I wanted to see how much I could use. Upped to 5gb and noticed a massive drop. So played with different settings to see the effect. Highest I can go is 2100 before it slows down. Also tested 0 while I was at it and biggest slow down of all

Vegas just can't use RAM normally since version 15

Vegas just can't use RAM normally since version 15

What do you consider as normal?

I know a lot of people set the ram to zero to improve stability (no problems here with VP16) but this seems to increase final render times by 20%

Setting RAM to 0 is indeed slowing down rendering time, but switching GPU OFF instead is even more slowing down rendering time. Just rendering a few clips, what is here often shown as a rendering test, doesn't effect stability, but as soon as some composting is done ( a few PIP's for example) the stability of Vegas or Movie Studio is gone=crash. With stability problems expected, I just try first RAM set to 0, when that doesn't work I put it back to 200 and switch OFF GPU, that always helps, despite slowing down the rendering speed.

Better having ONE slower render without problems, than SEVERAL fast ones with crashes.

I see this problem existing already several Vegasversions and at the moment after the 5th update, I´m really afraid if this problem will ever be solved. It also keeps me waiting to buy a new PC, because I hear here the same problems from users who have far better hardware than I have.

@3 point : here the same issues on both systems . I re-installed build 307 and that seems to behave better and seems to be using dynamic RAM and all cores ( when previewing ) as sony vegas pro 13 did .

In that version , I can dedicate 32 GB of dynamic RAM ( GPU=OFF ) and enjoy realtime working and previewing and use dynamic RAM as before ( i.e. sony vegas pro 13 ) .

All  later versions , RAM is barely used as is CPU power when previewing .

So something ( at least here ) must have changed dramatically in versions later than build 307 .

Am only interesting in comfortable realtime editing , rendering is done while working at the other station and whether that takes 3 seconds longer ( after 72 hours and more of editing ) is the very very last of my concerns.

My system specs are in my profile and the tests at my systems are done with a very simple m2t file , captured by vegas ( 1440x1080 PAL ) , so very simple short 10 minute file ( old part of video which we had to add into a new clip  which we are editing in sony vegas pro 13 , to be sure ..... )

Am only interesting in comfortable realtime editing , rendering is done while working at the other station and whether that takes 3 seconds longer ( after 72 hours and more of editing ) is the very very last of my concerns.

My system specs are in my profile and the tests at my systems are done with a very simple m2t file , captured by vegas ( 1440x1080 PAL ) , so very simple short 10 minute file ( old part of video which we had to add into a new clip  which we are editing in sony vegas pro 13 , to be sure ..... )

@wilvan +1

That's also my opinion, I need smooth editing and quality rendering. I'm also re-editing older projects (since 2006) with HDV footage and do stabilize those now with the Mercalli4 plugin and that use makes VegasPro later than Version 13 necessary.

I also edit with VMS16, which looks to me also more stabile than VPro16. When I render a VMS16 project in Vpro16, I get earlier stability problems than when I render the project in VMS16.

@wilvan it's your quadro cards. They don't play nice with Vegas. More info and a workaround here https://techgage.com/article/exploring-magix-vegas-pro-16-gpu-performance/

@mintyslippers : As I did explain here above  , GPU=OFF , meaning I don't make use of the quadro cards in vegas pro but instead make use of all CPU power and lots of RAM . And that stopped workig properly after build 307 . ( by the way , that workaround , when turning GPU=ON , is somethng I am doing for a long time in nvidia control panel , also for After Effects and Avid Media Composer )

On my system there is almost no difference in render time with Dynamic RAM Preview: 0, 200, 1000. Render time is almost the same (tried not red car project with MagicAVC, 1080-60p, 32-bits, encoder -- CPU only).

There is big difference when I switch OFF GPU in Vegas settings (render time is doubled).

I ran the red car again with different DRAM preview settings, and for my system (see profile) I do not see any benefit for increasing DRAM preview. All renders from 0 to 3000 MB are 26s, then they start to increase in render time. I made a chart, horizontal scale is logarithmic. I always render with DRAM preview to 0 as it avoids crashes and even when it is stable it can avoid artifacts in the final render. Especially complex compositions with speeding up/down and a lot of plugins are vulnerable.

I wonder why my ram at zero has such a negative effect. I too have an RTX although a 2060. Just less cores. Amd processor.

@mintyslippers I remember from the past that there was a (slightly) longer render with DRAM to 0 on my system, but that could have been with a different project or even a previous videocard or processor combination (Intel + Nvidea). And certainly with a different Vegas Build. But even then it was never worth the risk to not use 0 with the very small increase in render time.

Here is the same graph, but I redid the test on Vegas 15, interesting enough there is a difference between DRAM at 0 for Vegas 15, and in general Vegas 15 red car renders almost 30% faster than Vegas 16 on my system (less feature heavy maybe?), shocking!

Render as usual for this types of benchmark: all default settings MAGIX AVC/AAC - NVENC

Sorry for stupid question, but should I modify the VP11_benchmark project or render template to get compareable numbers? Like changing rendering quality to Best?

Now I have also done this test on my system. VP16 build 424, Ryzen R7 2700 no OC, AMD R9 380, MAGIX AVC/AAC - VCE

0MB 27s
10 - 200 MB 19s
256 MB 23s
1000 MB 29s

If the rendering speed decreases at higher values, I can see a significant increase in GPU copy activity.
My conclusions: The default value is suitable for rendering. Only if the known problems occur must be chosen 0 MB. Larger values are required only for dynamic RAM preview (Shift-B or Num-0) and should be reset before rendering because they slow down rendering.