CODEWITHSUNDEEP
c++performanceopenglubuntu
Dici
Dici

Reputation: 25950

OpenGL low performances on my computer

We began learning OpenGL at school and, in particular, implemented a .obj mesh loader. When I run my code at school with quite heavy meshes (4M up to 17M faces), I have to wait a few seconds for the mesh to be loaded but once it is done, I can rotate and move the scene with a perfect fluidity.

I compiled the same code at home, and I have very low performances when moving in a scene where heavy meshes are displayed.

I'm using the 3.0 Mesa 10.1.3 version of OpenGL (this is the output of cout << glGetString(GL_version) << endl) and compiling with g++-4.9. I don't remember the version numbers of my school but I'll update my message as soon as possible if needed. Finally, I'm on Ubuntu 14.04 my graphic card is a Nvidia Geforce 605, my CPU is an Intel(R) Core(TM) i5-2320 CPU @ 3.00GHz, and I have 8Go RAM.

If you have any idea to help me to understand (and fix it) why it is running so slowly on a quite good computer (certainly not a racehorse but good enough for that), please tell me. Thanks in advance !

Upvotes: 0

Views: 173

Answers (1)

datenwolf
datenwolf

Reputation: 162164

TL;DR: You're using the wrong driver. Install the proprietary, closed source binary drivers from NVidia and you'll get very good performance. Also with a GeForce 605 you should get some OpenGL-4.x support.

I'm using the 3.0 Mesa 10.1.3 version of OpenGL (…) my graphic card is a Nvidia Geforce 605

That's your problem right there. The open source "Noveau" drivers for NVidia GPUs that are part of Mesa are a very long way from offering any kind of reasonable HW acceleration support. This is because NVidia doesn't publish openly available documentation on their GPU's low level programming.

So at the moment the only option for getting HW accelerated OpenGL on your GPU is to install NVidia's proprietary drivers. They are available on NVidia's website; however since your GPU isn't "bleeding edge" right now I recommend you use those installable through the package manager; you'll have to add a "nonfree" package source repository though.

This is in stark contrast to the AMD GPUs which have full documentation coverage, openly accessible. Because of that the Mesa "radeon" drivers are quite mature; full OpenGL-3.3 core support, with performance good enough for most applications, in some applications even outperforming AMD's proprietary drivers. OpenGL-4 support is work in progress for Mesa at a whole and last time I checked the "radeon" drivers' development was actually moving at a faster pace than the Mesa OpenGL state tracker itself.

Upvotes: 2

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