relative throughput of new/old cRIOs

[wireties]

I have heard that the 4-slot cRIOs are faster. Is this true? Anyone know how much faster?

[EricVanWyk]

They have more memory and a better cache. It makes some use cases faster, but it isn't huge.

[Racer26]

Not enough to matter, not unless you're doing seriously high end trigonometry, triangulation, vision, and a bunch of interrupting.

Until 2009, we ran on an 8-bit microcontroller that had 4kB of RAM and 128kB of program space, operating at 10MIPS, and we did vision with that.

The cRIO runs at something on the order of 400MIPS, and has far more RAM/Program Space. If any of us start saturating its capabilities, I'll be amazed.

[wireties]

Originally Posted by 1075guy

Not enough to matter, not unless you're doing seriously high end trigonometry, triangulation, vision, and a bunch of interrupting.

like continuously calculating trajectory? continuously tracking a target using vision algorithms? running 6-8 PID loops at 50Hz? get the point?

Originally Posted by 1075guy

Until 2009, we ran on an 8-bit microcontroller that had 4kB of RAM and 128kB of program space, operating at 10MIPS, and we did vision with that.

it was the 16-bit PICC I think and the vision code was so slow as to be almost unusable - and the camera did some of the work back then

Originally Posted by 1075guy

The cRIO runs at something on the order of 400MIPS, and has far more RAM/Program Space. If any of us start saturating its capabilities, I'll be amazed.

be amazed, have you seen all the other crap running on that processor? but I basically agree, it should be enough.

[EricVanWyk]

If you want to get in to the gritty details, you can start here .

The FRC cRIO-II has twice the memory: twice the RAM, twice the FLASH, and twice the on-die cache in the processor. However, raw execution speed in the cores are (roughly) identical: both run at 400MHz and can issue up to 3 instructions per clock.

The extra memory is good for vision, but won't really affect things like trajectory calculations and PID loops. Simply put, anything that the PIC could do is trivially small on the new system. Bumping the number of PID loops from 8 to 80 would have no impact on performance, but bumping the image size from 160x120 to 640x480 certainly will.

[Racer26]

Originally Posted by wireties

it was the 16-bit PICC I think and the vision code was so slow as to be almost unusable - and the camera did some of the work back then

It was a PIC18F8722. The specs I quoted came straight from Microchip.

You are correct that the camera itself did a bunch of the work, but the imaging code wasn't particularly slow. It kept up with the camera framerate.