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RAID 0 Testing
Now for my favorite part of hard drive
testing; RAID!!! Yes, our friends over at
Seagate sent over a
pair of the Cheetah 15K.6 hard drives for our testing pleasure. And
trust me, this is the most fun I've ever had benchmarking hard drives!
Using the onboard SAS RAID controller, we
combined the hard drives using 64Kb stripe size. Running multiple hard
drives dramatically increases the overall data transfer performance as
you will soon see.
Striping (RAID 0)
When a disk array is striped, the read and
write blocks of data are interleaved between the sectors of multiple
drives (see Figure 11). Performance is increased, since the workload is
balanced between drives (or "members") that form the array. Identical
drives are recommended for performance as well as data storage
efficiency.
The disk array’s data capacity is equal to the number
of drive members multiplied by the smallest array member’s capacity. For
example, one 100 GB and three 120 GB drives will form a 400 GB (4 x 100
GB) disk array instead of 460 GB. The stripe block size value can be set
logically at 8KB, 16KB, 32KB, 64KB, and 128KB. This selection will directly affect
performance. Larger block sizes are better for random disk access (like
email, POS, or web servers), while smaller sizes are better for
sequential access.

2x Hard Drive Test (RAID 0)
Hard Drive Tach - 8MB Zones

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Burst Speed: |
2235.2 MB/s |
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Average Read: |
178.5 MB/s |
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Average Write: |
567.9 MB/s |
Isn't this the craziest hard
drive benchmark you have ever seen? 2.2GB/s burst speed??? Can that
be correct? I ran the 8MB Zone benchmark about a dozen times and
each benchmark showed nearly identical results. The write speed is
just crazy. The write speed bottoms out at around 90 MB/s and then
blows the roof hitting over 1200 MB/s. I'm a little skeptical on
these results and we are waiting for a confirmation back from
Seagate. So until this, I can only assume these numbers are
accurate.
2x Hard Drive Test (RAID 0)
Hard Drive Tach - 32MB Zones
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Burst Speed: |
2256.7 MB/s |
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Average Read: |
178.7 MB/s |
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Average Write: |
160.2 MB/s |
At 32MB Zones, the write speed
benchmark smoothes out to something more believable, but the burst
speed is still over 2.2 gigabytes per second. If these results are truly
correct, this is the most amazing hard drive benchmark I have ever
achieved on a desktop computer.
2x Hard Drive Test (RAID 0)
HD
Tune: Read Only
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Minimum Transfer Rate: |
143.7 MB/s |
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Maximum Transfer Rate: |
191.0 MB/s |
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Average Transfer Rate: |
169.1 MB/s |
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Access Time: |
5.6 ms |
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Burst Rate: |
88.7 MB/s |
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CPU Usage: |
6.3% |
Switching back to HD Tune we see some very
impressive numbers, but nothing like HD Tach's 8MB Zone bench. Even the
burst rate is down. In fact the burst rate is slightly less than a
single Cheetah 15K.6. Mixed results, not what I like to see. Regardless,
the overall scores are extremely impressive.
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