At least my client. I was talking with some people while someone was playing around with a flexible cube, when all of a sudden he did something that made it turn ultra super bright (like shining a full intensitiy white light at close proximity to every portion of the faces of the prim. Happily I see this is overbrightening textures. ^.^) and my client's frame rate dropped from 20 fps to 3 fps. When I said what he did was killing my client he deleted the prim and my frame rate immediately resumed at 20 fps. He said all he did was set the flexi settings as high as they would go.
Pentium 4 2.4 GHz
512 Megs of RAM
ATI Radeon 9700 Pro AGP version