Multi GPU and missing Vram

[indi_80]

Hi

A have 3 x gtx 780 Ti 3gb
I know that one card need reserve memory for screen.
But even if switch off in octane setting from render this one I'm using for system the other ones in Octane LV still lost 0.5gb vram used/free/total >>> used+free do not equal total 3gb (i use c4d plugin - but check also in stand alone)
Should i disable GPUs somewhere in Windows settings?
I try to search forum bu can't find nothing about this

[3d_sploshnoff]

I have the same problem... 2X Titan12gb. Used 6gb.

[zoppo]

Same here.

1x GTX 970 for the monitors, disabled in Octane (C4D plugin)

2x GTX 980ti > 5.6 - 5.7GB of 6GB available

[grimm]

I'm not sure, but I would assume that some of this is taken by the Octane kernel and the memory that it needs to operate. This can also be taken up by the final output image depending on it's size. Although I think in V3 a lot of this memory usage has been moved back to main system memory?

[tomsaunders]

I have the same problem... 2X Titan12gb. Used 6gb.

Hello,

Same here. 2 x Titan X12GB and it says only 12GB available.

Did you manage to fix this? I should surely have access to 24GB?

Cheers,
Tom

Screen Shot 2017-01-24 at 09.39.08.png (41.01 KiB) Viewed 4161 times

[Lewis]

Did you manage to fix this? I should surely have access to 24GB?

Screen Shot 2017-01-24 at 09.39.08.png

No you shouldn't have 24GB, RAM is not combined, Each GPU needs to get same data uploaded to it since they work in parallel so you can have only RAM as much as your lowest GPU has. So as an example in theoretical case that you mix 3*TitanX + 1 780 Ti you will have only 3GB available unless you disable 780Ti.

Also missing .5-2.2 GB is due Windows memory reservation which is far worse in win10 and 8.1 than it was in win7 and win8.
On 6GB GPU on win10 you will "miss" about 1GB VRAM, TitanX will miss 2.1-2.2GB VRAM on win10 and 1.1GB on win7, etc. etc...

you can check this topic for more info:
viewtopic.php?f=12&t=51992

[BorisGoreta]

Windows 10 is shit !