Parallella Community

Well, I guess I'm mostly puzzled because I think I have not seen any heat sinks or fans on boards that use the exact same SoC that the Parallella does. I guess the big difference is that Parallella uses the FPGA for HDMI output which those other dev boards probably don't?? Is that generating a lot of heat? Would a headless version run much cooler?

Anyway, I didn't intend sto sound negative, it's just something I genuinely don't understand.

As for the Raspberry Pi, I'm not sure I agree 100% with your comment. The GPU on the Raspi SoC is actually quite powerful, it should actually be in the same ballpark as the 16 core Parallella (the Raspi GPU is quoted with a (yeah, mythical) theoretical peak performance of ca 24 GFLOPS (!!) single precision).

Having said that, the Raspi GPU is not intended for general purpose computing, and that's where the Parallella shines and is innovative, and that's the reason I backed the project and have not regretted it.

The one none-graphics application that AFAIK has been implemented on the Raspberry Pi GPU so far is FFT.

My personal goal is to make an accelerated version of the EInstein@Home "Binary Pulsar Search" app that needs a length 3*2^22 real-to-complex FFT for both the Raspi and the Parallella.

At the moment I am quite sure the Raspi GPU will beat the 16 core Epiphany. If anyone thinks he/she can do a 3*2^22 real-to-complex FFT (single precision) faster on the Parallella than the fatest version using the RaspiPi's GPU, please let me know. I might be willing to make a formal bet out of it, with (say) a crate of beer as the prize .

Cheers
HBE

I'll take your bet regarding the FFT. That's a no brainer:-) Let's set a deadline of September 15th..that way I will have something to drink by the time my birthday comes around.
Andreas

w000000000t!!!!!!

Great, so it's a deal!! September 15th is fine for me.


It's a nice incentive for me to start work on the Raspi GPU FFT

HB

Cool! If you improve the FFT for the raspi that would be a great service, since there are about 2M of those in the field. Imagine the power if they were all connected! Can you provide a pointer to the FFT API and functional call that needs to be implemented (+range of N).
Andreas

The bet is that with a Raspi you can outperform the Parallella on specific FFTs : N=3*2^22, real-to-complex, single precision. In-place or out-of-place, whatever is fastest on each platform.

I'm open to allow overclocking within reasonable limits (say with air cooling, not liquid helium or some such )

Parallella may use the ARM cores, FPGA and Epiphany 16. Raspi can use the ARM core and the GPU.

FFT is not the best suited algorithm for GPUs or many-core-accelerators like the Epiphany, as the ratio of computation instructions to memory transfers is relatively low. [we don't do things because they are easy, right? ]. OTOH FFT is one of the most important numerical algorithms ever, so implementing FFT on a new piece of hardware is the second thing you do, right after "Hello world".

Cheers
HB