Boost On Demand RRD Update doesn't change poller runtime

[jimj]

I originally asked about this here: http://forums.cacti.net/viewtopic.php?p=168325#168325 but it's really a different topic so I'm starting a new thread.

Stats:
CactiEZ v0.6:
Cacti v0.8.7c
Boost 2.4
155 hosts
896 data sources
461 RRDs
Boost Update Frequency: 30 Minutes
Maximum Records: 100000 Records
Average poller runtime: 28 seconds
Hardware = VMware virtual machine (unsure of underlying hardware specs)


When I enable boost my poller runtime doesn't change. Whether or not boost is enabled my poller runtime averages about 28 seconds. I've read nothing but good things about boost cutting poller runtimes down by a factor of 10. How could my runtime stay exactly the same?

AFAIK boost is configured and working correctly. I've confirmed My RRD files are only updated every 30 minutes (unless I'm viewing the corresponding graph(s) of course).

My (probably incorrect) basic understanding of the boost "On Demand RRD Update" feature is that it decreases your poller runtime by eliminating disk IO since it saves all the RRD updates in RAM. Then every 30 minutes (in my case) it does a bulk update of the RRD files. I.e. boost separates the polling and RRD updating functions. So could it be if your server isn't IO bound boost could yield no improvement even if it's configured correctly?