Hi Matthew,
First - in your existing situation I doubt you are crashing the web server. More likely your graph is taking too long to generate, so the browser simply times out before receiving the reply.
Second - it's already running on multiple threads, so there's no advantage on that front.
There are a couple things you can do;
a) have a look at the graph itself. Why is it taking so long? Probably a factor of keys & filters, but I can't say for sure without an example. I suspect you will need to make an example for us to look at because chances are if you are making a mistake in the View, you're probably not noticing it.
b) if the graph is expected to take a while, because of the amount of data it is scanning, then you can pt a p_web.NoOp() command somewhere inside the graph generation so that the browser "keeps waiting".
Cheers
Bruce