V19 is always slower.

When the render starts the speed is about the same in both V18 and V19. But V19 keeps dropping the speed so half of the project is effectively rendered at 20fps.

Suggest you cycle through every options setting in both v18 and 19 and make sure they're the same. New installs usually copy all your settings from a previous version on the same machine, but I've seen it mess up at times. Like selecting the wrong gpu in Options, Preferences, Video or checking a legacy box on Options, Preferences, I/O.

@Howard-Vigorita

Thanks for suggestion. I checked the preferences. Only thing that was different was thumbnails and legacy hevc decoding. Matching those to V18 made no difference. Also tried the reset and deleting cache.

@fr0sty

Here are some numbers - test clip was mp4 exported from V18, exactly 1 minute long. No effects. I did 2 renders. Second render was slightly faster in both.

V18 did it in 00:47 and 00:43

V19 did it in 01:06 and 01:02

If you use GPU to help rendering it is normal with me that rendervelocity is not constant with Nvidia, but such long slowing down I never saw.
Do you use a GPU, which one en installed driverversion?

Intel is used for decoding and Nvidida for hardware video processing. Nvidia driver version is 466.27, Intel driver is 27.20.1009466.

The render template is Magix avc/aac mp4 (Intel qsv).

I am a bit reluctant to updating the drivers as the same drivers work well in V18 and other programs. Also Nvidia is gaming driver as there is no studio driver for this card.

What NVIDIA card is it?

What NVIDIA card is it?

NVIDIA GeForce 940MX

It's a laptop.

The integrated intel is HD 620

I'm running the trial of Vegas Pro 19.

Just taking a different tangent here .. trial versions of Vegas Pro have in recent years had a rendering limit of under 2 minutes for the project length (i.e. maximum 2 minutes less one frame). I wonder if the OP's project is less tan 2 minutes.

I'm running the trial of Vegas Pro 19.

Just taking a different tangent here .. trial versions of Vegas Pro have in recent years had a rendering limit of under 2 minutes for the project length (i.e. maximum 2 minutes less one frame). I wonder if the OP's project is less tan 2 minutes.

Yes, the project is exactly 1 minute long.

But still, could it be the trial causing this?

But still, could it be the trial causing this?

No

With the paid perpetual version of VP19, I just trialed an exactly 1 minute AVC/AAC MP4 render (not QSV as the MB does not have an integrated GPU), but that 1 minute render to 4K - with lots of VFX - took just under 10 minutes to render and the render speed varied between 1 fps and over 50 fps.

With the paid perpetual version of VP19, I just trialed an exactly 1 minute AVC/AAC MP4 render (not QSV as the MB does not have an integrated GPU), but that 1 minute render to 4K - with lots of VFX - took just under 10 minutes to render and the render speed varied between 1 fps and over 50 fps.

Thanks, @Dexcon

I know the render speed can vary considerably, depending on what effects you use.

But in my case there are no effects and V18 renders the same thing 30% faster than V19.

What NVIDIA card is it?

NVIDIA GeForce 940MX

It's a laptop.

The integrated intel is HD 620

I think it's an issue affecting one or both of those graphics cards. Suggest you try reverting to drivers from the laptop manufacturer's support web site, rather from Nvidia or Intel. Also, I seem to recall other folks reporting issues with the 940MX before v19 came out.

Suggest you try reverting to drivers from the laptop manufacturer's support web site, rather from Nvidia or Intel

I might try this. But the oem drivers are quite old, I think from 2018. Last time I switched between oem and intel/nvidia drivers it was quite a mess.

As V18 and all other programs work fine with current drivers I am not sure I want to mess with this again.

Thanks for suggestion.

I've had to revert to older Intel drivers on more than one occasion and I recommend first using the free DDU utility from Guru3D to avoid complications. It will fully remove the existing driver so you get a clean install.

It's also worth noting the 940mx is on the very, very bottom end of the recommended GPU hardware. That said, it should not work worse than V18.

I've had to revert to older Intel drivers on more than one occasion and I recommend first using the free DDU utility from Guru3D to avoid complications. It will fully remove the existing driver so you get a clean install.

I might give it a go, thanks.

So far I tried updating the drivers to latest version. Made no difference. However turning gpu video processing off improved things somewhat with V19. But out of the possible options V18 with gpu processing on is the fastest.

It's also worth noting the 940mx is on the very, very bottom end of the recommended GPU hardware. That said, it should not work worse than V18.

I am aware of that. Never expected top notch performance from this laptop.

Question is why V19 performs significantly worse compared to V18 with the same hardware.

Question is why V19 performs significantly worse compared to V18 with the same hardware.

Did you compare your settings in 18 and 19 for Options/Preferences/Video and Options/Preferences/ File I/O?

I can confirm that V19 is slower than the last two versions for at least the following media and render format. For testing, the clips were from a Hero4, 2.7K, 60 fps, 1:19 length. No Fx were added--just a straight render using MagicYUV 8-bit YUV 4:2:0, a lossless digital intermediate which is CPU only. Here are the results:

V17 - 0:47
V18 - 1:02
V19 - 1:11

V19 was a bit slower than V18, but both V18 and V19 were quite a bit slower than V17. Why? I have no idea.

I did test with a HEVC GOPro7, 2,7 50p file of 23 seconds, rendered to FHD 50p with Magix AVC Nvenc on laptop from signature.
The results
VPro 17 - 0:22
VPro 18 - 0:17
VPro 19 - 0:16
Rendered the same with QSV in V19 - 0:14

Thanks @wwaag and @j-v

Your results are interesting. I can only test with intel qsv. The preferences are the same in both V18 and V19.