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From what I understand, currently almost all GPU architectures* are some variant of VLIW, with some "tricks" to get the processing cores to work with high effic

From what I understand, currently almost all GPU architectures* are some variant of VLIW, with some "tricks" to get the processing cores to work with high efficiency (that is, use all the cores available for a given task). A few years ago Michael Abrash wrote a wonderful article[1] on the Larrabee project, by Intel, which ultimately resulted not on a graphics card, as he intended, but on a "processing card"[2][3]. Of course, anything you read by Abrash in that topic will be more than interesting. * Intel HD GPUs may or may no be VLIW, I have never been able to find detailed specs of their architecture. [1] http://www.drdobbs.com/parallel/a-first-look-at-the-larrabee-new-instruc/216402188 http://www.drdobbs.com/parallel/a-first-look-at-the-larrabee... [2] http://en.wikipedia.org/wiki/Larrabee_%28microarchitecture%29 http://en.wikipedia.org/wiki/Larrabee_%28microarchitecture%2... [3] http://en.wikipedia.org/wiki/Xeon_Phi http://en.wikipedia.org/wiki/Xeon_Phi

brigade 12y ago
I was about to say "not really, the only current VLIW GPUs are ARM's Mali" but after reading more of the documentation I guess you're kind of right... Maxwell requires explicitly encoding when to dual-issue instructions, which is basically the defining feature of VLIW. That said, VLIW is designed/intended for architectures that are highly superscalar within a single thread of execution. GPUs have eschewed that model in favor of simply executing more threads. So a better (simplistic) model of viewing modern GPUs is "AVX-1024 with massive hyperthreading"
- dr_zoidberg 12y ago
  And with that cue, you gave me room to place another article by Michael Abrash on the Larrabee architecture (which is pretty much what you thought as a model): http://www.drdobbs.com/parallel/rasterization-on-larrabee/217200602 http://www.drdobbs.com/parallel/rasterization-on-larrabee/21... This thread has been wonderful for reading all this amazing things about different architectures, hardware and software, but I should get working. I leave with a lot more to read the following weekend! :)

brigade 12y ago

I was about to say "not really, the only current VLIW GPUs are ARM's Mali" but after reading more of the documentation I guess you're kind of right... Maxwell requires explicitly encoding when to dual-issue instructions, which is basically the defining feature of VLIW. That said, VLIW is designed/intended for architectures that are highly superscalar within a single thread of execution. GPUs have eschewed that model in favor of simply executing more threads. So a better (simplistic) model of viewing modern GPUs is "AVX-1024 with massive hyperthreading"

dr_zoidberg 12y ago
And with that cue, you gave me room to place another article by Michael Abrash on the Larrabee architecture (which is pretty much what you thought as a model): http://www.drdobbs.com/parallel/rasterization-on-larrabee/217200602 http://www.drdobbs.com/parallel/rasterization-on-larrabee/21... This thread has been wonderful for reading all this amazing things about different architectures, hardware and software, but I should get working. I leave with a lot more to read the following weekend! :)