How Fast and Robust Is Your Storage? - Professional SQL Server 2005 Performance Tuning - page 444

Table 12-6: Single-Disk Test Results (continued)

Read/Write Sequential/Random Block Size IOPS MB/Sec Avg Latency

R sequential 16 3,767.30 58.86 0

R sequential 32 1,892.50 59.14 0

R sequential 64 948.30 59.26 0

R sequential 128 474.10 59.26 1

R sequential 256 237.00 59.25 3

R sequential 512 118.60 59.30 7

R sequential 1,024 59.30 59.30 16

R sequential 2,048 29.65 59.31 32

R sequential 4,096 14.83 59.32 66

R sequential 8,192 7.34 58.74 135

W sequential 8 6,958.20 54.36 0

W sequential 16 3,765.30 58.83 0

W sequential 32 1,884.40 58.88 0

W sequential 64 947.40 59.21 0

W sequential 128 470.40 58.80 1

W sequential 256 236.40 59.10 3

W sequential 512 118.00 59.00 7

W sequential 1,024 59.00 59.00 16

W sequential 2,048 29.55 59.10 33

W sequential 4,096 14.75 59.01 67

W sequential 8,192 7.38 59.11 134

Now let's see what you can determine as the I/O characteristics of this single disk.

To start off with, you want to know what is the max throughput you can possibly get from this disk at
an acceptable latency (max of 10mSec). That's a fairly easy one; you need to find the highest MB/Sec
figure (and the corresponding IOPS) where latency is < 10 msec. From just looking through the data, you