On 14 September 2013 12:14, Alex Fowler <alex.murat...@gmail.com> wrote:
> Timothy, thanks,for giving a thorough answer to my questions, I appreciate > this! As far as I understood, you did some work for Clojure team, and you > have the necessary knowledge to express a knowing opinion on what are the > implications of the matter. > James, for some numbers on OpenGL penalties, please refer to message #6 in > thread (my initial answer for Timothy). You can also google on it, I am > sure, you will find more information, or, why not, simply call NVIDIA or > ATI support lines, and ask them. A perfectly valid question for them to > consult you on :) As for more Java-friendly answers, you might also be > interested in asking on LWJGL or JOGL forums. Personally I work with OpenGL > for quite a long time already. Even when we were on C/C++ we never used > doubles. Then we went Java, and there too, doubles are nowhere. One of the > cornerstone computational workhorses of LWJGL, for example, the class > Vertex3f, has no double version. And that is for a reason, not because Java > bindings are bad and we must go C-plus-plusing now. Probably, after 10 > years we will have only doubles and longs on GPUs... do you believe in it? > Why we need them there at all? > But presumably you've done some benchmarks that show a loss in performance? Otherwise I don't understand why you'd be arguing so passionately. I did some some benchmarks myself, but any performance loss was below the noise level of my machine. In theory, if HotSpot is doing its job, then the conversion from a double to the float is compiled down to a single machine instruction. On the i7 architecture at least, the reciprocal throughput for converting a float from double to single precision is one clock cycle. If you're pushing data to the GPU, aren't your primary performance bottlenecks going to be the latency and bandwidth of the link? I'm having difficulty seeing how a double-to-float conversion would be an significant issue. - James -- -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
