System setup, notes and issues
We tested the TwoBig using some methods devices after our Thecus N2050 review, so while we can't directly compare results, we'll drop in a mention of the N2050's performance where appropriate. In our test results we've included figures from a handful of internal SATA devices that we've benchmarked. SATA or eSATA performance should be about the same (with like for like hardware), which is one of the great benefits the interface has over USB, which is of course considerably slower than IDE.
Below is the specification of the test system to which the 1TB Two Big was attached:
| Component | Details |
|---|---|
| Processor | AMD Athlon FX-55 Socket 939 |
| Motherboard | ASUS A8N SLI Deluxe - BIOS 1017-004 |
| Memory | 2x 512MiB Corsair ValueSelect PC3200 |
| Graphics | Radeon X1600 256MiB |
| Hard drive | Maxtor 250GB 3Gbps SATA |
| Operating System | Windows XP Professional 32-bit SP2 |
| SATA cards | Silicon Image 3124 PCI-X running as PCIc Silicon Image 3132 PCIe x1 |
The storage devices we're going to compare the Two Big to were tested on a slightly different testbed arrangement, but the storage performance shouldn't be affected enough to misrepresent the TwoBig. In any case, we're not graphing anything intended to compete with the Two Big, the numbers are simply there to show how well it is doing.
The disk configurations we compared the Two Big against are:
- 4x 750GB Seagate SATA 3Gbps attached to LSI MegaRAID in RAID-5
- 2x Seagate 250GB SATA 3Gbps attached to NVIDIA nForce 4 SATA in RAID-0
- Single ST3750640AS 750GB SATA 3Gbps drive
We ran RAID-0 and RAID-1 benchmarks on the Two Big device, using both PCIe and PCI-X cards.
Testing software
IOMeter 2004.07.30
IOZone 3.263
HD Tach RW 3.0.1.0
For IOZone, we ran our usual read/write tests, taking the file size up to 1GB, with record sizes up to 16MB on a single, NTFS formatted-partition.
HD Tach was run on unformatted disks, allowing us to undertake write tests to verify our other write-test results. However, we'll only be graphing burst results.
Finally, here's our testing regime for IOZone, also applied to unformatted disks:
| Option/Test | Configuration |
|---|---|
| Outstanding I/Os | 10 |
| Individual test run time | 30 seconds |
| Read test access spec | 1MB transfers 100% sequential 100% read |
| Write test access spec | 1MB transfers 100% sequential 100% write |
| General usage access spec | 64KB transfers 50% sequential, 50% random 33% write, 67% read |
Notes and issues
When configuring the disks of the Two Big, two are presented (when in RAID mode, at least). One is the array, while the other is a configuration disk that's only a few MB in capacity. Quite why the configuration disk is visible to the OS is unknown, for it cannot be initialised by disk management. Don't try to benchmark it either... we found it didn't like that.
Two Big supports RAID-0, RAID-1, JBOD and concatenation. RAID-0 and RAID-1 are the two most useful modes, providing either speed or security, so we tested with them. To set a RAID mode, a switch on the back must be turned and then, for 10 seconds as the device turns on, a button held in with something pointed. This makes changing RAID mode impossible to do by accident, which is a good safeguard.
Hot plug 'n' play of the TwoBig worked fine. Changes to RAID configuration and partitions could be done without the need for a restart. We'd want nothing less from SATA.
We took a drive offline while in RAID-1 mode and the device still operated fine. Reinserting the 'broken' drive brought it back online and the mirror started to rebuild itself. The rebuild process appears to take three to four hours, from our observations.
