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by lb
Thu Apr 05, 2012 3:51 pm
Forum: General discussion
Topic: Raspberry pi datasheet ?
Replies: 32
Views: 10009

Re: Raspberry pi datasheet ?

<t>I think OP's question is valid. While it isn't completely clear what a datasheet should describe, and in how much detail, the current documentation isn't satisfactory. There's various tidbits of information scattered throughput the forums and blog, then there's the (unofficial) Wiki and the incom...
by lb
Thu Apr 05, 2012 3:13 pm
Forum: General discussion
Topic: Raspberry pi datasheet ?
Replies: 32
Views: 10009

Re: Raspberry pi datasheet ?

There is no official datasheet available.
by lb
Sun Apr 01, 2012 4:57 pm
Forum: General discussion
Topic: USB 3.0
Replies: 16
Views: 14960

Re: USB 3.0

No.
by lb
Thu Mar 29, 2012 10:11 am
Forum: General discussion
Topic: Raspberry Pi compared to...
Replies: 20
Views: 4452

Re: Raspberry Pi compared to...

@ProDigit

The Raspberry Pi will not perform anywhere near a contemporary x86 dualcore, not in synthetic benchmarks, nor in practice. It will be far slower and much more sluggish than a first-generation Intel Atom. Sorry, but you're suffering from some serious wishful thinking.
by lb
Mon Mar 26, 2012 8:24 am
Forum: General discussion
Topic: Pi as Video player;software?
Replies: 30
Views: 8836

Re: Pi as Video player;software?

Is it possible to efficiently let the video decoder render into OpenGL textures, or to efficiently convert the decoded frames into textures? Many simple postprocessing steps can be done with OpenGL easily.
by lb
Sun Mar 25, 2012 4:57 pm
Forum: General discussion
Topic: HDMI + Analog audio?
Replies: 12
Views: 3162

Re: HDMI + Analog audio?

PWM DA conversion is fine, but I think the low-pass filter on the Pi might not have the best quality. Anyway, we won't know until we have the devices in our hands.
by lb
Sun Mar 25, 2012 4:53 pm
Forum: General discussion
Topic: Post your estimated arrival dates
Replies: 323
Views: 53321

Re: Post your estimated arrival dates

<t>More importantly, the first run was supposed to end up in the hands of tinkerers, developers and testers, to work out the kinks and issues of software and hardware. If they're held back like that, it will be quite harmful for the later educational launch.<br/> <br/> In other news, Farnell told me...
by lb
Sun Mar 25, 2012 12:46 pm
Forum: General discussion
Topic: Android for Pi
Replies: 35
Views: 25532

Re: Android for Pi

Actually there is not much divergence between Android's Linux kernel and the vanilla Linux kernel. The subsystems used by Android have been merged. The latest vanilla kernel version can run Android userspace.
by lb
Mon Mar 12, 2012 8:41 pm
Forum: General discussion
Topic: "Real-life" bandwidth available on the USB controller
Replies: 15
Views: 2907

Re: "Real-life" bandwidth available on the USB controller

Hmm, I can't find these numbers now... but I think what's missing from these figures was how Ethernet and a USB HDD or whatever perform if they're used concurrently. Say, if the Pi is used as a NAS, in this case both Ethernet and the USB HDD are used at the same time, obviously.
by lb
Mon Mar 12, 2012 8:24 pm
Forum: General discussion
Topic: How slow is it?
Replies: 113
Views: 19956

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: 19956

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: 52464

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: 52464

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: 52464

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: 2282

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: 7777

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: 7777

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: 24390

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: 24390

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: 8869

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: 1107

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: 8869

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: 8869

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: 8869

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: 23841

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...

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