UE 5.1-5.2 Render Target Memory Leak

General Feedback & Requests
1

Hello, since 5.1 I have a big problem with the Render Target large, there is a big memory leak on the GPU side of a factor of at least 4, which poses a lot of concern on the possible tools that need large render target.
I did the test from 4.25 to 5.2, and I found out that the problems are from 5.1, for example I go up to more than 20GB of Vram for 3 RT RGBA 16f 8K, which does not happen at all on the older version.

I created a test project with 3 RT RGBA 16f 8K, at the time of the creation have well the good rate of memory used, but from the moment or I must draw on the Vram rises very high, without going down, I think that it is a leak memory.
I use a RTX 2070 8GB (so there is a lot of memory share that is used, personally it makes me a crash).
I have tested several people with different configurations and even GPUs of different brands, the finding is the same (AMD RX 7900 xtx, RTX 4080, RTX 3070 , RTX 2070).
I put the link to the project below, and I also need a report in issue, but I have no news, and it is very blocking for many things especially for advanced tools.

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Conf:

i7 7800x
32go Ram @ 2400mhz
RTX 2070 8go
Win 10 LTSC 21h2

2

Hi CyberAlien, I just tested your repro project and I can also ensure that there is a memory leak going on here.

So I just runned the editor utility widget (right click on it and “run”) and that’s what I got on 5.1.1 (custom source build), no problem on 5.0 tho (launcher build)
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My config:
CPU: i7 6700k
GPU: RTX 2070 (8GB)
RAM: 16GB

Nvidia driver ver: 531.41

3

Yeah, I also seem to be running into this issue. I have 2 render targets created. When created they don’t take memory but as soon as the screen changes and they are updated, I see the memory increases but never goes back down.

4

Same here on 5.2.0.Can confirm i have VRam leak related to calling resize RT on viewport window size change.