Middle
Posts: 14
Joined: Mon Apr 16, 2012 11:39 am

Re: Been playing with a Pi for the last couple of days. General comments!

Fri Apr 20, 2012 11:40 pm

Depends what you are doing with it really, what I assume was 1080p did work but would be pretty laggy for any mildly graphically intensive things. So fine if you are just using terminals and coding, not great for web browsing.

If you can set it to a smaller resolution an d see if there is any benefit to performance!

Middle
Posts: 14
Joined: Mon Apr 16, 2012 11:39 am

Re: Been playing with a Pi for the last couple of days. General comments!

Sat Apr 21, 2012 5:32 pm

Had another good play today, unfortunately i couldn't test out someones program they sent because the link wasn't working :/

On our setup I was unable to lower the resolution on the TV from the LXDE menu and preferences, so I'm still unsure how much of a gain there is to be had from running a smaller resolution than 1080p. However I shall try to get a HDMI to DVI adapter soon so we can try out smaller monitors.

Running at 1080p with 25% of RAM as video RAM and the older version of Debian I was using really isn't practical at all unfortunately, it takes a good two minutes for Firefox to load up alone!

However I did manage to get glxgears running after trying to find "That cogs program" for about an hour before realising it was gears not cogs!

I ran started the glxgears program from .xinitrc so that it would have the most power available to it, and from there it got 16 FPS max, I then started up LXDE and ran a prime number program and glxgears, the prime number program performed at very nearly the same speed as before (Taking 58 seconds to find all the prime numbers under 100,000) and glxgears went down to 8 FPS.

Then I started playing about with getting Lynx and Vim installed so I could effectively play without LXDE running! Didn't take that long to get it all setup and I was soon messing around with Perl (My weapon of choice), and everything seemed to run a lot smoother and happier!

Just some more observations, hope they were of some use to someone!

rkn704
Posts: 41
Joined: Sun Dec 30, 2012 4:25 pm

Re: Been playing with a Pi for the last couple of days. Gene

Sun Dec 30, 2012 4:48 pm

The prime number program you are using is obviously a little more refined than the one I have just created. Does your version really find all the prime numbers up to 100,000 in 58 seconds.

The best I can get at the moment is 25 minutes for prime up to 100,000 and 78 seconds for primes up to 10,000.

I am running it via IDLE, I think it is producing the correct results. Each result is printed to the screen. I used it as a method of learning how to create loops with While and If functions. and how to use the time function.

The last few results from the 100,000 test are:
99907
99923
99929
99961
99971
99989
99991

Number of prime numbers 9592
Time elapsed in seconds 1538.99237204 (approx 25 minutes)

Please can you let me know the secret of the fundamental process that makes your version so much faster.

Thanks in advance.

Return to “General discussion”