Laggy preview window?

[Carvonis]

So I record gameplay with the program Mirillis Action, and I have the latest version, the raw footage itself is in high quality and the audio as well, and there is no lag whatesoever, the recording program is amazing, however when I want to edit it in this program, Sony Vegas Pro 14, the preview window is laggy and choppy and the same with the audio. I have a decent computer, I have a GTX 970 with 4GB of VRAM and an i7 processor. Do I need a better cpu or something or how do I fix this. I've tried many things such as the preview window setting it to half size and auto and such and also reducing the ram, I just dont know what any of that stuff means I've only followed the steps online such as the youtuber MovieStudioZen but it still isnt enough. Any help would be appreciated, thanks.

[😎Macula😎]

Have you tried to render video and see if output video still lags?

[wakeme]

here is the list :

1.
Vegas's view window settings : Preview-->Auto

2.
time line thumb nails : set to Head Center Tail ( just 3 )
Full thumb niails is a really big performance hit .

3.
if the source footage has extemely high bit rate , force Vegas to make a low bit rate Proxy file .
if 4k footage is inported , vegas automatically makes a Proxy file upon import ,
causing the import process to do a Render ( a slow import ) .

what is the bit rate of your source footage ?


i use 1. and 2 .
with 1080 h.264 bit rate 14 Mbps source footage , and time line performance is good ,
( straight video\audio , No video-FX effects used )
( 5.1 audio can add some additonal overhead )
running CPU at 2.4 Ghz . using CPU only .
No GPU .


Now , if i were to add some Video FX effects , time line may now choke ,
that is why you then make a Dynamic RAM Preview( render ) of a small
FX edited portion , to see how the effect is working . ( Tools menu )