AMUG WiebeTech SilverSATA II Dual Bay eSATA Enclosure Review

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March 15, 2006

Dual Bay eSATA Enclosure & Disk Cloner
A review of the WiebeTech SilverSATA II Dual Bay SATA Enclosure (SISII-0)
By Arthur Whalem

WiebeTech is shipping the SilverSATA II dual bay external eSATA Serial ATA enclosure model SISII-0 ($379.95). The SilverSATA II has the ability to display both hard drives mounted in it as a single volume using its internal hardware RAID (Redundant Array of Independent Disks) or it can mirror the hard drives and display the master drive on the desktop. The hardware RAID supports RAID 0 (Stripe mode) or RAID 1 (Mirror mode).

The body of the SilverSATA II enclosure is a very nice silver anodized aluminum design with curved edges. It has a small 2" by .65" LCD that displays the status of the hard drives when the enclosure is turned on and allows you to change hardware RAID types as well as monitor fan activity. The SilverSATA II uses an 8032 Microprocessor RAID ASIC chip to power its internal hardware RAID capabilities. The enclosures dimensions are 4.9" wide, 4.1" high and 8" deep. It weighs almost 4 pounds empty and once you install two 3.5" SATA hard drives into the WiebeTech SilverSATA II enclosure it weighs a little over 6 pounds. The SilverSATA II has a 70 watt switching power supply and provides both a 40mm and a 30mm cooling fan which are installed in the rear of the enclosure. Two 3.5" removable hot swap hard drive trays are used to mount each hard drive inside the enclosure. Each drive tray has a drive activity light mounted on the right side. These same drive trays can also be utilized in the SilverSATA I and the SilverSATA V enclosures.

You provide your own SATA hard drives with the model SISII-0 configuration. However, WiebeTech also sells the SilverSATA II enclosure with SATA hard drives pre-installed. Configurations available include a 320GB unit with two 160GB drives (SISII-320) for $625.95, a 500GB unit with two 250GB drives (SISII-500) for $737.95, an 800GB unit with two 400GB drives (SISII-800) for $1135.95 and a 1TB unit with two 500GB hard drives (SISII-1000) for $1331.95. The SilverSATA family of enclosures includes the SilverSATA II which is the subject of this article along with the single bay SilverSATA I and the SilverSATA V.

SilverSATA Family Photo

The SilverSATA II enclosure shown on the left in the image above is designed to be utilized with photo imaging, multimedia, servers or any activity where creating an exact mirror copy of the data stored on a SATA hard drive is desirable. The SilverSATA II has the ability to clone SATA 3.5" desktop hard drives using an internal hardware sector copy procedure. The SilverSATA II system is as much of a stand-alone hard drive copy station as an eSATA enclosure. It can even duplicate bootable hard drives. The duplication/clone process can be done without the use of a computer saving energy and freeing up the computer for other uses.

System Requirements
Macintosh OS X, Windows 2K, XP.
Requires no drivers.
Can be used with SATA PCIe, SATA PCI-X cards or USB 2.0 connections.
Requires up to two SATA 3.5" hard drives.

Connections
The WiebeTech SilverSATA II dual bay enclosure has an internal 70 watt switching power supply. You simply plug the power cord into the rear of the enclosure and use the power switch on the back to turn on the SATA hard drives. Both a USB 2.0 connection and a SATA connection are provided. However, you can only use one of the data connections at a time. A single cable is used for connecting the enclosure to your computer even though you may have two SATA hard drives installed. The SilverSATA II internal hardware RAID will only display one icon on your desktop, whether the enclosure is configured as RAID1 (mirror) or RAID0 (striped). There is no single drive mode that can display two hard drives on the desktop.

