user516: A Raspberry Pi is a credit card sized $25 (or $45, for the deluxe option) computer, designed for educational use. Has anyone tried running mining software on it? If so, what's the hashrate like? (apparently the CPU is approximately equivalent to a P2 300MHz - I know the hashrate will be very low!)
Also, can the GPU be used to mine? What's the hashrate for that, if it's been done.
From the FAQ on the above linked site: "The GPU provides Open GL ES 2.0, hardware-accelerated OpenVG, and 1080p30 H.264 high-profile decode.
The GPU is capable of 1Gpixel/s, 1.5Gtexel/s or 24 GFLOPs of general purpose compute and features a bunch of texture filtering and DMA infrastructure.
That is, graphics capabilities are roughly equivalent to Xbox 1 level of performance. Overall real world performance is something like a 300MHz Pentium 2, only with much, much swankier graphics."
Note: The price of $25 or $45 excludes a way of powering it (via MicroUSB), a keyboard, a mouse and likely a USB hub. I think you need to provide an SD card too.

user6016: I will step up and answer the Raspberry Pi question too. The RPI in and of itself is not worth using to do virtual currency mining on by itself. However, if you a nice powered USB hub and connect in the ASICs that plug in via the USB ports and download the proper software that can access these devices, then you've got a descent mining rig to speak of.
Note:
Due to the way in which the ASICs are designed, they can only do SHA256D and that alone although, performance per watt is the best way to go. Essentially, all the RPI does is act as the surrogate for all the ASIC slave units and constantly feeds them data and ferries the data hashes back and forth from their source.
You can't use Scrypt with these USB ASICs at all. You'll be stuck using the GETWORK protocol until someone can come up with an ASIC that can do both SHA256D and Scrypt.
One last thing, you may have heard of the Stratum protocol vs. the old GETWORK protocol. This can be used with Scrypt or SHA256D algorithms. Stratum helps you get less stale and has even better network performance than the old protocol.
Hope this clears things up like my message above.

user81238: Great summary here:
https://www.electromaker.io/blog/article/cryptocurrency-mining-on-the-raspberry-pi-60
Also includes a step-by-step guide on how to mine crypto currency on the Raspberry pi

user6016: The one thing I should probably answer on is about the difference between OpenGL / OpenGL-ES and OpenCL. Both OpenGL and OpenCl can be used for SHA256d hashing, but OpenCl is used much more frequently. 
Where as GL means Graphics Language and CL stands for Compute Language. GL is for graphics and CL is for mathematical and scientific calculations. While your system may have OpenGL support of some sort, it's more than likely doesn't have OpenCL 1 & 2 support for the GP-GPU (VideoCore IV) which would allow you to get okay to medium hash rates. As I see to remember, the VideoCore IV in the Pi doesn't support it in hardware (OpenCL version 1 or 2). 
Which means you'd have to rely on those ASIC miners that are connected via the USB port hub or even a dedicated mining rig that is connected via the UTP network connector (RJ-45 jack / Ethernet). 
Well, at least we're having a good amount of information / data coming out so the next people that read this will have a good idea on what to do with their RPIs if they want to do any mining.

user1896: It gets less than 200kh/s on the CPU proof here http://www.youtube.com/watch?v=rrdzam7voOg&list=UUdOgdYMe-hwv2_uUtYlqLDQ&index=1&feature=plcp

user22: The Raspberry Pi uses the VideoCore IV series of GPU, which to my understanding are either a single or dual core GPU running at or around 700 MHz. Since the primary benefit of GPU mining is that you can run many parallel processes on the hundreds of cores typically found in most GPUs, the single-core nature of the VideoCore GPU undoes most of that benefit.
I don't have exact numbers, nor the necessary knowledge to compute an estimate, but I can tell you that the Folding@Home folks already discussed this and came to the conclusion that an AMD Phenom II X4 940 was almost 5 times as efficient for their needs as utilizing both the CPU and GPU of the Raspberry Pi. Since the needs of Folding@Home are very similar (but not identical) to Bitcoin's, it's probably not a stretch to say that if CPU mining (admittedly with a fairly nice CPU) is 5x more efficient, the Raspberry Pi doesn't look like a strong contender.
Of course, until we have solid MH/s and actual at-the-wall wattage numbers it's very difficult to say if, at scale, a cluster of $35 Raspberry Pis could compete with other setups on initial price or power cost. Personally, I'd guess not.

user3388: There is a nice wiki page here: https://en.bitcoin.it/wiki/Mining_hardware_comparison
The raspberry pi is listed by its processor in the arm section: ARM1176JZ(F)-S. It gets 0.2 Mhash/s when clocked at 800 MHz.

