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by Heater
Tue May 21, 2013 10:05 pm
Forum: General discussion
Topic: Something the Pi is not good at - calculating Pi
Replies: 175
Views: 35649

Re: Something the Pi is not good at - calculating Pi

OtherCrashOverride, ...possibly behead and burn it [this thread] No, why? On the one hand we have a guy presenting a program he created in school to calculate a million digits of pi. Perhaps more years ago ago than most Pi users have been alive. An algorithm that has worked on more generations of ha...
by Heater
Tue May 21, 2013 3:25 pm
Forum: General discussion
Topic: Something the Pi is not good at - calculating Pi
Replies: 175
Views: 35649

Re: Something the Pi is not good at - calculating Pi

Just had to see it for myself.
Yep, gmp-chudnovsky can generate a million digits of pi in 17.9 seconds on my Pi.
Amazing.

Meanwhile on my 2GHz Intel PC that is 1.7 seconds.
by Heater
Tue May 21, 2013 2:33 pm
Forum: General discussion
Topic: Maker Fairey Tales - NOOBS and Pidora and Wayland, Oh My!
Replies: 53
Views: 17632

Re: Maker Fairey Tales - NOOBS and Pidora and Wayland, Oh My

OtherCrashOverride,
I think that is the major point of misconception. None of those 'are the problem'.
Oh good. It's not just me. None of us knows what this Wayland thing is good for. Perhaps those that do can't explain it.

Bottom line is I still don't know.
by Heater
Tue May 21, 2013 12:32 pm
Forum: General discussion
Topic: Something the Pi is not good at - calculating Pi
Replies: 175
Views: 35649

Re: Something the Pi is not good at - calculating Pi

Jim, ...nice thinking so far outside the box that you need the Hubble Space Telescope to look back and see the box! You have a brash, overbearing, offensive, rude, elitist, politically incorrect, arrogant ...(should I go on?)...style. However, that statement above has to be the nicest things anyone ...
by Heater
Tue May 21, 2013 8:51 am
Forum: General discussion
Topic: Something the Pi is not good at - calculating Pi
Replies: 175
Views: 35649

Re: Something the Pi is not good at - calculating Pi

What is the criteria for "good" platform for calculating Pi. My PC can get a million digits in 2 seconds. The Pi perhaps in 20 seconds. You might say the PC is better on the grounds of sheer speed. BUT: 1) What about power consumption? I leave it as an exercise for the reader to calculate the relati...
by Heater
Tue May 21, 2013 6:18 am
Forum: General discussion
Topic: ext3/4 and SD-card wear leveling
Replies: 134
Views: 63522

Re: ext3/4 and SD-card wear leveling

In my experience SD cards are really unreliable. As noted in a previous post above. There are many problems that can get compounded: 1) ext3 files system does not like unclean shutdowns. That is having the power yanked or system crash whist it has data that has not been synced from RAM to disk. It i...
by Heater
Tue May 21, 2013 6:07 am
Forum: General discussion
Topic: ext3/4 and SD-card wear leveling
Replies: 134
Views: 63522

Re: ext3/4 and SD-card wear leveling

speculatrix2, if you can't trim a flash drive, writing ones to it like this will allow most flash controllers to mark blocks as unused: I have a hard time believing this. How can the flash controller in the SD card know that those blocks I have written ones to are unused as opposed to blocks that I ...
by Heater
Mon May 20, 2013 7:59 pm
Forum: General discussion
Topic: testing sdhc read/write speeds
Replies: 3
Views: 2839

Re: testing sdhc read/write speeds

The command: $ sync; time dd if=/dev/zero of=~/test.tmp bs=500K count=1024; time sync Starts out by doing "sync" which flushes any data that should be on disk, but is still in memory, to disk. Then it runs "dd" under the "time" command. This writes a load of stuff to test.tmp and tells you how long ...
by Heater
Mon May 20, 2013 7:21 pm
Forum: General discussion
Topic: Something the Pi is not good at - calculating Pi
Replies: 175
Views: 35649

Re: Something the Pi is not good at - calculating Pi

Jim, For an ex-military guy who is used to the rough and tumble of the barracks you are a very touchy, sensitive, if not paranoid guy. That is to say there is no "hate" here only a discussion about possibilities. When you say, "I still stand by my statement that most people aren't even thinking abou...
by Heater
Mon May 20, 2013 3:17 pm
Forum: General discussion
Topic: Something the Pi is not good at - calculating Pi
Replies: 175
Views: 35649

Re: Something the Pi is not good at - calculating Pi

I suspect there must be uses for the GPU outside of getting stuff onto the screen. If I understand correctly they should be useful for matrix multiplication, for example. There is still a question mark over how fast you can get data in / results out though and if that cancels any gains to be had fro...
by Heater
Mon May 20, 2013 2:27 pm
Forum: General discussion
Topic: Something the Pi is not good at - calculating Pi
Replies: 175
Views: 35649

Re: Something the Pi is not good at - calculating Pi

He was wrong. What that says about us being ''stoopid' is not so clear though:) P.S. Wrong that is until he or someone else proves otherwise by investing an enormous amount of time and effort into making use of the GPU to calculate pi. Even then I don't see any major (order of magnitude) gains to be...
by Heater
Mon May 20, 2013 1:00 pm
Forum: General discussion
Topic: Maker Fairey Tales - NOOBS and Pidora and Wayland, Oh My!
Replies: 53
Views: 17632

Re: Maker Fairey Tales - NOOBS and Pidora and Wayland, Oh My

OtherCrashOverride. Remoting the display is trivial. So trivial that MS Windows could do it until about Windows 2000. Unix machines had been doing it with the X Windows System since about 1984. This is already done in current X11 using VNC Remote display of X11 apps does not require VNC. X11 is itse...
by Heater
Mon May 20, 2013 12:01 pm
Forum: General discussion
Topic: Maker Fairey Tales - NOOBS and Pidora and Wayland, Oh My!
Replies: 53
Views: 17632

