First thing you should do is go to preferences/FIle IO, and click on Legacy AVC. This will use the same CPU decoder as VP13 and turn off GPU decoding. You may exclaim:

'How on earth did they manage to increase timeline lag on a product with 10years potential to refine performance plus added GPU decoding?"

That's a good question, I'd love to know too. At 1440P AVC and below or maybe even 4K AVC (depending on encoding) with your CPU you will likely have less lag over edit points/transitions with GPU decoding OFF. Possibly you have a real problem that can be fixed, but as you describe it, it sounds reasonably normal depending on what you're trying to play. Tested some 2160x3840 AVC phone footage just then, with legacy AVC turned on it's good, but unticked lags at basic cross fade transitions

If your 1440P is from a screen recorder there may be settings you can alter with it's recording settings to make it play better with Vegas's GPU decoder

Enable Preferences – FileIO – Legacy AVC Decoding to see if this help.

Awesome, this helped a lot. Thanks!

'How on earth did they manage to increase timeline lag on a product with 10years potential to refine performance plus added GPU decoding?"

I expect a much faster response when using GPU decoding in a product of this class, but well... seems like the GPU decoding is still beta or something :-(

@TSP Hi, I can't go into details but I sympathise, I find Vegas doesn't perform quite as well as i would expect or hope given my PC specs which aren't a huge amount different to yours.

The media you're using can make quite a difference, I've taken to converting my media to ProRes which plays 100% better.

If you're not aware of it there's an App called MediaInfo, download it, it's free & a fast download with no added adverts or any of that rubbish. https://mediaarea.net/en/MediaInfo
After downloading, right click on the media file in your Windows folder, open MediaInfo, choose Text from the options at the top, Copy & paste the information in a new comment on here 👍

Like this

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PS. My PC specs are in my Signature, can you click your icon at the top of this page - My Profile & fill in your Signature with the full name of your CPU, GPU & amount of RAM, also inc the Windows & Vegas version, this will then show at the bottom of your comments,

I recently upgraded from "Sony Movie Studio 13" to "Vegas Pro Edit 21 (Build 108)" and right away imported my current project (1440p@60 with a timeline of 2 minutes and 3 video tracks and one audio track, all footage MP4/H264 - nothing extraordinary).

The first thing i did was using stock settings and previewed the project and even after the first seconds, it starts to lag and skip a lot of frames - especially when it renders transitions. With sony movie studio i almost never had a skipped frame, except for 3D transitions, which i dont use for that reason.

 

How can i fix this?

 

I am new to vegas, but i dont think my hardware is the problem here because my system is very fast and was especially built for content creation:

- MB: ASUS TUF Gaming X670-E-PLUS

- CPU: AMD Ryzen 7950X (16 Cores, 32 Threads, up to 5.5 GHz)

- Cooler: Artic Liquid Freezer II 360mm AIO

- RAM: 64 GB DDR-5 6000 MT/s running in EXPO mode

- GPU: ASUS ROG STRIX RTX 3090 with 24 GB

- SSD: 2x Samsung SSD 980 Pro

- Audio: Creative Soundblaster AE-7

- OS: Windows 10 with latest updates and drivers

 

If this will help, i can upload a video that shows everything.

 

You might try a benchmark to make sure everything is running normally for a computer of this spec. Try filling out the VP 20 one in my signature.

Can you share MediaInfo for the specific media? https://www.vegascreativesoftware.info/us/forum/faq-how-to-post-mediainfo-and-vegas-pro-file-properties--104561/

While legacyAVC decoding gets you back to where you were with the old software it isn't necessary these days for the most part. As mentioned above, better capture settings can help, or batch re-encoding known troublesome footage into a format that's more easily decoded in VEGAS (ProRes or even vanilla constant framerate short GOP h264 using ShutterEncoder).

'How on earth did they manage to increase timeline lag on a product with 10years potential to refine performance plus added GPU decoding?"

I expect a much faster response when using GPU decoding in a product of this class, but well... seems like the GPU decoding is still beta or something :-(

The GPU decoder lagged 6 years ago when introduced, it lags today.

At some point you just gotta admit to yourself that they're not fixing it, and to try work arounds where available. The really big problem is HEVC, it only became established as a distributable format due to GPU decoders, much like AV1 in the future. A $60 android can decode HEVC fine, but not Vegas Pro for many codecs, resolutions and frame rates without lagging. It's a master class in losing customers.

I did some testing for the recent days and with legacy AVC decoding, editing works smoothly - even with 1440p@120 Hz footage.

But rendering was extremely demanding on my CPU, resulting in instantly 95° celcius CPU temps while rendering. Even though, its normal behavior on ryzen 7000 series CPU, for me this is too hot. So i locked down my CPU to a PPT of 105W and Thermal-Limit of 75° celsius - that resulted in a lost of ~10% performance, but the CPU is now much cooler, 67° celcius and ~97W power draw. I am aware that with undervolting, i could get almost the same stock performance - but i lost in the silicon lottery and most of my CPU cores dont like negative voltage offsets :-(

But in vegas itself, i dont see any difference - so i leave it like that for now.

Also i switched from Main Concept encoder to the NV encoder instead and got an decrease of 30% of rendering time.

Rendering should be about the encoder, not the decoder. Mainconcept will load the CPU at 100%, so get your fans ready.

NVENC should displace most of the load to the GPU from the CPU. Usually you would get more than a 30% improvement in render time- there must be something in addition keeping the CPU busy (Fx?)

I try to keep my 13th gen Intel CPU under 180W as the air cooling system can't handle much above that without getting into the upper 90Cs.

I did some testing for the recent days and with legacy AVC decoding, editing works smoothly - even with 1440p@120 Hz footage.

But rendering was extremely demanding on my CPU, resulting in instantly 95° celcius CPU temps while rendering.

Potentially you could turn GPU decoding on again by deactivating legacy AVC when you go to encode. Very fiddly but would make sense the longer your project is. Keep the stress of the CPU especially when hardware encoding.

Potentially you could turn GPU decoding on again by deactivating legacy AVC when you go to encode. Very fiddly but would make sense the longer your project is. Keep the stress of the CPU especially when hardware encoding.

I tried that, but deactivated legacy AVC was slower than activated one.

That's interesting, maybe because your CPU has such high IPC, with my 5900x encoding to 1440P Nvenc from 1440P media I get 100fps with GPU decoder, 105fps using legacy AVC, similar enough not to worry. I tried with resolve too 280fps with both decoder on and off.

EDIT: Actually you should check if your media is variable frame rate, Vegas encoding can slow down a lot when it has to decode VFR but I wonder if that's only a problem for the GPU decoder. Remuxing flv,mkv,webm,ts all turn CFR video into VFR

Having the same problem a year later. I switched to DaVinci Resolve which simply doesn't have terrible preview performance, but unfortunately I still have a few videos I started in Vegas that I need to finish.

@Cantersoft you could import your Vegas timeline into Davinci Resolve and finish there. This import works quite well, but only for simple timelines and tracks with edited audio and video events, so no FX, composition etc and no generated media like text etc.

@3POINT Tried that using XML export but didn't have much luck. Thankfully, I have a very modern CPU, so I'm getting by using the legacy AVC decoder.

@Cantersoft you could import your Vegas timeline into Davinci Resolve and finish there. This import works quite well, but only for simple timelines and tracks with edited audio and video events, so no FX, composition etc and no generated media like text etc.

I copied the entire time lines in Vegas 22 and pasted it in 21 and rendered there, worked great.