VEGAS 22/23: Dynamic RAM Preview Causing Runaway VRAM Leak (50 Series)

chell wrote on 10/3/2025, 5:12 PM

i wanted to report an issue i’ve been able to reproduce consistently in both vegas 22 and vegas 23 on an RTX 5080. enabling dynamic ram preview appears to cause a runaway gpu memory leak that eventually destabilizes the entire system.

what happens:

with dynamic ram preview set to 10%:

during playback, dedicated gpu memory usage continuously climbs higher and higher. it only stops climbing when i pause playback.
even after pausing, the gpu memory doesn’t release. it just sits there until i disable dynamic ram preview entirely.
if i let playback continue without pausing, eventually my entire system fails (audio drivers, other applications, everything).

with dynamic ram preview disabled (0%):

playback is stable, with gpu memory sitting in a safe range (8–9.5gb).

Dynamic RAM Preview turned ON:

Dynamic RAM Preview turned OFF:

this isn’t just performance degradation.. it’s kind of a critical stability issue. a runaway memory leak that consumes all available vram until the machine fails makes dynamic ram preview unusable in vegas 22/23 for me, at least.

so! the open question, i guess - is since this behavior shows up for me in both vegas 22 and 23, i’m trying to determine:

is this a vegas issue introduced in 22 onward that affects all or some gpus?
or is this specific to how vegas interacts with the new 50-series architecture?

can the dev team (or anyone else knowledgable) confirm if this is a known issue? if not, could it be investigated? this feels like a serious regression, and i suspect other users may be hitting the same problem without realizing dynamic ram preview is the trigger. I'm really interested to know if this is 50 series specific.

happy to provide videos, logs, or further testing if that would help. My specs are in my signature.

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JulioAZ wrote on 10/28/2025, 3:24 PM

@chell , sorry to bother you again... can you run a new test?!
I noticed that on your video test in preferences, "GPU Acceleration of Video Processing" is set to "Optimal - NVIDIA GeForce 50..." as the active function.
Go to "Preferences → File I/O → Hardware Decoder To Use" and select the dedicated video card. When you change and restart Vegas, notice if the field now only shows the name of the dedicated card without "optimal".
I understand that your case is not a matter of "memory leak", but the problem may be related.

I haven't stopped testing (--"), because I produce large and often tedious projects (lol), so I need software stability or I'll go crazy.

Here I identified a difference between "Optimal" and "Auto" in the two tabs ("Video" and "File I/O"); it seems to really change how Vegas manages the GPU and timeline processes.

I've apparently had good results by changing this simple option. I'll monitor it with new projects, but my instability and memory leak issues have been resolved with this. The VRAM vs. RAM vs. GPU usage ratios seem to be much more stable. 😅
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With the help of ChatGPT, I tried to understand and it reported the following:

"Optimal - XXX"
It activates hybrid routines (decoding one section via the CPU, another via the GPU).
This can cause high and irregular VRAM usage, as Vegas reserves blocks of memory for "pre-buffers" that it may not even use.
This feature comes from recent builds (Vegas 21+) and was designed for systems with both GPU and iGPU active.

"No "Optimal" / No "Auto""
This drastically reduces the use of "phantom" VRAM, because the GPU now works with a fixed buffer (Vegas doesn't reserve additional blocks "just in" case").

Why "Auto" causes the leak and possible instability
When "Hardware Decoder to Use" is set to Auto, Vegas:
- Detects available GPUs and creates parallel instances of the AMF and DXVA2 (AMD) decoders.
- Even if only AMD is in use, it keeps the allocations of both on standby, doubling the VRAM reserve and mirroring parts of it in RAM.

In summary:
"Optimal" + "Auto" activates a hybrid mode that duplicates buffers between the GPU and CPU, which causes memory leaks and instability. By manually forcing the dedicated GPU on both tabs, Vegas uses a more direct and clean pipeline.

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Maybe this isn't the problem, but I thought it was interesting to share and this question about the new pipeline (Vegas 21+) that was implemented makes sense.
I just hope everything gets resolved and we have stability. 👊