pgbench results

[Mark Kirkwood]

Ivan Voras wrote:
>
> The thing is - I *do* have a similar setup here: HP DL370 G5, 2x4-core
> 1.86 GHz, 4 GB RAM, 6 drives in RAID10, 512 MB cache (can pull > 200
> MB/s off the array), with all settings like in the posted link except
> shared_buffer=1900 MB, and I "only" get this:
>
> tps = 2834.026175 (including connections establishing)
> tps = 2839.080739 (excluding connections establishing)
>
> This is still far bellow ~~ 4500 trans/s from the link and I wonder if
> my results are within what I should be getting. The benchmark in the
> link above was done with faster CPUs (but I'm not CPU bound - at least
> 30% idle), but with 3 times the memory and I'm guessing more memory
> would help here, but I'm not sure.
>
> What's strange is that toggling synchronous_commit doesn't have a
> significant effect on performance (it does increase CPU idle time). With
> synchronous_commit=off, I get:
>
> tps = 2886.980477 (including connections establishing)
> tps = 2891.776081 (excluding connections establishing)
>
>   

The article refers to a controller with a battery backed write cache - 
that could easily explain the difference if you do not have one (he's 
paying nothing for fsync wheres you are).

regards

Mark