RAID1 mirroring from one hard drive to another using the SilverSATA II is very fast. RAID0 striping also works, but in my tests it was about 25% slower than when writing data using a typical dual drive, two cable striped RAID set enclosure like the FirmTek SeriTek/1EN2. The key feature of the SilverSATA II is the ability to sector copy SATA hard drives from one bay to the other or to create an instant copy of your data using RAID1. While it is nice that the SilverSATA II has the flexibility to be used in a striped RAID configuration, its best feature is fault-tolerance and data redundancy. Using the SilverSATA II with two hard drives in RAID1 mode provides an exact duplicate copy of the data on your hard drive. The duplicate hard drive can be removed for use in another device while a new hard drive is inserted to make another backup copy. Easy access to your data with full backup capability is what the SilverSATA II is all about.

An RS232 port is provided on the back of the SilverSATA II enclosure. You can connect an RS232 cable between a PC and the SilverSATA II and use the provided RAIDGuide Manager PC software to upgrade firmware, monitor the internal fans and display the enclosures temperature reading.

The RAIDGuide Manager software version 1.28.1.7 that was used with this review allows you to monitor and log many different SilverSATA II activities including connections, system mode, hard drive failure, hard drive insertion identity and can be setup to send an email to the administrator should there be a hard drive failure. While most Macintosh users may not use this feature, it does add some interesting self monitoring capabilities to the SilverSATA II when paired with a PC. The RAIDGuide Manager PC software solely uses the RS232 port for monitoring the SilverSATA II. As such, the SilverSATA II enclosure could be mounted on a Macintosh computer using the eSATA or USB 2.0 port for data sharing and a PC could be used via the RS232 port whenever the user wanted to monitor the enclosure. While I would like to see the RAIDGuide Manager functions work with a Macintosh, they really are not needed for normal every day enclosure operations.

Interface
Removing a SilverSATA II hot swap hard drive tray is as easy as inserting the tip of a small white key into the drive eject hole on the right side of each tray. Once the key is inserted, the hard drive tray handle pops open and allows you to easily slide the hard drive out of the SilverSATA II enclosure. The WiebeTech SilverSATA II enclosure provides hard drive activity lights on the right side of each drive tray. When the hard drive is accessing data a blue light blinks. In addition, the "ENT" button can be pushed on the front of the enclosure to display the system temperature on the blue LED display. Pushing the up arrow button while in this mode will also display the RPM speeds of each system fan. Pushing the "ESC" button or waiting 10 seconds resets the LCD display back to displaying the status of the hard drives. The SilverSATA II provides a considerable amount of information using its LCD, including whether it is in RAID1 or RAID0 mode.

RAID1 - Automatic Duplication
The SilverSATA II uses an automatic duplication process while in RAID1 (mirror mode). If you have a single SATA hard drive installed in the enclosure and turn the enclosure on, it will identify that hard drive as your master. Inserting a second hard disk into the enclosure will cause the SilverSATA II to automatically duplicate the existing master hard drive to the new drive you just inserted. This will erase all data that might have been on the second hard drive and replace it with a duplicate sector by sector copy of the master drive. There is no warning that requires you to push a button to start the duplication, it just starts duplicating within a few seconds after installing a second hard drive into the SilverSATA II enclosure.

As long as you understand this function, the automatic duplication mode of the SilverSATA II enclosure is an awesome feature. However, if someone simply inserts a second SATA hard drive in the SilverSATA II while in RAID1 mode thinking that it will mount on the desktop, they are in for a surprise. More than likely the enclosure will immediately start to replace their data with that of the master drive in the enclosure. As a result, use of the SilverSATA II should be reserved for those that know how the enclosure works. Those unfamiliar with the automatic duplication function of the SilverSATA II can easily lose data.

You can use the SilverSATA II in RAID1 (mirror mode) as a hot swap drive bay, but you will need to be sure that just one SATA hard drive is in the enclosure for this purpose. Once you insert a second drive it starts the automatic duplication process. The real advantage of the SilverSATA II is data redundancy and fault tolerance. It provides an exact mirror copy of the master drive on a second easily removable SATA hard drive. You simply leave the master in the enclosure, turn it on and then after a few seconds insert a second drive. The SilverSATA II will begin duplicating the master. In addition, it will keep the backup current in real-time as long as the second drive stays in the enclosure. If you want to use the duplicate of your master on another computer you can eject it. If you want a second backup copy, you can insert another hard drive into the enclosure and it will immediately start rebuilding another backup copy. The SilverSATA II can do all of this either with or without a computer connected to it. The enclosure is really a SATA disk duplicating machine that can also be used as a SATA enclosure.

