I/O throughput analysis

[Jamon Camisso]

On 1/22/2011 2:28 PM, William Muriithi wrote:
> Hello pals,
>
> A workmate and I had an argument that we could not seem to agree on
> yesterday. That mean we did not learn anything from the discussion and
> I would like to hear your opinion on it. It could help make sense of
> each other arguments
>
> Which of these two systems would have a better input output
> performance?  Both system have the same configurations, CPU, chipset
> everything down the power supply. They differ though with the number
> of hard disk.  Both system has a RAID card with a maximum speed of 6
> GB per sec
>
> System A  has 6 drives. Each drive has a specification of 1500 RPM,
> 300 GB size SAS interface.
>
> System B has 8 drives.  Each drive is 146GB in size, 1500 RPM and also
> with a SAS interface.
>
> SAS interface can comfortably handle 3 GB per second.
>
> So, in your opinion, is the RAID card a potential bottleneck on both systems?
>
> Which of the two system would offer a better throughput ?

If you're after bottlenecks, you haven't told us about your PCIe slots.
Do you have 2.0 slots? x8 or x16 slots will be needed to reach your 
controller's maximum of 6gbps. If 1.0 then you'll have to solely use x16 
slots to have enough bandwidth.

If your PCIe slots aren't up to the task, then no amount of drives in 
any configuration will really achieve the performance you're looking to 
benchmark.

Jamon
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