RAM usage problem whilst editing

I have a problem with my RAM and CPU/GPU while editing. My GPU is GTX1080 (8GB) and it only fills up to 3,5GB max. Usually I have around 4 or 5 GB of memory shared (from the RAM).

I have both the sliders in Resolve on the max for maximal usage of the RAM but I only have 16 out of 32GB RAM used. Is there any limitation in the software (Windows 10) that tells Resolve to actually not use more than some amount? In device manager there's maximum of 8GB used.

So to sum it up, my GPU memory doesn't fill up and my RAM doesn't fill up - leading to CPU 100% usage spikes for around 5 seconds after any editing action like moving a single clip (I only have like 35 of them on my timeline). I have a studio version of Resolve 18 and an i7-10700kf.

How can I manage to let all of the RAM and also the rest of the GPU memory to be used by Resolve so I don't have to deal with terrible lags making the software basically unusable for bigger projects? I'll get back to you ASAP if you have any further questions about information I forgot to mention.
Thank you!!

RAM and VRAM not being filled is a good thing. Bad things happen when they are.

That CPU spike is likely unrelated.

You didn't specify any actual interference with work, so if that's true, I'd not worry about it.

What do you mean I didn't specify any interference with work? The program is basically unusable for me. Everytime I move a single clip the CPU spikes to 100% for around 5 seconds leaving the computer lagged almost completely. How do you not worry about that?

Everybody I've seen on youtube dealing with other issues (most of them have the opposite problem of Resolve taking up 95% of RAM leaving system unresponsive most of the time) - they have VRAM filled to about 85-90% and after that the Shared Memory starts to kick in. They don't experience the same problem of CPU spikes after a single clip operation (simple move on the timeline).

Does anybody know what can I do to help my machine work normally like the rest of the world? What am I missing? I tried changing nearly EVERY possible setting that could have any impact in Resolve, no effect. If you saw it with your eyes, you would refuse to work with the timeline after 5 minutes of trying.

[Peter Chamberlain]

Forget about the ram. Please start by listing in detail the hardware, as per the faqs.

and then details on the source media codec, frame rate, res, etc.
then timeline frame rate, res.

my wild guess is your codec is heavily compressed, like h.264, and you are on the free version so no able to enjoy the use of the GPU to decode the h.264 its likely the CPU is busy trying to decode the clips. And when you move a clip or trim that causes the whole timeline to move, all those clips need decoding to display.... but we will know more when you provide details.

Okay I'll start with the details since this seems to be something rather tricky to solve. First of all I have the studio version (it's in the first post) because I hoped the issue would go away - it did not.

CPU 10700kf, 32GB RAM, GTX1080 GPU, 1TB SSD (files at work on it, Resolve as well of course).

Source media: Sony a7SIII 4k 50FPS XAVC-S (all clips in timeline).
Resolve timeline: 25FPS, 1920x1080 resolution for better workflow.

Proxy Handling - Prefer Proxies
Timeline Proxy Resolution - Half
Render Cache - Smart
Proxy Media and Render Cache Format - DNxHR SQ
Memory Configuration both sliders to the right (24GB and 18GB - from 31,9GB)
GPU Processing mode tried both CUDA and OpenCL - no change (yes GTX1080 is selected)
Media Storage is the default Root on the SSD, Direct I/O

Decode Options everything checked there except easy DCP decoder (tried with that but no change again)
Basically every (almost every) other setting has been untouched.

Now for a better description of what's happening - I personally think it has to be RAM or VRAM software limitation (I have no problems using all the capacity when using other demanding software) because: when not touching anything in a project (about 150clips, 2 minutes long, no color grading applied)

Resolve takes up 7GB of RAM and about 1,4GB of VRAM. Moving clips from one place to another leads Resolve to use PRECISELY 8GB of RAM which follows by 100% CPU usage (I'm no IT expert but from my experience this happens when you run out of RAM for example with an older machine with 4GB of RAM trying to run let's say Photoshop, something like filter gallery, Camera Raw or something of a similar demanding sort).

The Resolve RAM usage NEVER goes above 8GB, always just 100% CPU spike for +-5 seconds - after that RAM usage falls back to about 7GB and all is good until next operation (yes it's driving me absolutely nuts). In these moments the GPU VRAM goes to about 3GB and after that it falls back to +-1,4GB (capacity is 8GB, never goes above 3GB).

Do you have any clue what am I missing? Any other settings that needs to be changed? Nobody seems to solve this issue on the whole internet (only the other way around which is high RAM usage...)
Thank you!

[Peter Chamberlain]

You have 50fps clips, in XAVC so need extensive decoding, and then drop every second frame to fit into a 25fps timeline, or run the clips at half speed.