Possible Uses
Provide an automatic backup solution for any computer.
Duplicating identical bootable drives for a computer lab.
Creating a duplicate copy of any SATA hard drive.
Clone an old drive to a new drive for easy HD upgrades.
Duplicate a master hard drive for several users.
Create a duplicate of your master for off site use.
Sector copy any Mac or PC hard drive for any purpose.

Limitations
There are a few rules while in RAID1 mode that SilverSATA II users will need to know. When using RAID1 (mirror mode) identical model hard drives work best. If not identical, then the backup hard drive has to be larger than the master. A smaller drive will not work, even if it exceeds the size of the data that needs to be backed up. The automatic duplication function uses a sector copy. It writes every block on disk 1 to disk 2, even when there is no data. That means that the time to create a duplicate backup is determined by the size of the disk, not the size of the data to be backed up. Using two 160GB Hitachi SATA hard drives as an example, takes 65 minutes to create a complete sector copy. This is true whether the master drive is almost empty or totally full. The SilverSATA II LCD displays what percentage of the copy process is complete as it proceeds. This allows the user to easily monitor how the duplication process is progressing. As long as the user remembers these basic rules the SilverSATA II works very well in RAID1 mode.

RAID0 (Striped Mode)
As the SilverSATA II costs considerably more than a standard dual bay SATA enclosure, most users will not purchase this enclosure as a RAID0 solution. However, the SilverSATA II does have the flexibility to create a single hard drive volume using two SATA hard drives when using RAID0 mode. The down side to this usage is that the SilverSATA II loses its backup features in this configuration. In addition, it operates a little slower in RAID0 than if you used a standard dual bay SATA enclosure and created the striped RAID set using Disk Utility. The other limitation is that if you want to use the enclosure for disk duplication you have to reset the SilverSATA II to RAID1. Doing so erases the data on the RAID0 configured hard drives that are currently inserted in the enclosure.

Limitations
When using RAID0 (striped mode) identical model hard drives work best. If not identical, then the smallest hard drive will be used X2 to determine the size of the striped RAID set. Returning to RAID1 requires that you backup any data on the striped RAID that you wish to keep. The hard drives are erased when changing to a RAID1 configuration.

Compatibility
The design of the WiebeTech SilverSATA II enclosure does not allow for individual SATA hard drive connections. The internal hardware RAID of the SilverSATA II accepts up to two SATA hard drives but only requires one SATA or USB 2.0 port to connect the enclosure to a computer.

The chipset of the SilverSATA II is compatible with every USB 2.0 port on a Macintosh or a PC that I have tried without requiring the installation of a driver. However, SATA connections with the SilverSATA II enclosure do not work with host adapters that utilize the Intel 31244 PCI-X to Serial ATA controller chip. A SilverSATA II compatibility list of several Macintosh SATA host adapters is provided below.

SilverSATA II Host Adapter Compatibility Chart

Card	Compatible	Boot	Speed	Hot Swap	Ports	Configuration
FirmTek SeriTek/1S2	Yes	Yes	32-bit PCI	No	2	Internal "L" Type
FirmTek SeriTek/1 SE2	Yes	Yes	32-bit PCI	Yes	2	External "L" Type
FirmTek SeriTek/1eVE4	No	Yes	64-bit PCI-X	Yes	4	External eSATA
FirmTek SeriTek/1VE4	No	Yes	64-bit PCI-X	Yes	4	External "L" Type
FirmTek SeriTek/1V4	No	Yes	64-bit PCI-X	No	4	Internal "L" Type
FirmTek SeriTek/1VE2+2	No	Yes	64-bit PCI-X	Yes	4	Int/Ext "L" Type
Sonnet Tempo-X 4+4	Yes	No	64-bit PCI-X	Yes	8	Int "L"/Ext eSATA
Sonnet Tempo-X 8	Yes	No	64-bit PCI-X	Yes	8	External eSATA
Sonnet Tempo E4i	Yes but no sleep support	No	64-bit PCIe	Yes	4	Internal "L" Type
Sonnet Tempo E4P	Yes but no sleep support	No	64-bit PCIe	Yes	4	External eSATA

