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I recall that when the Pi2 was released, the build of Raspbian was not optimized for multi core.

Did this ever change? I would like to give a try again to Raspbian (I am using retropie on my pi2 for the moment, but I do no desktop work at all); but only if it has been optimized. I recall that web surfing last year was quite slow, and youtube was also laggy, until the cache was filled.

Most likely these are issues due to the low memory on board, but having a multi core OS would also help.

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The Linux kernel has had parallel processing support for decades, and it has clearly had multicore ARM support for the few months I've been playing with my Pis.

The Linux 4.6 kernel was just released, and it promises better GPU support on the Pis, among other things. I don't know how long it will be before 4.6 is rolled into Raspbian, but it isn't all that hard to build your own kernel.

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  • Yup, I am aware of the support for multi core; but the PI version was not set for multi core (I have to go back and see why; it has been few months now). I can build my own kernel; I was just hoping to get the official raspbian directly...got plenty of projects at the moment; and my last attempt at making a custom version for the PI took me quite some time :) – rataplan May 17 '16 at 8:04
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Your information is wrong.

Linux automatically makes use of all cores.

Any program which uses threads would automatically have threads running on any available core.

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    That's harsh. The original RPi was a single core machine, so the kernel was compiled without Symmetric Multiprocessing support. When the RPi2 was released these older kernels wouldn't activate the additional cores on the RPi2. This wasn't a major drama as the newer kernels were compiled with SMP support and the SD card size was different so it was less trouble for the majority of users to image a new Mini SD card rather than attempt to copy the kernel from an old SD card to a Mini SD card. – vk5tu May 17 '16 at 5:51
  • It's not harsh, it's a fact as far as the questioner goes. I really don't believe the questioner attempted to get a kernel working. Old kernels would not work on the new Pi because all the peripherals were at a different address regardless of any multi-core support. – joan May 17 '16 at 7:49
  • I did not try to get a kernel workingl why should've try when there is an official release of the OS? I did buy the Pi2 few months ago; I did check on the PI groups and I was told that for the time being, the PI2 will be not so fast since the previous build of Raspbian would not make full use of the multicore architecture. I can link you the thread, so you can read where did I get my wrong info. I am aware that Linux is multi core; I use it on my computers via emulation, but I am using the PI version, which I didn't compile nor setup – rataplan May 17 '16 at 8:02
  • A link would be useful. This sounds more like a case of unrealistic expectations. – joan May 17 '16 at 8:10
  • Has been too long for a link; I did a quick search and found only bits and pieces. vk5tu did mention about Symmetric multiprocessing being off on the previous version; I believe that was what others referred in the post that I did mention. Also the applications running on the PI has to support multi core;so beyond the expectations that the OS has to support multi core architecture, there is also the software that has to be converted to take advantage of the 4 cores. Not a case of unrealistic expectations; just facing the realiy that it takes a while to move to a new architecture. – rataplan May 17 '16 at 22:14

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