In a new project, try a 50fps timeline and see what happens.

Question for Peter. Along with the change to a 50fps timeline, would transcoding the footage to a different format be helpful for his issue? Understanding the pros and cons of different formats is a weakness of mine.

Your source media is very demanding and for fluid operation you'll need DR Studio, an Intel iGPU of one of the latest two generations, or Apple silicon.
If one of these conditions is not met, converting into DnxHR or Cineform will help, but at the expense of needing a lot more storage space.
And then, it'll make it easier for your machine if you need to convert between 50 fps and 25 fps or vice versa to set the conversion to Nearest instead of Optical Flow (see project settings for re-timing).

Just tried a new 50fps timeline (nobody I know with the a7SIII does this, almost always 24fps), it's still the same. Issue is still there.
I have the Studio version, not free. GPU is being used about 5-10% when playing the timeline, VRAM limited to about 1,4GB. RAM sort of limited to 8GB, never goes beyond, thus CPU 100% until operation is done. Does not want to go higher even though I have plenty memory left (18 more GB).
Looked up the re-timing setting - set to Nearest all the time, no Optical Flow.
I get it is demanding but literally NOBODY else seems to have this issue (noone I know has an Intel iGPU nor Apple). Even older GPUs like GTX950Ti and similar and they have smooth playback (at least to some degree) but most importantly they don't experience ANY lags due to CPU 100%. No media convertion neither.
Any other thoughts? Is my computer haunted?
Thank you for help!

Switch your camera to one of the H.264 versions and you should be fine.

I am using the XAVC-S codec which is h264.

Then there should be no terrible lags.

Umm... it sounds a bit like people are telling the original poster (OP) he's not seeing what he's seeing.
That would clearly be frustrating for the OP.

OP: would you do a screen recording of what's happening, put it on youtube, and post a link here? There's nothing quite like experiencing what's happening to open people's hearts.

@Peter: you said above that without Studio the OP won't get hardware GPU acceleration of H.264.
This thread seems to disagree with that: viewtopic.php?f=21&t=166461
What's the real scoop?

Thanks!

XAVC-S is a long gop consumer version of Sony's professional XAVC codec. It is not ideal for post and is very demanding, even in HD @ 24/25p. You have 4K clips at 50p, notwithstanding you are working in a 1080 timeline and proxies. Since your clips seem, from what you say to be short, I would transcode them to a post friendly codec, such as DNxHR or Prores.

Extremely likely that that would solve your problem.


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Well, he has Studio, so the codec should get accelerated.
But conversion is the way to go if it stutters or lags.

Well, he has Studio, so the codec should get accelerated.
But conversion is the way to go if it stutters or lags.

Uli, until recently, in Avid you had to use a 3rd party plugin, from Nablet, to even play this codec and even on dual Xeon HPs, with 128gb ram +, it could stutter and if you dissolved or anything it was essential to render the motion adaptor. This was at HD 25p! A while back I was editing a documentary on the client's iMac, with 32GB ram and had a similar devil of a time with this codec. As I understand and I have Studio too, proxies etc. are more cache than real transcoding and so ram and cpu gets used a lot in that process. I can see that with the difference between 4.6K Braw and 4K XAVC proper, where the Braw is much easier to work with, without proxies and at full rez, as opposed to the Sony codec.

@Peter: you said above that without Studio the OP won't get hardware GPU acceleration of H.264.
This thread seems to disagree with that: viewtopic.php?f=21&t=166461
What's the real scoop?

Thanks!

The devil is in the details. If he's shooting AVC/H.264 footage with 4:2:2 subsampling neither the GTX 1080 GPU nor the 10th gen Intel CPU will have the required hardware decoder even if Resolve supports it. So it will be decoding using software only.

Dang. Sounds like we need an indicator for whether HW acceleration is enabled (ie you have studio) and whether it’s being used on any given clip. And it’d sure be nice - if acceleration were enabled but not in use - for it to tell you why.

All this logic has to be in the program already. It’s just not plumbed up to any ui.


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That would certainly limit the endless amount of forum threads about codec hardware acceleration.

Umm... it sounds a bit like people are telling the original poster (OP) he's not seeing what he's seeing.
That would clearly be frustrating for the OP.

OP: would you do a screen recording of what's happening, put it on youtube, and post a link here? There's nothing quite like experiencing what's happening to open people's hearts.

@Peter: you said above that without Studio the OP won't get hardware GPU acceleration of H.264.
This thread seems to disagree with that: viewtopic.php?f=21&t=166461
What's the real scoop?

Thanks!

I will get to that after I return from my travels (2 weeks).
Thank you all!