As you can see in the chart above the FirmTek SeriTek/1SE2 is an external two port SATA host adapter that provides boot capability with the SilverSATA II. The Sonnet Tempo-X 4+4 and 8 cards work using firmware 1.2, but do not provide boot capability. The FirmTek 1eVE4, 1VE4, 1V4 and 1VE2+2 will not mount hard drives mounted in the SilverSATA II enclosure.

Backplane Mounting
If you remove the two hard drive trays in the front of the SilverSATA II and look inside the enclosure you will see the backplane mounting board shown below.

As the hard drive trays slide into the SilverSATA II enclosure, the SATA connections on the back of the hard drives connect directly to the backplane board. A SATA port on the rear of the circuit board is used to plug a SATA cable into the SilverSATA II enclosure. No additional SATA cables are required inside the enclosure.

Inside
If you remove the six small screws on the bottom of the SilverSATA II, you can pull off the aluminum body and view the internal design. The power supply sits above the hard drive bays along with the LCD display.

An 8032 Microprocessor RAID ASIC chip powers the logic of the SilverSATA II. In addition, the SATA controller chipset mounted on the rear backplane board handles the internal hardware RAID configuration. The hard drive bays have their own compartment in the SilverSATA II, separated by a steel frame.

Cooling
The SilverSATA II internal hardware RAID controller does not pass SMART temperature data to the Macintosh. As a result, Hardware Monitor cannot display the temperature of the hard drives installed in the SilverSATA II. However, the LCD does have the ability to display an internal hard drive temperature reading.

In the cooling test, two Hitachi 160GB SATA hard drives were mounted in the SilverSATA II and configured in RAID1 format. The SilverSATA II was mounted on a PowerMac G5 2.0GHz Dual using a Sonnet Tempo-X 4+4 SATA host adapter. For 90 minutes a 4.2GB folder containing two video files was duplicated continuously on the SilverSATA II hard drive. This of course causes the mirror and the master SATA hard drive to continuously write data to the disk. As the SilverSATA II enclosure does not pass temperature data to Hardware Monitor, several temperature probes were attached to the hard drives in the enclosure. In addition, the temperature provided by the SilverSATA II LCD was also monitored. At the end of 90 minutes of continuous hard drive activity the LCD displayed 37 C which equals 99 degrees Fahrenheit. The temperature probes on the hard drives measured 95 degrees Fahrenheit.

Next, the SilverSATA II was allowed to sit idle on the desktop with no sleep for 60 minutes. After 60 minutes of inactivity the temperature was measured again. The SilverSATA II LCD displayed 35 C which is 95 degrees Fahrenheit. The hard drive probes recorded 91 degrees Fahrenheit.

Based on this data, I would expect hard drives mounted in the SilverSATA II for an extended period of time will probably operate between 95 and 99 degrees Fahrenheit. The SilverSATA II provides an excellent cooling environment for SATA hard drives.

Acoustics
The SilverSATA II enclosure has two fans. When they are running they create some wind sounds while keeping the SATA hard drives cool. If the enclosure is five feet away behind the PowerMac G5 Dual 2.0GHz, I can hear the SilverSATA II fans working while the PowerMac G5 is in sleep mode. Once the PowerMac G5 is turned on the SilverSATA II fan noise masks most of the noise made by the PowerMac G5 while in "reduced" energy mode. Once the PowerMac G5 energy setting is moved to "highest" you can hear the PowerMac G5 power supply "chirp" sounds over the SilverSATA II fans. The WiebeTech SilverSATA II has a quiet fan noise but it can easily be heard. The noise is mostly wind sounds.

