Home
Members Only
Membership
Donations
Reviews
Store
Mail List
Legal


In Association with Amazon.com

May 9, 2008

Compact External eSATA Port Multiplier
A Review of the Addonics 5X1 External eSATA Port Multiplier (AD5ESAPM-E)
By Arthur Whalem

Image courtesy of Addonics Technologies

Addonics is shipping the 5X1 External Port Multiplier (EPM) model AD5ESAPM-E for $95. This device allows up to five direct connect eSATA hard drives to be attached to a single port on a SATA PM compatible host adapter. An external DC 5v power adapter is included to power the device. This small five ounce box measures 1"H x 5.3"W x 2.5"D. The purpose of this article is to determine how the Addonics 5X1 external eSATA port multiplier will perform with an Apple Mac Pro computer.



System Requirements
Works with any OS with a SATA PM compatible controller.
Requires up to five external eSATA hard drives.
Requires eSATA data cables.

What is SATA PM?
A SATA port multiplier also known as "SATA PM" is a device that allows several SATA hard drives to share a single port on a SATA host adapter. Port multipliers typically reside inside an enclosure and are transparent to the hard drives. However, the small Addonics AD5ESAPM-E box provides an external SATA PM solution.



As you can see in the image above, up to five SATA hard drives can connect to the 5X1 external port multiplier. A single eSATA cable attaches the 5X1 PM box to a port on a SATA PM compatible host adapter, which is mounted in a PCI, PCI-X, PCIe or an ExpressCard expansion slot inside the computer. The host adapter has to be PM compatible for this configuration to work. When using a five drive RAID 0 setup, performance can be as high as 220MB/sec. Using SATA PM with "just a bunch of disks" also provides very good performance.

Install
To setup the Addonics 5X1 external PM, simply plug in the power adapter while it is attached to the unit. Now, connect the SATA host adapter to the front of the PM box using an eSATA cable. On the back of the PM, up to five hard drives can be connected using eSATA data cables. When the set-up is complete turn on the hard drives and the power switch on the PM to mount the hard drives on the computer.


When the host adapter is detected the green power and host LEDs will glow on the front of the PM. In addition, when a hard drive is recognized a small green LED will be displayed just to the left of each eSATA port used on the back of the PM. The same LED acts as an activity light and flashes as the hard drives are being accessed.

Host Adapters
The Addonics external 5x1 eSATA port multiplier (AD5ESAPM-E) uses the Silicon Image 3726 PM chip. This chip requires that the SATA host adapter is also port multiplier compatible. Some of the available Apple Mac Pro PCI-Express host adapters that are compatible with the Addonics 5x1 external eSATA port multiplier include the 2-port FirmTek SeriTek/2SE2-E ($99.95) and the 4-port Sonnet Tempo E4P ($299.95), DAT Optic eSATA_PCIe8 ($189) and the Addonics ADSA3GPX8-4EM ($189.99).

 Performance
In this test, a Mac Pro 2.8 GHz running Mac OS X 10.5.2 was used with the FirmTek SeriTek/2eEN4 eSATA 4-bay enclosure and the DAT Optic eSATA_PCIe8 controller in slot 2. The Addonics external 5X1 eSATA port multiplier was used to convert the FirmTek 4-bay into a SATA PM enclosure. Four Samsung 1TB SATA hard drives were installed in the FirmTek 4-bay enclosure and used to create a striped RAID set. DiskTester 10GB read and write tests were performed using a run area test. DiskTester was used to measure the combined performance of the striped RAID set and the Mac OS X operating system. It is a Terminal application which requires the use of Mac OS X Terminal with a command line executable. Using the command: ./disktester run-area-test --chunk-size 128M --test-size 10G --delta-percent 10 DriveName, put DiskTester to work testing how the RAID performs when empty, 10% full, 20% full and so on.



Samsung 4-Drive 3.64TB Striped RAID - DiskTester 10GB Test
SeriTek/2eEN4 & Addonics PM SeriTek/2eEN4 Direct Connect
Area Full write read write read
empty 222 235 380 394
10% 221 231 366 392
20% 220 232 357 416
30% 220 233 388 402
40% 220 235 377 384
50% 220 236 334 364
60% 221 234 343 346
70% 220 234 307 329
80% 221 234 284 299
90% 221 235 260 261
100% 213 216 215 215
Average 220 232 328 346
Results are shown in MB per second.

As shown in the chart above, the direct connect enclosure can provide higher performance but is limited to using four hard drives. The Addonics external PM configuration only requires a single eSATA port. As a result, while direct connect is faster (with the same number of hard drives) a PM configuration can support up to 5x more hard drives. If two PM boxes were used with eight hard drives, the performance should be higher than the four drive configuration and will provide additional disk space.

The advantage of a port multiplier is that users can connect multiple SATA hard drives to a single port on a host adapter. This provides the option to expand the number of hard disks connected to the computer. While SATA PM provides fast FIS (Frame Information Structure) based switching between hard drives attached to the Addonics external 5X1 SATA PM, it will usually perform a little slower than a direct connect configuration.


The Addonics 5X1 eSATA external port multiplier is the second external port multiplier that AMUG has reviewed. The first unit was from DAT Optic. An external port multiplier can be used as a SATA hub when a PM compatible card is available. This could be with a Mac Pro, PowerMac G5 or an ExpressCard like the FirmTek/2SM2-E with the Apple MacBook Pro. If occasionally the user wants to connect multiple eSATA hard drives to a single PM compatible port this solution will do it. In addition, the Addonics 5X1 eSATA external port multiplier can be used to convert existing direct connect enclosures (like the FirmTek 4-bay enclosure used in the performance tests) into a PM enclosure.

There are a few draw backs to using an external PM. This setup usually provides a messy data cable look while a 5PM enclosure looks great and only requires a single cable. Less external cables, also means less chances for accidental cable disconnection. If I wanted a permanent PM configuration I would purchase a 5-bay PM enclosure rather than use an external PM.

However, if you need a mobile eSATA hub and only connect a few hard drives occasionally the Addonics 5X1 eSATA external port multiplier may be just what you are looking for. In addition, users that want the ability to convert an external direct connect enclosure to support a port multiplier configuration can easily do so with this eSATA PM hub. Removing the hub allows the enclosure to instantly revert back to direct connect.

Pros
Works with up to five eSATA direct connect HDs.
Allows a single host adapter port to mount up to five hard drives.
Works with SATA I and SATA II hard drives.
Provides power, host and drive activity lights.
Supports hot swap and sleep.
Utilizes FIS-based switching.
Great JBOD performance.
Works with RAID1 or RAID0 Disk Utility created RAID sets.
Can be used as an eSATA Hub.
Easy to use, small footprint, quiet operation.

Cons
Requires a power adapter.
Requires a SATA PM controller.
SATA PM can be slower than direct connect with a striped RAID set.


Addonics 5X1 Ext. Port Multiplier gets 4 AMUGs out of 5!
Users that already have direct connect eSATA enclosures and would like to use them occasionally with SATA PM connections, will find the AD5ESAPM-E can provide this feature. In addition, mobile MacBook Pro users wanting to connect more than one hard drive to an eSATA ExpressCard data port may want to add the Addonics PM hub to their bag of accessories.

Contact Information:
Addonics Technologies
2466 Kruse Drive,
San Jose, CA 95131 USA
408-433-3899
addonics@addonics.com
http://www.addonics.com

Copyright 2008
Arizona Macintosh Users Group, Inc. (AMUG). Visit AMUG at www.amug.org for news, discounts and friends. JOIN AMUG!