I've built my own SMD board using the atmega328-au and I've just programmed it up with an ISP but everything seems to be running slow. Running the blink example is about 16x slow. Is it for some reason using the internal clock? I've tried all the different board options, but still no luck. I'm really confused here!! Any help/ideas would be appreciated.
The factory chips are set to use the 8 MHz internal clock AND set the default clock pre-scale to /8 giving a CPU speed of 1 MHz.
Didn't you burn a bootloader using the Arduino IDE? That will set the fuses correctly for external 16 MHz crystal/resonator.
Ahhhah. Thanks so much for the fast reply! I'm so happy it's not something I screwed up in the PCB!!