Hi all,
I have a simple motion blur demo (from opengl superbibile 5th ed.). I can toggle PBO/mem version in the demo. I get around 170 fps without PBO and with PBO I get around 85 fps. Why is there such a big difference in performance. And the pbo is setup using GL_DYNAMIC_DRAW, I tried GL_DYNAMIC_READ and GL_DYNAMIC_COPY and they all give approx. the same fps.
Is this expected that PBO will perform poor if the machine is fast?
Thanks,
Mobeen
Are you talking about Chapter08/pix_buffs/pix_buffs.cpp?
To answer the question you’re indirectly asking, using PBOs doesn’t guarentee you a performance increase. You have to use them intelligently. The main utilities being to parallelize CPU and GPU work, and to leave data on the GPU so you don’t have to send it again. It may be the use case in that example isn’t the best.
Yes, its the pix_buffs example. The timings reported in the book conflicted completely to the timing I got so I was confused why should I bother using PBO when it is so slow. The frame rate is nearly half (95 compared to 175 without PBO). Anyways thanks for the insight.
My platform details;
NVIDIA Quadro FX 5800
Driver version 259.81 (latest driver released todate)
Dell Precision T7500 with Intel Xeon E5507 2.27GHz
OS: Windows 7 64 bit