Yes there is a particles counter, and it freeze @22k (for water)

Default water particles is 20k, you can raise it to 22k, after that value, nothing happen, BUT if you have multiple emitter, you can obtain more than 22k of water particles, i reach 54k, and not tried over.

how do you activate the particle counter?

http://img35.imageshack.us/img35/6139/cryow.jpg

As you can see the system can handle nearly 60.000 particles, @60 FPS, from 20k to 60k the drop is just 8~9 FPS, so particles number can be increased A LOT, anyway, the command is

d.showstats 8

There lot of parameter available... from 1 to 20, each parameter show different debug information, this is really usefull, with that i succesfully implemented a very 'primitive' blood mod.

wow, that is a nice discovery! congratulations. somehow i must have overlooked this option. i always had a feeling that more particles would be possible, although 60.000 seems to be quite a number. fluidmark only benchmarks graphics cards with 30.000 particles. still, i'd like to see the particle count pushed past the 100.000 mark. what graphics card are you running the game on?

Here my system spec
http://valid.canardpc.com/show_oc.php?id=451679

The GPU is an overclocked (not too much) GTX 280

edit:

http://www.youtube.com/watch?v=cLzZr37bKrU