About the video memory consumption of scene loading

[q976431]

I'm testing a 3080 graphics card
3080 is 10GB of video memory.

When I show all the objects in the scene, or turn on the switch to render hidden objects, and then perform real-time linking, the vantage always fails (I initially thought that the maximum video memory of the 3080 graphics card was exceeded after all the objects in the scene were loaded, so I hidden some scene objects, To ensure that when the video card used for vantage loading is below 10GB, it can be linked in real time normally at this time)

But something happened today that changed my mind and forced me to rethink about video memory.

I use translations and I try to be as clear as possible:

I continued to use the same scene, but this time I turned off all the scene layers, leaving only the building model, and then made a real-time link. After the connection was successful, the vantage showed that only 6GB of video memory was used. Then I opened the scene layers one by one in order, and I was surprised to find out. In the end, vantage actually prompted me to use 17GB of video memory? It actually exceeds the maximum memory of the 3080 graphics card

So please tell me why I can't successfully link in real time after opening all the layers directly, if it is because of the limitation of video memory, then why when I use a small number of models for real-time connection, and then open all the layers, vantage can load it normally, And also allow to exceed the max of 3080 graphics card. This refreshed my initial understanding, because I thought the Vantage's VRAM usage could not exceed the maximum VRAM of the graphics card.

[vladimir.nedev]

When Vantage uses more memory than what's available on the GPU, Windows manages the excess memory by leaving it in CPU memory (the GPU accesses it from there, which is much slower).
We are not quite sure why this results in crashes in some situations and not others, as this happens in the Windows code, which we don't have access to.

Greetings,
Vladimir Nedev

[q976431]

When Vantage uses more memory than what's available on the GPU, Windows manages the excess memory by leaving it in CPU memory (the GPU accesses it from there, which is much slower).
We are not quite sure why this results in crashes in some situations and not others, as this happens in the Windows code, which we don't have access to.

Greetings,
Vladimir Nedev

Through my tests, I found that if the loaded data exceeds the size of the video memory during the initialization of the real-time connection, the vantage will fail to load with a high probability.
However, if you hide a part of the scene according to the method described above, so that the video memory used when the real-time link is initialized is less than the maximum video memory of the graphics card, then after the connection is successful, even if all layers are opened at this time, and the video memory used by vantage exceeds the maximum video memory of the graphics card VRAM, vantage can also run normally. I don't know if you can do some optimization? In order to ensure that the scene data is loaded smoothly when the maximum memory of the graphics card is exceeded, maybe this behavior can be simulated when the real-time connection is initialized to load the data?Asynchronous progressive loading of scene data.

Since I always thought it was not allowed to exceed the maximum VRAM of the graphics card, this discovery allowed me to use the 3080 to render scenes that exceeded the 20GB VRAM requirement. Although like you said, it's probably loading from the CPU somewhere, it's slow, but at least it renders normally with vantage. instead of just popping up an error telling me the load failed.

I don't mind buying a graphics card with more memory, like a 3090,In fact I also have a 3090, but it always has an upper limit. If it is always limited by the maximum memory of the graphics card, I will not be so confident to add a lot of details when making a scene. Because of fear of exceeding the limit of video memory

[vladimir.nedev]

Can you check the debug log to see how much of that memory is textures ?
We are working on optimizing the memory used for textures in Vantage.
We will try to scale them down to the lowest resolution that's still big enough so you don't see a difference (given the current camera view).
This might be enough to fit your scenes in GPU memory.

Greetings,
Vladimir Nedev

[q976431]

Can you check the debug log to see how much of that memory is textures ?
We are working on optimizing the memory used for textures in Vantage.
We will try to scale them down to the lowest resolution that's still big enough so you don't see a difference (given the current camera view).
This might be enough to fit your scenes in GPU memory.

Greetings,
Vladimir Nedev

OK, where can I check this information?

[vladimir.nedev]

Open the debug log from Help -> Open Debug Log and then search for a message that looks like this : "Freed 0.00 bytes of unused textures and uploaded 33.44 Mbytes for 1 newly used texture(s) to GPU memory in 17 ms."
or even better, just copy the whole log and attach it here or send it to my e-mail.

Greetings,
Vladimir Nedev

[q976431]

Open the debug log from Help -> Open Debug Log and then search for a message that looks like this : "Freed 0.00 bytes of unused textures and uploaded 33.44 Mbytes for 1 newly used texture(s) to GPU memory in 17 ms."
or even better, just copy the whole log and attach it here or send it to my e-mail.

Greetings,
Vladimir Nedev

HI.
OK, I'll try. I'll send it to your email later