Increased the test file size to 150GB and performed another round of tests ...

64KB random IOs

sqlio v1.5.SG

using system counter for latency timings, 2474091 counts per second

parameter file used: data_param.txt

file E:\SQL_Data\MSSQL\testfile.dat with 2 threads (0-1) using mask 0x0 (0)

2 threads writing for 120 secs to file E:\SQL_Data\MSSQL\testfile.dat

using 64KB random IOs

enabling multiple I/Os per thread with 8 outstanding

buffering set to use hardware disk cache (but not file cache)

using specified size: 150480 MB for file: E:\SQL_Data\MSSQL\testfile.dat

initialization done

CUMULATIVE DATA:

throughput metrics:

IOs/sec: 677.04

MBs/sec: 42.31

latency metrics:

Min_Latency(ms): 1

Avg_Latency(ms): 23

Max_Latency(ms): 660

histogram:

ms: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24+

%: 0 1 2 4 8 9 9 11 12 11 8 7 4 3 1 1 1 1 0 0 0 0 0 0 7

64KB sequential IOs

sqlio v1.5.SG

using system counter for latency timings, 2474091 counts per second

parameter file used: data_param.txt

file E:\SQL_Data\MSSQL\testfile.dat with 2 threads (0-1) using mask 0x0 (0)

2 threads writing for 120 secs to file E:\SQL_Data\MSSQL\testfile.dat

using 64KB sequential IOs

enabling multiple I/Os per thread with 8 outstanding

buffering set to use hardware disk cache (but not file cache)

using specified size: 150480 MB for file: E:\SQL_Data\MSSQL\testfile.dat

initialization done

CUMULATIVE DATA:

throughput metrics:

IOs/sec: 700.92

MBs/sec: 43.80

latency metrics:

Min_Latency(ms): 1

Avg_Latency(ms): 22

Max_Latency(ms): 665

histogram:

ms: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24+

%: 0 1 2 4 7 8 10 11 12 11 9 7 4 2 1 1 1 1 0 0 0 0 0 0 6

64KB random IOs (reads)

sqlio v1.5.SG

using system counter for latency timings, 2474091 counts per second

parameter file used: data_param.txt

file E:\SQL_Data\MSSQL\testfile.dat with 2 threads (0-1) using mask 0x0 (0)

2 threads reading for 120 secs from file E:\SQL_Data\MSSQL\testfile.dat

using 64KB random IOs

enabling multiple I/Os per thread with 8 outstanding

buffering set to use hardware disk cache (but not file cache)

using specified size: 150480 MB for file: E:\SQL_Data\MSSQL\testfile.dat

initialization done

CUMULATIVE DATA:

throughput metrics:

IOs/sec: 1794.08

MBs/sec: 112.13

latency metrics:

Min_Latency(ms): 0

Avg_Latency(ms): 8

Max_Latency(ms): 80

histogram:

ms: 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24+

%: 0 0 0 0 7 1 1 1 86 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1

Wonder why I can't get anything lower or equal tha 20ms on random writes... or, what should I tweak to get better latency values.

I do like the read and random IO results though, 8ms average. Giving the case of the file's size, 150GB, I do not believe is being cached by the SAN disk controller ...

Any opinions?