Testbed and Methods
The following benchmarks were used:
- IOMeter 2003.02.15
- WinBench 99 2.0
- FC-Test 1.0
- Intel SC5200 system case
- SuperMicro X6DHT-G mainboard
- Two Intel Xeon 2.8GHz CPUs
- 2 x 512MB PC3200 ECC Registered DDR SDRAM
- IBM DTLA 307015 hard disk drive as system disk (15GB)
- Onboard ATI Rage XL graphics controller
- Windows 2000 Professional with Service Pack 4
We used the latest BIOS and drivers for the controller and installed it into the mainboard’s PCI Express x8 slot.
The Fujitsu MBA3073RC hard disks were installed into the standard boxes of the SC5200 system case. The controller was tested with four and eight HDDs in the following modes:
Thus we wanted to cover all possible arrays types, yet not overcrowd the review with redundant data. The test time and the amount of diagrams would be enormous if we tested the same types of arrays built out of a different number of disks. So, we had tried to find a compromise and hopefully we succeeded.
For comparison’s sake, we publish the results of a single Fujitsu MBA3073RC hard disk as a kind of a reference point.
The controller was set at the Performance mode for maximum performance during the tests. This mode allows deferred writing and look-ahead reading for both the controller (in its own buffer memory) and the disks. Unfortunately, there was a problem we couldn’t avoid as the controller came to us in its basic kit, i.e. without a battery backup unit. Although the controller allows to check the Write Back checkbox in its settings to enable deferred writing, it refuses to perform such writing if there is no battery, reporting this honestly in the log files after each server reboot. As a result, deferred writing is performed by means of the cache memory of the HDDs, without the controller’s cache. The outcome of this will be shown below.
It is easy to see that deferred writing is indeed turned off. You can just take a look at the diagram of reading from the drive’s cache recorded in IOMark. We don’t use this program with RAID arrays, but it came in handy this time around (we checked out an eight-disk RAID0):
The controller’s performance with disabled caching may be interesting for people who use advanced UPSes, confide in their equipment and don’t want to buy the battery. Yet we have some gripes that the controller’s kit does not include a battery by default and that the status of deferred writing in the controller’s cache is not shown in an obvious way.