We have 2 load balanced K2 host servers running smartforms (and blackpearl) with the SQL server on a separate server (also running SharePoint 2010). Our experience so far has been that if no form has been requested (opened in a browser) for some time (e.g. overnight) then then the first form will take a long time (10-15 seconds) to render. If the same form is requested again soon after (by any user) it will render in the expected time (1-2 seconds). It also appears that any other form requested will then render quickly as well.

Do smartforms get cached - either locally, or on the K2 or database server? It seems to me from the behaviour we see there could be some sort of server caching going on - but that does not completely explain the behaviour we see as other forms render quickly after the first. Or it could be that the "K2 Forms Service" needs warming up if not active for a period?

Is there any way to "warm up" forms or the K2 forms service to prevent the first user from experiencing this poor performance?

I understand there are ways to improve a forms loading performance and some of these we have implemented, but as I mentioned above the form does render in the expected time after it has been requested for the first time.