[Disksim-users] Write throughput

[Youngjae Kim]

Dear all,

I tested write/read throughput with Barracuda disk (barracuda.diskspecs, 
barracuda.parv) for synthetic workloads. The configuration for my test and 
results are as follows.

1. Config.

I varied sequentiality (0-1). Inter-arrival time is set to be very small 
enough to fill up the queue all the time. The request size is 8 blocks 
(8*512=4KB). I tested every case till the program is aborted because of 
queue filled up.

2. Results

Regardless of sequentiality, write throughputs are almost the same. I don't 
know why this happens. IOPS is around 100. However, the read throughput 
varies according to the sequentiality, from 100 to 200.

Do you have any idea of why write throughput is smaller than read throughput 
and why write throughput does not change with the sequentiality of the 
workloads? And in the implementation, is there any additional overhead to 
the writes different from read ones?

Thank you.
YJ,