516: <p>A <a href="http://www.raspberrypi.org/" rel="noreferrer">Raspberry Pi</a> is a credit card sized $25 (or $45, for the deluxe option) computer, designed for educational use. Has anyone tried running mining software on it? If so, what's the hashrate like? (apparently the CPU is approximately equivalent to a P2 300MHz - I know the hashrate will be very low!)</p>
<p>Also, can the GPU be used to mine? What's the hashrate for that, if it's been done.</p>
<p>From the FAQ on the above linked site: &quot;<em>The GPU provides Open GL ES 2.0, hardware-accelerated OpenVG, and 1080p30 H.264 high-profile decode.
The GPU is capable of 1Gpixel/s, 1.5Gtexel/s or 24 GFLOPs of general purpose compute and features a bunch of texture filtering and DMA infrastructure.
That is, graphics capabilities are roughly equivalent to Xbox 1 level of performance. Overall real world performance is something like a 300MHz Pentium 2, only with much, much swankier graphics.</em>&quot;</p>
<p>Note: The price of $25 or $45 excludes a way of powering it (via MicroUSB), a keyboard, a mouse and likely a USB hub. I think you need to provide an SD card too.</p>
 6016: <p>I will step up and answer the Raspberry Pi question too. The RPI in and of itself is not worth using to do virtual currency mining on by itself. However, if you a nice powered USB hub and connect in the ASICs that plug in via the USB ports and download the proper software that can access these devices, then you've got a descent mining rig to speak of.</p>

<p>Note:</p>

<p>Due to the way in which the ASICs are designed, they can only do SHA256D and that alone although, performance per watt is the best way to go. Essentially, all the RPI does is act as the surrogate for all the ASIC slave units and constantly feeds them data and ferries the data hashes back and forth from their source.</p>

<p>You can't use Scrypt with these USB ASICs at all. You'll be stuck using the GETWORK protocol until someone can come up with an ASIC that can do both SHA256D and Scrypt.</p>

<p>One last thing, you may have heard of the Stratum protocol vs. the old GETWORK protocol. This can be used with Scrypt or SHA256D algorithms. Stratum helps you get less stale and has even better network performance than the old protocol.</p>

<p>Hope this clears things up like my message above.</p>
 81238: <p>Great summary here:</p>

<p><a href="https://www.electromaker.io/blog/article/cryptocurrency-mining-on-the-raspberry-pi-60" rel="nofollow noreferrer">https://www.electromaker.io/blog/article/cryptocurrency-mining-on-the-raspberry-pi-60</a></p>

<p>Also includes a step-by-step guide on how to mine crypto currency on the Raspberry pi</p>
 6016: <p>The one thing I should probably answer on is about the difference between OpenGL / OpenGL-ES and OpenCL. Both OpenGL and OpenCl can be used for SHA256d hashing, but OpenCl is used much more frequently. </p>

<p>Where as GL means Graphics Language and CL stands for Compute Language. GL is for graphics and CL is for mathematical and scientific calculations. While your system may have OpenGL support of some sort, it's more than likely doesn't have OpenCL 1 &amp; 2 support for the GP-GPU (VideoCore IV) which would allow you to get okay to medium hash rates. As I see to remember, the VideoCore IV in the Pi doesn't support it in hardware (OpenCL version 1 or 2). </p>

<p>Which means you'd have to rely on those ASIC miners that are connected via the USB port hub or even a dedicated mining rig that is connected via the UTP network connector (RJ-45 jack / Ethernet). </p>

<p>Well, at least we're having a good amount of information / data coming out so the next people that read this will have a good idea on what to do with their RPIs if they want to do any mining.</p>
 1896: <p>It gets less than 200kh/s on the CPU proof here <a href="http://www.youtube.com/watch?v=rrdzam7voOg&amp;list=UUdOgdYMe-hwv2_uUtYlqLDQ&amp;index=1&amp;feature=plcp" rel="noreferrer">http://www.youtube.com/watch?v=rrdzam7voOg&amp;list=UUdOgdYMe-hwv2_uUtYlqLDQ&amp;index=1&amp;feature=plcp</a></p>
 22: <p>The Raspberry Pi uses the VideoCore IV series of GPU, which to my understanding are either a single or dual core GPU running at or around 700 MHz. Since the primary benefit of GPU mining is that you can run many parallel processes on the hundreds of cores typically found in most GPUs, the single-core nature of the VideoCore GPU undoes most of that benefit.</p>

<p>I don't have exact numbers, nor the necessary knowledge to compute an estimate, but I can tell you that the Folding@Home folks <a href="http://www.raspberrypi.org/forum/projects-and-collaboration-general/distributed-computing-like-fh">already discussed this</a> and came to the conclusion that an AMD Phenom II X4 940 was almost 5 times as efficient for their needs as utilizing both the CPU and GPU of the Raspberry Pi. Since the needs of Folding@Home are very similar (but not identical) to Bitcoin's, it's probably not a stretch to say that if CPU mining (admittedly with a fairly nice CPU) is 5x more efficient, the Raspberry Pi doesn't look like a strong contender.</p>

<p>Of course, until we have solid MH/s and actual at-the-wall wattage numbers it's very difficult to say if, at scale, a cluster of $35 Raspberry Pis could compete with other setups on initial price or power cost. Personally, I'd guess not.</p>
 3388: <p>There is a nice wiki page here: <a href="https://en.bitcoin.it/wiki/Mining_hardware_comparison">https://en.bitcoin.it/wiki/Mining_hardware_comparison</a></p>

<p>The raspberry pi is listed by its processor in the arm section: ARM1176JZ(F)-S. It gets 0.2 Mhash/s when clocked at 800 MHz.</p>
