Re: [DCP-o-matic] dcpomatic on Raspberry Pi / Raspian

Am 28.04.2015 um 16:43 schrieb David Nedrow via DCPomatic: Hmm, at first I found it hard to believe a Pi is able to do 1fps (whatever content that is referenced to). However, when I look up the specs for the Pi 2 B, it is actually a QuadCore ARM7 running at 900MHz, and it seems it also has just enough RAM for the render client. I did extensive benchmarking on a large range of machines, with the idea to find sweet spots in the price/performance ratio of different old and new machines. I thought I just found one in the form of second hand Xeon machines/CPUs. What is your base machine/Master feeding the PI ?. Would you try the 'official' benchmark, BigBuck Bunny from here: http://dcpomatic.com/benchmarks/contributing It will only take a few minutes to complete. Please do it one time without the PI 2 B, then delete everything except log and metadata, and do it again with the Pi 2 connected/running. Then post the log. A PI 2 B currently sells just below 40€/US$. That would be 10 fps at, maybe 450€/US$, including power supply (old PC PSU) and network stuff. That isn't much more than possible with traditional hardware, but with a bit of tweaking and reduced prices for larger quantities, it could become interesting. And maybe at some point there will be a slightly cheaper PI 2 B compute module as well... But, again, I still doubt that it will actually do 1-Bunny-fps. The J2k is very dependent on footage, resolution and compression rate, so we really need a stable reference in order to do fair comparisons. We had discussions on network saturation using large numbers of clients on this list a few times. 100MBit/s Ethernet is not enough, and the PI 2 B does max out at 100MBit/s, and who knows how much real world MByte/s that really comes down to. However, as the PI 2 B is only capable of 1fps anyway (potentially), through a 1GBit Switch, a gigabit ethernet master could still feed 15-20 of them without saturating it's own Gigabit connection. Could work up until 15-20fps/PIs. DCP-o-matic saturates gigabit ethernet around 15-20 remote fps. What I currently consider as the sweet spot is 6.7-bunny-fps from a second hand 380-420€ Xeon hexcore 5660 machine that comes with everything it needs to run, except a monitor to set it up. You can double that into 12-bunny-fps if you buy a dual-cpu machine for a few bucks more. I just did that and it comes out at around 550-600€ with dual xeon 5660. That is around 46€ per bunny-fps. Pretty close to the hypothetical PI 2 B render farm already. What bothers the hell out of me is that a 40€ PI 2 B could have the performance of a single xeon core running at 2.8GHz... ;-) Again, I doubt it, but I would be happy to admit I'm in error... BTW - I just tested FinalDCP with the Kakadu-Turbo-J2k-Encoder on this Xeon machine, and it spits out 32fps average on the bunny footage. Wow... Will test it on the dual-xeon machine as soon as possible. What about porting the Kakadu encoder to the PI 2 B? It costs some money, though, but so do the Pies... - Carsten