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by lb
Mon Mar 12, 2012 8:24 pm
Forum: General discussion
Topic: How slow is it?
Replies: 113
Views: 24860

Re: How slow is it?

If you don't know how fast a Pentium II is, you probably know Intel Atom netbooks. Imagine an Intel Atom at 300-400 MHz, e.g. one quarter to one fifth of its regular speed.
by lb
Mon Mar 12, 2012 7:54 pm
Forum: General discussion
Topic: How slow is it?
Replies: 113
Views: 24860

Re: How slow is it?

<t>DaQatz said:<br/> <br/> <br/> I don't know where people got this number but it's inaccurate. On a "mhz to mhz" scale that performance belongs more in the ARMv3 generations. The raspberry pi is an arm11(ARMv6) and performs fairly well "mhz to mhz" next to the x86 cpu's.<br/> <br/> <br/> No, it doe...
by lb
Fri Feb 24, 2012 11:41 pm
Forum: General discussion
Topic: GPGPU on the R-PI.
Replies: 75
Views: 58653

Re: GPGPU on the R-PI.

<t>tufty said:<br/> <br/> <br/> I'd be interested in hearing what you think is missing from OpenGL ES 2 that would stop it being useful for GPGPU work.  It's been a while since I've done any myself, and I've not tried porting any of my code over to ES, but I can't see anything that's fundamentally l...
by lb
Fri Feb 24, 2012 2:42 pm
Forum: General discussion
Topic: GPGPU on the R-PI.
Replies: 75
Views: 58653

Re: GPGPU on the R-PI.

<t>mole125 said: <br/> <br/> <br/> Does it provide enough of an API to do GPU accelerated encoding/decoding of video using the generic portions of the chip (not the custom silicon) if so presumably it is then the people distributing that code who would have to worry about patant licensing not the fo...
by lb
Fri Feb 24, 2012 2:37 pm
Forum: General discussion
Topic: GPGPU on the R-PI.
Replies: 75
Views: 58653

Re: GPGPU on the R-PI.

OpenGL ES 2.0 is definitely NOT a viable option for GPGPU computing. Pretty much all of the features that make OpenGL 3.x+ capable of (somewhat) flexible and fast general-purpose computing are missing in OpenGL ES.
by lb
Sat Feb 18, 2012 11:21 am
Forum: General discussion
Topic: Sound generation for a synth app-should I OpenMax?
Replies: 11
Views: 2727

Re: Sound generation for a synth app-should I OpenMax?

I don't understand how you want to benefit from OpenMAX in your application. Raspberry Pi supports OpenMAX IL, and that basically provides a standardized API to various video codecs. No more, no less.
by lb
Wed Feb 15, 2012 11:02 am
Forum: General discussion
Topic: What kind of HDMI cable? Is 1600x900 OK? Hi10P?
Replies: 26
Views: 8819

Re: What kind of HDMI cable? Is 1600x900 OK? Hi10P?

<t>st599 said: <br/> <br/> <br/> It's quite often used by broadcasters, just not in the Direct to Home part of the workflow.. It provides better coding efficiency and allows much better grades.  It needs nowhere near double the bitrate.<br/> <br/> <br/> I think James refers to the fact that the deco...
by lb
Wed Feb 15, 2012 10:32 am
Forum: General discussion
Topic: What kind of HDMI cable? Is 1600x900 OK? Hi10P?
Replies: 26
Views: 8819

Re: What kind of HDMI cable? Is 1600x900 OK? Hi10P?

