Subject:
|
Re: another comparison
|
Newsgroups:
|
lugnet.robotics
|
Date:
|
Sun, 21 Jan 2007 12:51:03 GMT
|
Viewed:
|
3025 times
|
| |
|
|
In lugnet.robotics, Claude Baumann wrote:
> the RCX (under the custom FW of Ultimate Robolab)
> operates the sampling plus DFT 22.8 times faster
> than NXT (under "standard" FW running a bytecode
> program written with the LV Toolbox)!
I'd love to make some other comparisions; actually, some of us have been trying
to figure out a good way to do this. Part of the problem is defineing specific
"goals" for a battery of tests. A DFT (while impressive), is propably not the
best example, at least partially because I don't think anybody has tried this
complexity under, say, NXT-G: the most complex math I've done are things like
square roots and inverse trig functions. What I think we need are:
1) Processor speed: something like your DFT comparision, but easier for folks
like me who are far less talented than that example under NXT-G. Something like
a hailstone number problem (also called the (3n+1) problem), or even easier
(just adding a number to itself 10,0000 times?)
2) Sensor readings: how fast can the FW+SW combination read from a sesnor 10,000
times or similar. Note there's a difference between taking a previously stored
value saved by the FW and getting current, fresh, up-to-date values.
3) For the NXT, a way to compare the speed of updating the LCD
4) Again for the NXT, a way to compare BT message speed (one-way and
bidirectional... they (will? may?) be different), and if we want, to compare
sending the same "information" RCX-to-RCX via IR. Again, what the message sgould
be is rather up for discussion: one-byte messages are the lowest common
denominator, but the fact that you can send more efficient multi-byte (text)
messages under BT should be taken into account too.
It's not a simple problem. As recent discussions have sometimes pointed out,
folks have very different viewpoints on what is or is not a good test, or what a
"good" comparision is... and if we want a speed comparison to be as useful as
possible to the community, it needs to be fairly generally agreed upon.
So, ideas from the group? Claude, you certainly have some, and I've mentioned
some above. We really need input here from end users who "know what they want",
and certainly from the SW and FW writers (those people are going to know how to
code something in those languages as well). Dick (RobotC, RCX "fast FW"), John
(NBC, NQC, NXC), Brian (LeJos?), Ralph (pbLua), and lots of others, anybody want
to put out some input here?
> Beating the RCX is not that simple!
Given the different processor speed, and instruction set, it *should* be...
well, in my own little world where I know next to nothing about HW, or
down-to-the-metal FW issues :-) Help!
--
Brian Davis
|
|
Message has 1 Reply:
 | | Re: another comparison
|
| (...) Perhaps a good benchmark would be to write a PID controller and measure the number of control loop iterations per second that can be achieved under each environment. This incorporates sensor input with motor output, and uses a moderate amount (...) (18 years ago, 21-Jan-07, to lugnet.robotics)
|
Message is in Reply To:
| | another comparison
|
| We have compared the sampling and computing speed of NXT and RCX. NXT uses standard firmware 1.03 and is programmed with the LabVIEW toolkit. RCX is programmed with ULTIMATE ROBOLAB. Both bricks do the same thing: computing the DFT on a small (...) (18 years ago, 20-Jan-07, to lugnet.robotics)
|
11 Messages in This Thread:
  
 
- Entire Thread on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
This Message and its Replies on One Page:
- Nested:
All | Brief | Compact | Dots
Linear:
All | Brief | Compact
|
|
|
|
