The title says it all.
What are swap buffers ingame and why would this card:
[url=http://laptopmedia.com/video-card/nvidia-geforce-940mx-2gb-gddr5/)]Nvidia geforce 940mx[/url]
perform very poorly with maxed out buffers compared to this one:
[url=https://www.mindfactory.de/product_info.php/2GB-Gigabyte-Radeon-R7-260X-OC-Aktiv-PCIe-3-0-x16--Retail-_936720.html]AMD Radeon R7 260x[/url]
which has the swap buffers barly even showing.
Some pictures:
940mx:
[t]http://i.imgur.com/q25g2YG.jpg[/t]
R7 260x:
[t]http://i.imgur.com/gx3jToN.jpg[/t]
further reference:
[url]https://facepunch.com/showthread.php?t=1556407[/url]
[editline]a[/editline]
Another thing could be that my laptop is somehow always forcing Cpu integrated graphics as the performance oes not change at all after deliberately switching to integrated graphics in the NVIDIA Control panel. Implying that setting back to NVIDIA graphics doesnt actually do that but rather still use the integrated graphics.
Swap buffers are buffers for Swap Chains.
[url]https://msdn.microsoft.com/en-us/library/windows/desktop/bb206356(v=vs.85).aspx[/url]
The buffer is drawn, then swapped to be displayed to the user. The now-swapped buffer can now be shown to the user, without being wiped out by a new frame being drawn, since the new frame is being drawn to another buffer.
Swapping should be really cheap since all you're really doing is changing a pointer, last I checked.
But the 940MX is a notebook GPU, I'm guessing it has no dedicated memory of its own. I'm guessing the buffer is being copied at some point, which would be slow as hell since it's happening in system memory instead of the GPUs own VRAM, since the GPU has none.
I have a laptop with an 840M. It's 2GB dedicated, isn't it.
It's always really confusing to me. The specs always say "up to" 2GB DDR3 VRAM. It makes me think that it's not dedicated... but then, they always add (Dedicated). What the heck?
From looking at my Windows installation, it claims to be able to page all 8GB (7.9GB, but still).
I guess the only way to check is to actually whip up some OpenGL program and see if it will dip into my RAM at the moment GLTexImage is called (that's exactly when it goes from buffer VRAM).
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