Hi10P is quite effective for avoiding certain artefacts and improves coding efficacy. However, it complicates decoding and display, and is only used by few video encoding nerds/otakus. I doubt it will be supported by any hardware decoders in the near future.
by lb
Wed Feb 15, 2012 10:08 am
Forum: General discussion
Topic: GPIO Programming Question
Replies: 59
Views: 26536

Re: GPIO Programming Question

I don't understand why you guys are so fixed on Arduino. Just use a plain AVR (or PIC, or MSP430). There's not much circuitry required to get it going and to program it.
by lb
Mon Feb 13, 2012 7:04 pm
Forum: General discussion
Topic: GPIO Programming Question
Replies: 59
Views: 26536

Re: GPIO Programming Question

<t>Python is completely unsuitable for anything that requires predictable timing. Use C and avoid dynamic memory allocations for better results.<br/> <br/> However, if you have hard realtime requirements, the RPi is no good at all. Even with Linux RT extensions (which aren't ported at this time, I s...
by lb
Sun Feb 12, 2012 2:22 pm
Forum: General discussion
Topic: CPU 20% slower than BeagleBoard?
Replies: 21
Views: 10019

Re: CPU 20% slower than BeagleBoard?

<t>Chromatix said: <br/> <br/> <br/> Some relevant points:<br/> <br/> 1) Many "general purpose" applications make absolutely zero use of NEON.  So the Cortex-A8 gets a boost from that *only* with specially optimised applications or libraries.<br/> <br/> 2) Both Cortex-A8 and the R-Pi have a VFP of s...
by lb
Sun Feb 12, 2012 1:46 pm
Forum: General discussion
Topic: Speed of the SD- card
Replies: 2
Views: 1223

Re: Speed of the SD- card

<t>Apparently (see the published datasheet) the SD interface of the BCM2835 supports UHS speeds, up to 104 MB/s. We don't know yet if the electric characteristics of the RPi will allow it to work, so that it works in practice.<br/> <br/> That said, even at standard SD 1.1 interface speeds, it' is ve...
by lb
Sat Feb 11, 2012 5:00 pm
Forum: General discussion
Topic: CPU 20% slower than BeagleBoard?
Replies: 21
Views: 10019

Re: CPU 20% slower than BeagleBoard?

<t>If the 20% is against the first revision of the original BeagleBoard, it does indeed make sense, since it's clocked at 500 MHz by default. However the current revision of the BeagleBoard is clocked at 720 MHz, and I thought that was the base for the 20% claim. Anyway, would be nice to see this cl...
by lb
Fri Feb 10, 2012 7:23 pm
Forum: General discussion
Topic: CPU 20% slower than BeagleBoard?
Replies: 21
Views: 10019

Re: CPU 20% slower than BeagleBoard?

What benchmarks, and how they were done. The hardware is known and it's also pretty well known that Cortex-A8 is a massive improvement over ARM11 in performance. I think the benchmarks might be flaky and/or not reflect real-world performance.
by lb
Fri Feb 10, 2012 7:09 pm
Forum: General discussion
Topic: CPU 20% slower than BeagleBoard?
Replies: 21
Views: 10019

Re: CPU 20% slower than BeagleBoard?

<r>According to [1] the CPU of the Raspberry Pi is merely 20% slower than the BeagleBoard"s CPU. Isn"t that a bit overly optimistic? What is this number based on? I think it is important to give the public a realistic impression of performance, there are enough misconceptions about the Raspberry Pi ...
by lb
Sat Feb 04, 2012 12:37 pm
Forum: General discussion
Topic: Can i use raspberry pi mainly for web browsing?
Replies: 62
Views: 29210

Re: Can i use raspberry pi mainly for web browsing?

<t>dom said:<br/> <br/> <br/> You will get docs and example code. DMA won"t do masks and blends.<br/> Is EXA supported by lxde?<br/> <br/> I assume this all has to be done in an immediate mode? (i.e. the ARM must be able to directly read the current pixels from framebuffer at any time)? If that is n...
by lb
Sat Feb 04, 2012 1:29 am
Forum: General discussion
Topic: Can i use raspberry pi mainly for web browsing?
Replies: 62
Views: 29210

Re: Can i use raspberry pi mainly for web browsing?

dom, if the 2D engine is really quite capable, it should be easy to come up with a full-featured EXA driver that covers all basic hooks (Solid, Copy, Composite, UTS, DFS). That's enough to get speedy 2D, for the most part.