Re: Maker Fairey Tales - NOOBS and Pidora and Wayland, Oh My

So now I'm worried. Are we about to retrograde from network transparent display back to Windows style "you can only see it on the machine its running on". All for the sake of some prettier graphics. I hope not. But that link goes on to say: This doesn't mean that remote rendering won't be possible w...
by Heater
Mon May 20, 2013 11:50 am
Forum: General discussion
Topic: 22/7
Replies: 32
Views: 4482

Re: 22/7

jtb, 22/7 is not Pi day. From wikipedia we learn that "Pi Day is observed on March 14 (or 3/14 in the month/day date format)" http://en.wikipedia.org/wiki/Pi_Day So you have missed it for this year. However there are those you argue that Pi is the wrong constant to hold in high regard anyway and the...
by Heater
Mon May 20, 2013 11:36 am
Forum: General discussion
Topic: Maker Fairey Tales - NOOBS and Pidora and Wayland, Oh My!
Replies: 53
Views: 17632

Re: Maker Fairey Tales - NOOBS and Pidora and Wayland, Oh My

Err... yeah. So can apps using wayland be run on machine A whilst their display is on machine B with a network in between?
by Heater
Mon May 20, 2013 11:25 am
Forum: General discussion
Topic: Something the Pi is not good at - calculating Pi
Replies: 175
Views: 35649

Re: Something the Pi is not good at - calculating Pi

Bakul Shah, Takuya Ooura's pi_css5 program on the Raspi computes the first million digits of Pi in under 79 seconds (compared to under 3s on a 3.6Ghz AMD FX). So I'd say the Raspi is plenty fast! Very good. But I have a program here that will generate the first million digits of pi on an ARM Cortex ...
by Heater
Mon May 20, 2013 10:31 am
Forum: General discussion
Topic: Maker Fairey Tales - NOOBS and Pidora and Wayland, Oh My!
Replies: 53
Views: 17632

Re: Maker Fairey Tales - NOOBS and Pidora and Wayland, Oh My

Jim, You have lots of interesting news there. Which prompts a lot of questions: The Wayland thing sounds great. One thing I have always wondered though is "Does it maintain operation over a network like X11 does?" ...education market which is largely not happy at all with the transition to Windows i...
by Heater
Sun May 19, 2013 9:33 am
Forum: General discussion
Topic: Raspberry Pi's as electronic encyclopedias?
Replies: 6
Views: 1000

Re: Raspberry Pi's as electronic encyclopedias?

Well. you can make a start with a download of the wikipedia data base.
Only 10GB compressed or 40 odd GB uncompressed.
http://en.wikipedia.org/wiki/Wikipedia: ... e_download
by Heater
Sat May 18, 2013 5:59 pm
Forum: General discussion
Topic: Something the Pi is not good at - calculating Pi
Replies: 175
Views: 35649

Re: Something the Pi is not good at - calculating Pi

If we step back from specific hardware for a moment. The problem at hand here is calculating a million or billion or whatever huge number of digits of Pi. Clearly we wanted 16 bit integers when we had 8 bit CPUs. Then we wanted 32 bit integers when we had 16 bit CPUs. Now we use 64 bit integers on 6...
by Heater
Sat May 18, 2013 2:21 pm
Forum: General discussion
Topic: Something the Pi is not good at - calculating Pi
Replies: 175
Views: 35649

Re: Something the Pi is not good at - calculating Pi

OtherCrashOverride, The moral of the story is that the entire stack from OS to browser is very resource demanding. The web today is not designed for systems with 512MB of memory. When dealing with graphics and GPU resources, you will find you run out of memory much quicker. I see your point. But I'm...
by Heater
Sat May 18, 2013 1:18 pm
Forum: General discussion
Topic: Something the Pi is not good at - calculating Pi
Replies: 175
Views: 35649

Re: Something the Pi is not good at - calculating Pi

OtherCrashOverride, It would probably actually take WebGL being implemented on the RPi before many would understand why it would be of little value. I'm curious, why do you think that? We can have slow browsers with little in in the way of graphical animation possibilities or we can make use of the ...
by Heater
Sat May 18, 2013 10:53 am
Forum: General discussion
Topic: Something the Pi is not good at - calculating Pi
Replies: 175
Views: 35649

Re: Something the Pi is not good at - calculating Pi

@Jim, There are a couple of flaws in this whole "hack on the GPU" plan. Well, one really but it spawns others. The GPU is a totally closed off chunk of hardware that is unique to Broadcom. So, any hacks into it to make use of it's maths prowess are going to only be of use on the Pi. I can't see anyo...
by Heater
Fri May 17, 2013 6:52 pm
Forum: General discussion
Topic: Something the Pi is not good at - calculating Pi
Replies: 175
Views: 35649

Re: Something the Pi is not good at - calculating Pi

Jim, This sounds promising, sounds like you have the ear of people in the right places. Applying your charm and social graces to those ears might get us some fast GPU maths possibilities. However I'd be ecstatic with getting webgl working. As you said Google have done wonders with their V8 JavaScrip...
by Heater
Fri May 17, 2013 1:32 pm
Forum: General discussion
Topic: Something the Pi is not good at - calculating Pi
Replies: 175
Views: 35649

Re: Something the Pi is not good at - calculating Pi

pluwash,

Double precision float gives us 53 bits of mantissa which can be in integer calculations performed by the FPU. Which is what JavaScript does. That munches more bits per instruction for us. I have no idea how the timing works out though.

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