Sleep
The SilverSATA II enclosure was tested for sleep compatibility with both the Sonnet Tempo-X 4+4 SATA host adapter and a PowerMac G5 USB 2.0 port. Apple Macintosh OS X 10.4.5 was utilized. When the hard drives were dismounted from the PowerMac G5 2.0 Dual before being placed in sleep mode, the PowerMac was able to go to sleep and wake without the SilverSATA II mounted. Disk Utility was able to mount the SilverSATA II after returning from sleep. If the SilverSATA II was left mounted and the Macintosh was placed in sleep mode, the SilverSATA II was ready for use once the computer returned from sleep mode. The SilverSATA II works well with sleep. However, the enclosure fans continue to operate even when the Mac is in sleep mode.

Sleep compatibility with the SilverSATA II enclosure will vary with different SATA host adapters. Some host adapters may not support the SilverSATA II in sleep mode even though USB 2.0 works well. If the firmware of the SATA host adapter does not expect the SilverSATA II enclosure to still be there upon waking from sleep, a disconnect may occur which would require you to re-power the enclosure. If your SATA host adapter does not support sleep with the SilverSATA II, it would be better to dismount and turn off the enclosure before placing the computer in sleep mode.

Energy Usage
According to the Kill-a-Watt electricity usage monitor the SilverSATA II enclosure uses 21 watts of power while idle, when two Hitachi 160GB hard drives are installed in it. When the SilverSATA II is actively copying data 27 watts are utilized. Once you understand that the SilverSATA II can duplicate a SATA hard drive sector by sector, while only using 27 watts without a computer connected, you start to recognize the real power of the SilverSATA II enclosure. Why tie up a PowerMac when you want to create a backup drive? Why not just slide the master into the SilverSATA II and let the backup be created with very minimal power usage? Why not create backups of your server without taxing the computer? The SilverSATA II enclosure can do that too. The low power usage of the SilverSATA II, allows you to clone any SATA hard disk, that can be inserted into the SilverSATA II enclosure, while conserving energy.

Performance
In this test, a PowerMac G5 2.0GHz Dual running Mac OS X 10.4.5 was used with the WiebeTech SilverSATA II enclosure and the Sonnet Tempo-X 4+4 SATA host adapter in slot 2. A two drive Maxtor 300GB RAID1 mirror was created in the SilverSATA II enclosure using its internal hardware RAID capability. DiskTester 1GB read and write tests were performed using a run area test so that this article could display how the 279GB formatted RAID1 performs. DiskTester is a Terminal application that measures the combined performance of a volume and the Mac OS X operating system. Using the command: ./disktester run-area-test --transfer-size 131072 --iterations 3 --test-size 1024 --delta-percent 10 DriveName, puts DiskTester to work testing how the RAID will perform when empty, 10% full 20% full and so on.

SilverSATA II RAID1 SATA DiskTester Run Area Test

Results are shown in MB per second. A Sonnet Tempo-X 4+4 SATA host adapter was used with a PowerMac G5 Dual 2.0 in PCI-X slot 2 with two Maxtor Maxline 300GB model 7V300F0 drives.

The same test was also run with the same exact setup but using RAID0 mode below. In a normal RAID0 test, using a single cable for each drive would provide a write speed of approximately 138MB per second.

SilverSATA II RAID0 SATA DiskTester Run Area Test

Results are shown in MB per second. A Sonnet Tempo-X 4+4 SATA host adapter was used with a PowerMac G5 Dual 2.0 in PCI-X slot 2 with two Maxtor Maxline 300GB model 7V300F0 drives.

As the SilverSATA II only provides about 50% better write performance while in RAID0 mode and lacks the ability to provide a backup mirror copy in that mode, most users will probably want to keep the SilverSATA II configured for RAID1.

