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I'm not getting the 100x speed
Page 311 says you will get 100 times the speed using VBO's

yeah, well hmmm, a slight exaggeration on my part, it does depend on what target you are using, and also what format the data is, how much there is of it etc.  So while it is actually possible to get 100x the speed, really with the cube demo, it will only get that good on one of the bigger 8-16core high clock GPU systems I have here, the standard Raspberry 3 and lesser models, can't really match that. Though with  proper optimizations you can get pretty close to that.

But even if you can't manage 15000 cubes in 30+fps, you will notice a big boost in speed simply by avoiding doing too many repetitive calls to the GPU and focusing only on doing the minimum number of draw calls.

The cube demo could be a great demo to show you fake instancing, which allows you to draw around 32 cubes with one draw call.. Now..that does give you a massive speed boost as does using indexing, which I don't use anywhere in the book...try checking it out. 

I think I should make it clear in the next edition, that 100x is really for the higher end GPU's and the majority Raspberry users won't get that much
Brian Beuken
Lecturer in Game Programming at Breda University of Applied Sciences.
Author of The Fundamentals of C/C++ Game Programming: Using Target-based Development on SBC's 


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