Blender 2.74 - Cycles.

I am working on some apparently demanding scenes - and am trying to do GPU cycles rendering. I want to be intelligent in my scene but at this moment I'm using 1.7gb ram and it's only going to get more involved.

Is there anyway to get better insight into GPU RAM usage in cycles without turning things on and off (objects, textures, etc) and trying to discover the difference in usage? Can I just get a report or something of what is allocating how much? Textures, BVHs, etc.

  • $\begingroup$ In windows you can try msi afterburner. It will graph the use of the cpu, vRAM (along with temperature and other things) $\endgroup$
    – user1853
    Nov 8, 2016 at 19:57
  • 2
    $\begingroup$ @cegaton please, read question carefully, this isn't what is needed $\endgroup$
    – Crantisz
    Nov 8, 2016 at 20:14
  • 1
    $\begingroup$ There is a GSoC project for this: wiki.blender.org/index.php/User:DingTo/GSoC_2016/Proposal $\endgroup$ Nov 9, 2016 at 17:13
  • $\begingroup$ @Jerryno it can be great, but it hadn't done $\endgroup$
    – Crantisz
    Nov 9, 2016 at 17:55
  • $\begingroup$ @Crantisz yep, the feature we are talking about is only 20% done.. $\endgroup$ Nov 9, 2016 at 20:25

2 Answers 2


I'm not a math guy but it remember me a question I've posted on a French forum some years ago.
From what I've understood textures are uncompress in memory, so in order to have the number of Bytes used:

1 RGB texture: width x high (in pixels) x 3
1 RGBA texture: width x high (in pixels) x 4
1 HDR : width x high (in pixels) x 12
The rendered image : width x high (in pixels) x 4

each vertex = 24 Bytes
each object +/- 200 Bytes

200/300MB for Blender display
12% to 20% of total memory for cuda... surely this will vary a lot between cards.

It's certainly theorical and incomplete but it can give you an idea, plus there are certainly peoples with better knowledge than me who can correct/complete or make a script.

Refs (sorry it's in French):

  • $\begingroup$ It's a useful comment, maybe it's not very hard to make a script to calculate it, but what about BVH cache? How do measure it? $\endgroup$
    – Crantisz
    Nov 12, 2016 at 18:04
  • $\begingroup$ Sorry I don't know more, but for what I remember, I've made the math by hand for one of my scene, and it was close to the total of ram used by the graphic card. Try it to see if it's working, Cycles has had a lot of improvement since then, but if the result is close enough to have a good estimation, someone might be interested to make a script. $\endgroup$
    – Mareck
    Nov 13, 2016 at 0:35

You can run blender from the terminal with blender --debug-cycles I know this gives some information but may not give you everything. In order for this to give you the best results use blender 2.78a.

  • $\begingroup$ It looks cool, but not exactly what is needed. For example, textures: it shows how match size it use, but doesn't show texture name. So I also have to guess what is texture is $\endgroup$
    – Crantisz
    Nov 9, 2016 at 6:29
  • $\begingroup$ I do not think it is possible at the moment then. $\endgroup$
    – Aaron
    Nov 9, 2016 at 18:32

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