For those that may want to use the SilverSATA II with a USB 2.0 port, the same test was also run using the PowerMac G5 2.0 Dual USB 2.0 port. The results are below. As you can see the SilverSATA II enclosure will provide a steady 15.6MB per second write speed and a 17.8MB per second read speed even while the enclosure is 90% full. The USB 2.0 connection is four times slower than when using the SATA port with the SilverSATA II, but it is nice to be able to connect to a USB 2.0 port if you need to.

SilverSATA II RAID1 USB 2.0 DiskTester Run Area Test

Results are shown in MB per second. A PowerMac G5 Dual 2.0 USB 2.0 port was used with two Maxtor Maxline 300GB model 7V300F0 drives.

Discussion
The WiebeTech SilverSATA II enclosure combines the function of a SATA hard disk duplicator with that of an external SATA/USB 2.0 RAID1 enclosure. If you look at what it costs to purchase a stand-a-lone disk duplicator like the Disk Jockey ($329) you begin to see the value built into the SilverSATA II. Those that have no need for the SATA disk cloning features of the SilverSATA II will still find that the hardware RAID1 capabilities of the enclosure are awesome for keeping and creating a duplicate backup of your data. Use of the SilverSATA II enclosure is not limited to SATA connections. While slower, the SilverSATA II USB 2.0 connection provides expanded connection options for iMac, Mac mini, iBook and PowerBook users.

Personally, I see the main feature of the SilverSATA II, being its low energy usage method for duplicating SATA hard drives. However, it provides a wonderful way to increase storage capability and to automatically backup any type of computer data, as many times as you might need. When using the SilverSATA I enclosure with the SilverSATA II you can easily hot swap SATA hard drives between different computers. The SilverSATA II provides any office, lab or home with the ability to easily make fast backups of 3.5" SATA hard drives. This makes backup, hard drive upgrades, and creating identical lab computers for testing or classroom use very simple.

If I were the designer of the SilverSATA II enclosure, the only changes I would make would be to ask the user for verification before automatically backing up the master drive and I would pass SMART temperature values to the computer. I might also offer an IDE version or an insert that would allow the SilverSATA II to work with IDE hard drives too.

Pros
Macintosh OS X, Windows 2K, XP.
Silver aluminum finish.
Activity and power lights.
Mounts up to two external SATA drives.
Hot swap capable.
Backplane design.
Very well constructed.
Only requires one eSATA cable for two drives.
Includes eSATA cable, USB 2.0 cable and RS232 cable.
Supports SATA I and SATA II hard drives.
Can duplicate bootable backup drives.
Great for sector by sector hard drive cloning.
RAID1 automatic cloning capability even without a computer.
Cloned 160GB drive in 65 minutes.
Can be used with RAID 0 (striped) or RAID 1 (mirror).
Performs faster than FireWire 800 when used with SATA.
Supports both SATA and USB 2.0 connections.
No additional driver required.
Optional PC monitoring software included.

Cons
No power switch on front panel. (Only on the rear)
Fan noise is not silent.
Does not pass hard drive temperature data to Hardware Monitor.
Cannot mount two single drives on the desktop.
Uninformed users can easily erase their data.
Hardware RAID0 performance is slower than other solutions.

SilverSATA II gets 4 AMUGs out of 5!
The WiebeTech SilverSATA II provides sector by sector SATA disk duplication functions that usually cost almost as much by themselves. It provides a professional looking station for disk duplication and/or for use as a RAID1 mirror setup that keeps your data backed up. The security of data redundancy that is provided with a Silver SATA II fault tolerant hard drive system is much greater than any single hard drive system. If you are looking for an easy and reliable RAID1 system that can also be used as a SATA disk duplication system, the SilverSATA II is my first choice.

WiebeTech Special Offer - (Requires AMUG Membership)
For a limited time AMUG members can save 10% on the entire WiebeTech line including the SilverSATA series by using the discount code found in the AMUG members only section.

Contact Information:
WiebeTech LLC
8200 E. 34th St. North #1404
Wichita, KS 67226 USA
866.744.8722 Toll Free
http://www.wiebetech.com

Copyright 2006
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