
The ARS-3031 may look like another 1U rackmount server, but what Taiwan-based storage vendor Acard has designed is a storage appliance. Indeed, as a highly-specialized computer system, the ARS-3031 serves basic storage needs and offers RAID capabilities. The whole box can be attached to servers or workstations with an ultraSCSI connection, with 2 TB of storage capacity.
The storage device's components comprise a solid 1U 19" rackmount case, a hardware RAID controller that supports four SATA hard drives and an UltraSCSI bridge solution for SCSI infrastructure connections. To facilitate maintenance tasks, the hard drives are inserted with aluminum frames that are easy to remove. Finally, the system offers a DDR DIMM socket in order to plug in a memory module of your choice, which can be used as cache memory for the RAID controller.
So, is the SATA-to-UltraSCSI solution fast enough or does it generate performance bottlenecks? To find out, we compared the ARS-3031 to Areca's ARC-1220 PCIe SATA II RAID controller, which represents a RAID solution that would offer a good fit for the storage needs of an existing server.

The ARS-3031 is configured with DIP switches on the back of the unit, which are used to select one of the following RAID operation modes: JBOD (just a bunch of drives), RAID 0 (striping), RAID 1 (mirroring), RAID 0+1 (mirroring + striping), RAID 3 (striping with parity) and RAID 5 (striping with rotating parity). You can also specify a hot spare hard drive to rebuild the array if a drive should fail.
During the configuration process, the DIP switches first need to be disabled at the same time. This causes a system reset of the ARS-3031, which is confirmed by three beeps. You can then select the dip switch configuration that will set your preferred RAID mode. The SCSI ID is set using the same dip switch block. An automatic SCSI ID assignment via SCAM, however, did not work during our test.
If there is a problem with the RAID array (which would usually be a broken drive), the ARS-3031 lets you know with a built in alarm. Luckily there is a mute button on the front of the appliance. We recommend attaching the lockable front grid in order to make the drives and the mute button inaccessible, so an alarm will not be accidentally set off.
The SCSI interface uses 68-pin low-voltage differential SCSI cable. Though Acard provides one, its length of approximately 20" is inadequate, because it reduces your operating range and forces you to deploy the ARS-3031 right above or below your host system - unless you go ahead and buy a larger cable, which again can be expensive.
The noise level of 60 db(A) that we measured at a distance of approximately one yard from the device makes the appliance far too noisy for an office environment. Unfortunately, the fans always rotate at their maximum speed, which causes considerable noise and reduces this device's flexibility. Temperature controlled fans would not change the system cost dramatically and would make it possible to run it outside of server rooms if necessary.
We simulated a failed drive by removing one of the array components. As expected, the test array (RAID 5) remained operational. Reinserting the drive triggered an automatic array reconstruction process.



It's nice to see that Acard provides a SCSI terminator to end the SCSI link correctly. Terminators are used to avoid signal reflection.

The ARS-3031 was designed systematically and hosts four 3.5" SATA hard drives in the front part of the system. All of these are installed using aluminum frames. However, their locking mechanisms do not protect the drives from being removed accidentally (see image above), so you should mount the front cover whenever you do not need to access the drives. The front part of the appliance will also host a battery of LEDs that show drive status and activity.


Acard designed one of its own Ultra160 SCSI RAID controllers (see image above). As Ultra320 SCSI is downwards compatible, any Ultra160 device can be placed into the SCSI chain.
Setting up the ARS-3031 in RAID 0 mode with four hard drives makes it easy to exceed the Ultra160 SCSI's available bandwidth (usually < 130 MB/s). However, you won't find these bandwidths very often, since only few application scenarios powered by an insecure RAID 0 array make sense. We expect RAID 0+1 or RAID 5 to be the predominant choices. In this case, the Ultra160 bandwidth will be enough.


Acard offers software that is simply called RAID Monitor. There is a server part that needs to be installed on the host system, but this part does not really reveal a lot. The client part has to be installed on any computer that has network access to the host system running Acard's ARS-3031. However, the application requires the Java 2 Runtime Edition and still does not do more than show drive status and the event log. It is not capable of generating warning signals in case of problems.


| System Hardware | |
|---|---|
| Processor(s) | 2x Intel Xeon Processor (Nocona core)
3.6 GHz, FSB800, 1 MB L2 Cache |
| Platform | Asus NCL-DS (Socket 604)
Intel E7520 Chipset, BIOS 1005 |
| RAM | Corsair CM72DD512AR-400 (DDR2-400 ECC, reg.)
2x 512 MB, CL3-3-3-10 Timings |
| System Hard Drive | Western Digital Caviar WD1200JB
120 GB, 7,200 UPM, 8 MB Cache, UltraATA/100 |
| Mass Storage Controller(s) | Intel 82801EB UltraATA/100 Controller (ICH5)
Adaptec AIC-7902 Ultra320 |
| Networking | Broadcom BCM5721 On-Board Gigabit Ethernet NIC |
| Graphics Card | On-Board Graphics
ATI RageXL, 8 MB |
| Benchmarks | |
| I/O Performance | IOMeter 2003.05.10
Fileserver-Benchmark Webserver-Benchmark Database-Benchmark Workstation-Benchmark |
| System Software & Drivers | |
| OS | Microsoft Windows Server 2003 Enterprise Edition, Service Pack 1 |
| Platform Driver | Intel Chipset Installation Utility 7.0.0.1025 |
| Graphics Driver | Default Windows Graphics Driver |
We used four Seagate Barracuda 7200.9 400 GB hard drives to test the Acard ARS-3031.





Acard's ARS-3031 made a good impression, especially when you consider the device is in the sub-$1,000 price range. The hard drive frames are solid, and even inexperienced users can configure the system. Thanks to an external Ultra160 SCSI interface, the ARS-3031 can be hooked up to virtually any server or workstation host system using LVD cabling. Several of these appliances can also be SCSI-daisy-chained, which is not possible with eSATA appliances.
We found the RAID monitor software to be more of a cosmetic add-on, because it does not provide any real value that exceeds very basic drive monitoring. There is an event log to track status changes, but the system won't notify you by email in case one of the drives should fail.
The benchmark results are not close enough to what we expected prior to the testing. The IO benchmark graphs are flat rather than rising as the command queue depth increases, which indicates a bottleneck - whether this originated in the RAID controller's cache or was caused by the UltraSCSI-to-SATA bridge. As a result, the ARS-3031 delivers only 50% of the performance level that can be achieved by installing a current SATA RAID controller and four drives into existing server systems.
We do not recommend this product for application scenarios that require high storage performance due to its somewhat disappointing benchmark results. However, flexibility often is more important than performance, which is why we can still recommend the Areca appliance. Many rackmount servers cannot be upgraded by installing hard drives due to space constraints. As a result, the ARS-3031 can be called a viable solution for upgrading storage to existing SCSI infrastructures.