I think 1 image per minute is a very reasonable expectation, even without DMA.
Saving to /tmp is also the best (fastest) way to go.
> I would like to try the kernel jiffies timer experiment. How might I go about doing that?
I thought it would be as easy as just changing:
System type ---> Timer and clock configuration ---> (128) Kernel HZ (jiffies per second)
to some value like 1024...but then I'm not sure that worked at all because then i lost my MTU2 timer interrupts:
$ grep sh-mtu2 /proc/interrupts
I'll have a look to see what else I'm missing.