footprint
• Tool-less construction

Cons

• Can get rather expensive if one buys the unit with Hard Drives
• Port replication degrades Burst Speed performance
• Hotswap removal feature is for stationary units

Overall, I was very impressed with the Sans Digital TR4M-B DAS device.  The pros noted above pretty much says it all.  The cons that I noted are quite minor.  Would I recommend it?  Without hesitation.  If you are out of SATA ports on your motherboard or out of storage bays in your case, this device should be on your short list of devices to consider to increase your storage capacity.

I would like to thank Sans Digital for sending me this sample for review.