Now let’s compare the performance of RAID 1 array and JBOD, and RAID 01 array and RAID 0 array of two drives.
As you see, RAID 1 array is just as fast as a single HDD during writes, while RAID 01 array yields just a little bit to RAID 0 of two drives when processing 8KB and 16KB blocks.
The tests in SequentialRead and SequentialWrite patterns showed that WB-caching algorithms implemented in TX4000 controller differ a lot from those we discussed in our Dual-Channel SerialATA RAID Controllers Roundup.
Intel IOMeter: WorkStation
Now comes the WorkStation pattern. It should imitate intensive work in different applications in NTFS5 file system.
In order to compare the performance of different RAID array types and to try evaluating the efficiency of WB-caching, we will make up a diagram with the array performance ratings. These ratings are calculated according to the following formula:
Performance = Total I/O (queue=1)/1 + Total I/O (queue=2)/2 + Total I/O (queue=4)/4 + Total I/O (queue=8)/8 + Total I/O (queue=16)/16 + Total I/O (queue=32)/32
As you see, RAID 0 arrays of three and four hard drives again proved to be the fastest, which actually correlates with WinBench results. However, unlike WinBench, RAID 01 array appeared to be far ahead RAID 0 array of two drives and is almost pushing at the back of RAID 0 array of three drives! Besides, RAID 1 array also managed to get somewhat ahead of the single HDD, although unfortunately, it didn’t defeat the dual-drive RAID 0.
Note that WB-caching appeared quite beneficial for almost all array types (because the WorkStation pattern contains a big sharer of write requests).