What makes the Prime so fast?

[jte]

(02-20-2016 03:11 PM)debrouxl Wrote:  The primary factor in the Prime's speed is indeed the raw CPU speed. Secondary factors are probably that Bernard Parisse and HP didn't screw up the implementation too much. …

While I usually think, for some comments, it's better for me to make like a duck and let them slide like water off a duck's back, occasionally the duck has to rearrange his feathers.

There's a whole host of issues in getting a working product out to market. The HP team and Bernard are doing a good job. It's very easy to underestimate the amount of issues that can arise, and the size of the beast. To put it in perspective: I help out here and there, and a quick look at the code base turns up >40,000 lines of code in a handful-ish of files I'm the author of. Some implementation bugs have been discussed on this list: if I recall correctly, a grand total of one (1) of these bugs was in code I've put in. (A few+ more have slipped by me, and found elsewhere, but the parts I work on typically aren't popular topics on this board.) This might give a hint at the complexity of the code base: the % of lines with bugs in them has to be incredibly low to get the bug count down. (Some design decisions that should, ideally, eventually, be re-visited / addressed have also been touched on here.)

A fair amount of the code is pretty tight (in some ways) as it was designed with the limits of the 39gII in mind. For example: the Function app currently doesn't employ any offscreen buffers of note in standard plotting / scrolling etc. Things like the signed area display, the tangent line, the marching ants, etc. all rely on colour permutations that can be undone without using any additional memory beyond the screen buffer itself. Changing some of this code to better utilize the increased resources of the Prime is an obvious thing to do, (it would allow for increased speed at the cost of greater memory use) but it takes time and effort… (I mention the Function app view as that's what I'm familiar with, but other parts are similarly parsimonious with resource consumption as it all had to work within the 39gII's limits.)