Run #2: /usr/bin/tiotest -t 256 -f 8 -r 15 -b 4096 -d . -T    

File size in megabytes, Blk Size in bytes. 
Read, write, and seek rates in MB/sec. 
Latency in milliseconds.
Percent of requests that took longer than 2 and 10 seconds.

Sequential Reads
                              File  Blk   Num                    Avg       Maximum     Lat%     Lat%    CPU
Kernel                        Size  Size  Thr   Rate  (CPU%)   Latency     Latency      >2s     >10s    Eff
---------------------------- ------ ----- ---  ------------------------------------------------------------
2.4.19-pre4-ac3-preempt       2048  4096  256    9.46 5.271%   181.668    30992.77   3.60280  0.05836   179

Random Reads
                              File  Blk   Num                    Avg       Maximum     Lat%     Lat%    CPU
Kernel                        Size  Size  Thr   Rate  (CPU%)   Latency     Latency      >2s     >10s    Eff
---------------------------- ------ ----- ---  ------------------------------------------------------------
2.4.19-pre4-ac3-preempt       2048  4096  256    0.67 0.980%  2446.793    14462.86  39.66145  0.00000    68

Sequential Writes
                              File  Blk   Num                    Avg       Maximum     Lat%     Lat%    CPU
Kernel                        Size  Size  Thr   Rate  (CPU%)   Latency     Latency      >2s     >10s    Eff
---------------------------- ------ ----- ---  ------------------------------------------------------------
2.4.19-pre4-ac3-preempt       2048  4096  256    5.36 5.029%   160.584   209853.98   0.42915  0.37536   107

Random Writes
                              File  Blk   Num                    Avg       Maximum     Lat%     Lat%    CPU
Kernel                        Size  Size  Thr   Rate  (CPU%)   Latency     Latency      >2s     >10s    Eff
---------------------------- ------ ----- ---  ------------------------------------------------------------
2.4.19-pre4-ac3-preempt       2048  4096  256    0.67 0.533%     0.047        4.50   0.00000  0.00000   125