On Thu, Sep 3, 2009 at 10:18 AM, Robert Feld <[email protected]> wrote:
> > I'm assuming 30 fps and 32bit bus without pixel bit packing, that means > your sending roughly 332.52 MB/s on the bus which on my CPU is about 42%. > > > So you sa that there is always a full doubleword transfered per pixel? That > would be 800x480x4x60Hz= 92 MByte/s ... Or did I miss something? > > The bus AFAIK runs at 70MHz/32Bit and therefore has a max. throughput of > 280 MByte/s. That means we are using about 33%. (Atmel told us the device > will run stable up to a bus load of 50%) > > If you reduce the frame rate to 20fps > > What exactly do you mean? The refresh rate? It's a bit difficult to reduce > that as the toolkit (FLTK) we use controls a lot of the refresh logic... > > and color depth to 16 bit, then your output rate would drop to 110.83 MB/s > or 14% of the bus a significant savings. > > Or 800 x 480 x 2 Byte x 60 Hz = 46 MByte/s in my calculation... Which is > 16% of the bus capacity and therefore indeed a big saving... > > Kind regards, > Robert > > > I don't know what I was thinking with the math, its been a long week.... thanks for keeping me honest :) But you the point that I was trying to make.
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