Re: [LAD] FLTK vs GTKmm

On Mon, 2009-08-10 at 21:43 -0400, David Robillard wrote: Most certainly. The driver is very predictably processing each batch to completion, so if there are no X-events queued up, then you 'own' the GPU. Anything OpenGL and you're fried though - not even GLX gears in a small window, at least not with buffer sizes around 1ms. Increasing the buffers/jitter to around 5ms does away with that problem though, so that glxgears can run in 256×256 (along with the previous smallish video stream and Atari ST emulation [running a MIDI-sequencer]), oh and apparently also GLX in full screen. Increased buffers also does away with artifacts coming from certain Firefox redraws (where this site http://carlbildt.wordpress.com/ mysteriously is affected while this site http://arstechnica.com/ is not.) This is with the tiniest most out-fashioned device almost available which do not have newer features like overlapping processing/transfers for alternating streams. The motherboard chipset on say the ION-platform would have near twice the processing power, and you could then also do away with any transfers and just read from normal memory, leaving the Intel companion chip to do interrupt processing and nothing much else. If anybody would be interested in doing a concerted effort of optimizing PCIe transfers in jackd for cross platform CUDA audio processing, then - well - I am here, as well as over at the CUDA forums. I imagine that, as seen from say qjackctl, this should just look the same as any other hardware you may have - like a sound-card - with 32 or perhaps 64 channels in/out. What happens at the other side, what those channels connects to, would be up to the user/programmer. Running several kernels in succession, the one piped into the other has very little overhead, although it might be a better strategy to do different parts of the scene in parallel on neighboring processors. Very few people who does not work at TU-Berlin actually needs more than 640 channel strips ;) The reward would be having huge arrays of GHz processors for about one dollar a pop! Memory bandwidth in the triple digit range to go with that. Or like me, just enjoy the bliss of silent computing on something a little less ambitious. /j 8<-------------------------------------- update: The performance increase for GTK pixmaps I experienced earlier came because the X conf defaulted to 8bit after the Nvidia card was disabled ... darned! I'll have to redo that experiment with the Intel driver again some other day, and for now just remember that switching to 8bit might allow for more 'blinkenlights' while still processing near RT on the GPU.