The option is fully titled: "Write to disk at most every xxx seconds". Nothing about a maximum interval, it's the smallest *allowed* interval what's controlled. Could not be maximum as the sciences are in control of generating checkpoints, which the client settings can either deny [skip] or permit... for instance for sciences checkpoint every 30 seconds. Default "at most" is 60 seconds. The more cores in a system, the larger the interval setting is recommended. Mine on an Octo is 600 seconds, so *at most* there's an average of 1 checkpoint on the system per 1.125 minutes (if the science is ready to checkpoint).

For further discussion on why these large intervals on CEP2 (models in memory reach Gigabyte sizes), you're referred to prior threads in this forum.

--//--