Can we have docs for this?
by lb
Fri Feb 03, 2012 5:47 pm
Forum: General discussion
Topic: Can i use raspberry pi mainly for web browsing?
Replies: 62
Views: 29210

Re: Can i use raspberry pi mainly for web browsing?

<t>A serious problem is the lack of an X.org DDX driver for the Pi. Without any 2D acceleration, browsing the web is bound to be sluggish, especially scrolling and animations will be slow. That said even with all graphics acceleration bits in place and working fast, you won't see desktop-like or eve...
by lb
Sun Jan 29, 2012 7:40 pm
Forum: General discussion
Topic: OpenGL ES extensions and limits
Replies: 14
Views: 20557

Re: OpenGL ES extensions and limits

<r>Can someone what a Pi in their possession please compile (gcc -o eglinfo eglinfo.c -lEGL -lGLESv2) and run this program?<br/> <br/> <URL url="http://pastebin.com/Vnje5sEe">http://pastebin.com/Vnje5sEe</URL><br/> <br/> This works fine on my netbook with Mesa EGL and OpenGL ES 2.0, and hopefully it...
by lb
Sun Jan 29, 2012 4:15 pm
Forum: General discussion
Topic: Can android os be ported
Replies: 25
Views: 9446

Re: Can android os be ported

<t>JamesH said: <br/> <br/> <br/> I'm of the opinion that ICS will be too much, and Gingerbread is the best option. But I think it will be pretty slow, and difficult to architect in the hardware acceleration for graphics since gingerbread doesn't use OpenGL/VG, so you need some sort of wrapper. A bi...
by lb
Sun Jan 29, 2012 2:41 pm
Forum: Off topic discussion
Topic: Rant: Netbooks were better three years ago
Replies: 32
Views: 10505

Re: Rant: Netbooks were better three years ago

<t>nobbit said:<br/> <br/> <br/> What I want in a netbook:<br/> 9-10" size. Bigger than that and it"s not for me.<br/> At least 900 MHz. Lower might work, but I don"t think so.<br/> 1 GB RAM. I"ve never needed more on the one I have.<br/> 20 GB SSD. Again, never needed more on the one I have.<br/> M...
by lb
Sun Jan 29, 2012 2:32 pm
Forum: General discussion
Topic: Does the soc have hardware encryption acceleration?
Replies: 9
Views: 6012

Re: Does the soc have hardware encryption acceleration?

Are export restrictions for cryptography still an issue? That's quite silly... I remember this stopped being a problem, at least for web browsers, in the late 90s?
by lb
Sun Jan 29, 2012 2:26 pm
Forum: General discussion
Topic: OpenGL question
Replies: 12
Views: 4040

Re: OpenGL question

<t>You don't need an OpenGL ES "emulator" to write OpenGL ES code on a desktop machine. OpenGL ES 2.0 is almost completely a subset of OpenGL 3.2, and if you stick to the subset ES 2.0 implements, you're usually fine. Moreover, most desktop GL implementations include the GL_ARB_ES2_compatibility ext...
by lb
Sun Jan 29, 2012 2:05 pm
Forum: General discussion
Topic: OpenGL ES extensions and limits
Replies: 14
Views: 20557

Re: OpenGL ES extensions and limits

<t>JamesH said:<br/> <br/> <br/> I think this has been asked before, and I seem to remember  posting the results on glGetString returns. Try a forum search. <br/> <br/> <br/> <br/> I did search the forums of course, but didn"t find anything. Now I did another query for "glGetString" and that did it....
by lb
Sat Jan 28, 2012 8:28 pm
Forum: General discussion
Topic: For those looking for a mediaplayer only
Replies: 80
Views: 24316

Re: For those looking for a mediaplayer only

I think there is some merit to OP's suggestion.

That is, if you need a gadget that just works as a small HTPC-like video player, without fiddling around and a lot of work by yourself, Raspberry Pi is definitely not the right device to get, especially not in this early stage.

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