Performance in WinBench 99
We use WinBench 99 to record data-transfer graphs:
Data-transfer graphs of RAID arrays on the Promise SuperTrak EX8650 controller:
- RAID0, 4 disks
- RAID0, 8 disks
- RAID10, 4 disks
- RAID10, 8 disks
- RAID5, 4 disks
- RAID5, 8 disks
- RAID6, 4 disks
- RAID6, 8 disks
We’ll compare the data-transfer rates at the beginning and end of the virtual disks:
The read speeds agree with the theory except that the eight-disk arrays are not much different from the four-disk RAID0.
Summing everything up, the Promise SuperTrak EX8650 is a good controller, but you shouldn’t use it without a battery backup unit unless you don’t care a bit about the speed of writing to your arrays. To be specific, this controller delivers good performance under server loads, can read fast from mirror arrays, and has a good implementation of RAID5 and RAID6.
Unfortunately, it is not free from drawbacks. For example, we were disappointed at poor scalability of arrays built out of many disks. The controller works better when there is a large amount of requests in the queue and has low speed with real files as the result. It also lowers its write speed inexplicably at some combinations of array type and the amount of disks. So, people from Promise have a lot of work to do yet on this model.
As for the missing BBU, we are going to retest the SuperTrak EX8650 with the battery as soon as we get one.