On Thu, Jun 26, 2014 at 5:49 PM, Mark Kirkwood <mark.kirkwood@xxxxxxxxxxxxxxx> wrote: > I have a nice toy to play with: Dell R920 with 60 cores and 1TB ram [1]. > > The context is the current machine in use by the customer is a 32 core one, > and due to growth we are looking at something larger (hence 60 cores). > > Some initial tests show similar pgbench read only performance to what Robert > found here > http://rhaas.blogspot.co.nz/2012/04/did-i-say-32-cores-how-about-64.html > (actually a bit quicker around 400000 tps). > > However doing a mixed read-write workload is getting results the same or > only marginally quicker than the 32 core machine - particularly at higher > number of clients (e.g 200 - 500). I have yet to break out the perf toolset, > but I'm wondering if any folk has compared 32 and 60 (or 64) core read write > pgbench performance? My guess is that the read only test is CPU / memory bandwidth limited, but the mixed test is IO bound. What's your iostat / vmstat / iotop etc look like when you're doing both read only and read/write mixed?
