Why does using the G15 add-on cause a massive FPS drop?

[Rossa_AU]

I know this is an old game that isn't very popular, so i wont expect a response (at least any time soon anyway); but i was just wondering why using the G15 keyboard add-on causes massive FPS drops in this game. It's not something i care about by any means, i can deal without it; but it's got me curious as to why something like that can effect the game so much?

For example, on the highest graphics and at native res i get:
- 8 FPS in the menu and 10-15 FPS in game, that's with the add-on turned on.
- With it turned off, i get 68 FPS in the menu and 45-50 in game.

Can anyone shed some light on this pointless question i have? haha

[mesaone]

I have the same problem, but I can't seem to fix it.

I disable the applet in Logitech Gaming Software, but still I get low FPS when I shouldnt.

EDIT: restarting my computer with my G510 disconnected, I get more than 120 FPS in this game. How do I disable the applet and still use my keyboard?

[Phoenix9000]

I ran across this in a search:

http://forums.steampowered.com/forum....php?t=1288020

Found this too:

http://forums.steampowered.com/forum....php?t=1279444

I know this is for the F.E.A.R. series, but it's the same hardware in question so a similar fix might have the same results. Hope that helps!

Edit: Oh, and it may not be a very popular game but I like it a lot so I'll help in any way I can. Legendary got bad ratings that it didn't deserve. I still have fun playing it.