Why is everything slow


13 posts
by tlink98 » Sun Jun 24, 2012 10:06 pm
Quick question for you all. i recently got my pi and have run about most of the images available for it and they all run slow and not everything is supported. Why is the support for the pi lacking? It has been in development for about 6 years and no one has developed stable operating systems that work 100%! if anyone has an answer to this question or has a solution to the lack of OS support, reply to this subject. Thanks :D
Posts: 2
Joined: Sun Jun 24, 2012 7:33 am
by Vindicator » Sun Jun 24, 2012 10:58 pm
The hardware has been in development for 6 years not the software and until recently there has not been enough hardware for the software development to progress, and realize that the CPU of the Raspi is about the equivalent of a Pentium 3 300Mhz so I do not know why some seem to expect more from a 35.00 computer.
The GPU is very capable but is still not completely supported for all apps, there is a long way to go and it will never replace a regular desktop system nor is it meant to do so.
ARM in general is not that well supported by most OSes but is gaining more support as more ARM devices are available and hundreds of thousands of Raspi's that are going to be sold is going to help.
If you are more worried about ,spelling, punctuation or grammar you have probably already missed the point so please just move on.
User avatar
Posts: 314
Joined: Sat Sep 17, 2011 11:10 pm
Location: Susanville Ca USA
by abishur » Mon Jun 25, 2012 4:53 pm
To be fair, the OSes are stable, even the GUI is stable, it's just that it isn't making use of the GPU so it's not accelerated. A further issue is that there are ongoing efforts to make it stable for all the various peripheral combinations out there. It's a process.

It's a little odd though. I mean you clearly have done some research to know that the pi in general has been in development for 6 years, but you somehow missed that the actual current design (that is using the Broadcom SoC) has been... what a year and half? Two years?

You also somehow missed the comments that have been repeated ad nauseum discussing the fact that it still is in a development state.

I'm not trying to pick on you or anything, it just seems weird to both clearly posses knowledge that usually comes from reading around on the site, and at the same time exhibit a lack of knowledge that is impossible to posses if you spend any time at all on the site. :?
Dear forum: Play nice ;-)
User avatar
Moderator
Moderator
Posts: 4225
Joined: Thu Jul 28, 2011 4:10 am
Location: USA
by bcrtt » Tue Jun 26, 2012 8:45 pm
On the issue of speed, this could be due to the card you are currently using. All cards will operate differently and at different speeds, which can make a major difference because the entire os needs to be loaded from it. Please check the wiki for a list of working (and non working) cards, and other currently supported peripherals.
http://elinux.org/RPi_VerifiedPeripherals
Posts: 4
Joined: Tue Jun 26, 2012 8:24 pm
by tlink98 » Tue Jun 26, 2012 10:54 pm
I now understand guys. Also about the making fun of thing , no offense was taken. Hopefully i have time to tinker with the codes.
Posts: 2
Joined: Sun Jun 24, 2012 7:33 am
by mahjongg » Tue Jun 26, 2012 11:35 pm
here is a list of things that make the RPI seem even slower than its 700MHz ARM CPU should indicate, all because many of the hardware capabilities aren't yet used by the software:

* No hardware for floating point calculations is yet used, although the hardware is capable of it.
* No acceleration of drawing the GUI is done, although the GPU is capable of it.
* No integrated support for acceleration of video and audio decoding, only a single decoder is (H.264) is supported in hardware, and only a few programs use it. Even MP3 has no hardware decoding support as of yet.
* The USB drivers are not optimized, and use about 20% of the CPU, even for simple keyboard and mouse support. But Ethernet communication is also run though USB and is therefore very CPU intensive.
* many drivers are still beta, including sound drivers.
* Linux on ARM is still relatively new, so many optimisations that are common for x86 are still not fully developed for ARM.


P.S, The above is actual AFAIK, please correct me if I'm wrong.
User avatar
Moderator
Moderator
Posts: 4506
Joined: Sun Mar 11, 2012 12:19 am
by JeremyF » Tue Jun 26, 2012 11:53 pm
mahjongg wrote:here is a list of things that make the RPI seem even slower than its 700MHz ARM CPU should indicate, all because many of the hardware capabilities aren't yet used by the software:

* No hardware for floating point calculations is yet used, although the hardware is capable of it.
* No acceleration of drawing the GUI is done, although the GPU is capable of it.
* No integrated support for acceleration of video and audio decoding, only a single decoder is (H.264) is supported in hardware, and only a few programs use it. Even MP3 has no hardware decoding support as of yet.
* The USB drivers are not optimized, and use about 20% of the CPU, even for simple keyboard and mouse support. But Ethernet communication is also run though USB and is therefore very CPU intensive.
* many drivers are still beta, including sound drivers.
* Linux on ARM is still relatively new, so many optimisations that are common for x86 are still not fully developed for ARM.


P.S, The above is actual AFAIK, please correct me if I'm wrong.

Actually the free codec Xvid also works accelerated as well as H.264 .
{sig} Setup: Original version Raspberry Pi (B, rev1, 256MB), Dell 2001FP monitor (1600x1200), 8GB Class 4 SD Card with Raspbian and XBMC, DD-WRT wireless bridge
Posts: 522
Joined: Wed Jan 25, 2012 9:06 pm
by Bakul Shah » Wed Jun 27, 2012 7:14 pm
Vindicator wrote:the CPU of the Raspi is about the equivalent of a Pentium 3 300Mhz.

IIRC, even the lowest speed Pentium 3 had 16KB+16KB L1 cache which ran at cpu speed and 256K to 512KB L2 cache which ran full to half cpu speed depending on the model. I think ARM1176 in BCM2835 has a L1 cache only (16KB+16KB? I can't find a definitive answer). A lack of L2 cache can impact performance quite a bit.
Posts: 291
Joined: Sun Sep 25, 2011 1:25 am
by mahjongg » Fri Jun 29, 2012 12:17 am
Its not a direct comparison with any pentium PC (that would be impossible), its more a hands on comparison based on attempts to run the same (but obviously recompiled for the platform) software on both systems. But there is actually a big improvement possible for the R-PI with better software for it.
User avatar
Moderator
Moderator
Posts: 4506
Joined: Sun Mar 11, 2012 12:19 am
by HashberryPee » Fri Jul 06, 2012 7:44 am
So which distribution is to recommend right now according speed and stability?
Debian, the only one I tried yet, is pretty slow. Heard that arch should work better
User avatar
Posts: 54
Joined: Thu Apr 05, 2012 9:41 am
Location: Germany
by startreksteve » Fri Jul 06, 2012 8:08 am
So if USB keyboards and mice hog 20% cpu, its a big plus to SSH in without either then, 20% extra cpu! Woohoo!
This was my plan from the beginning.
Posts: 43
Joined: Tue Mar 13, 2012 10:23 am
by mahjongg » Fri Jul 06, 2012 8:37 am
Yes, but its thinkable that the USB stack keeps on using CPU time even when no USB devices are used, so perhaps you need to kill the USB driver to get the speed increase.
User avatar
Moderator
Moderator
Posts: 4506
Joined: Sun Mar 11, 2012 12:19 am
by jamesh » Fri Jul 06, 2012 8:39 am
Remember that the ethernet is connect via USB....

And there is an L2 cache.

And I think Raspbian is the current fastest distro, but that's still alpha. Debian Wheezy is next best I believe.

It's likely Raspian will become the recommended distro as its performance is so much better, just needs to get some testing under its belt.
Moderator
Moderator
Posts: 10580
Joined: Sat Jul 30, 2011 7:41 pm