Post
by horo » Tue Apr 28, 2009 3:20 pm
Hi,
did some "research":
linux:
bmAttributes=2 (bulk), bIntervall don't care -> 2ms poll, low cpu load
bmAttributes=3 (interrupt), bIntervall=1..3 -> 2ms poll, low cpu load
bmAttributes=3 (interrupt), bIntervall=4..7 -> 4ms poll, low cpu load
bmAttributes=3 (interrupt), bIntervall=8..15 -> 8ms poll, low cpu load
bmAttributes=3 (interrupt), bIntervall=16..31 -> 16ms poll, low cpu load
bmAttributes=3 (interrupt), bIntervall=0 or 32..63 -> 32ms poll, low cpu load
bmAttributes=3 (interrupt), bIntervall=64..127 -> 64ms poll, low cpu load
bmAttributes=3 (interrupt), bIntervall=128..255 -> 128ms poll, low cpu load
winxp:
bmAttributes=2 (bulk), bIntervall don't care -> permanent poll, high cpu load
bmAttributes=3 (interrupt), bIntervall don't care -> 8ms poll, low cpu load
So I think it's best to use
bmAttributes=3 (interrupt), bIntervall=2
this gives fastest access for linux and no heavy load for win.
Ciao Martin
P.S.: mac users - please test