Quote: Hi all, Just wondering does enabling fast render technology, reduce the final output quality ?

Hello, James!

I don't know if the image quality is reduced but I have noticed that fast rendering(assuming you're referring to SVRT) does shorten the length of the video a tiny bit, but only drops a frame or two in length.

Cheers!

Neil.

Hi jamesd1981

It will mostly depend on the clips and a little in how critically you look at them.

Some background: Fast rendering uses your system's graphics proccessing unit (GPU) to produce your project, and since high-end cards can perform many operations in parallel very quickly, using it can give you significantly shorter producing time. The downside is that sometimes, clips with lots of motion or certain effects and transitions can show some unwanted pixelation or "blockiness."

Most GPUs are designed for gaming, and the goal is to get as much data on the screen as quickly as possible. Even if there are a couple of minor imperfections in a frame, they're quickly replaced by the next frame maybe 1/100th of a second later and nobody will even notice. In the gaming world, as long as the video is fluid, faster is king.

The main alternative is to produce with the CPU, which can take longer because it can only process a few sections at a time (depending on how many cores it has), but generally it will give you the smoothest looking video. CPU encoding is designed to produce the video as accurately as possible, even if it takes longer to finish. If the goal is to have the highest quality in the finished video, CPU producing is usually the better choice.

In the real world, you may see little (if any) difference if you produce two clips from the same project, and my suggestion would be to try that out and see what the differences are. Even if an expert can tell the difference by looking at specific frames, chances are most people won't notice anything distracting.

Basically, if you can produce in 1/2 the time and everything looks good, then by all means use the GPU. If you have a very fast CPU and a only a so-so GPU, you may even see your encoding times be pretty similar. Either way, now you know the benefits and drawbacks of each!

As Neil mentioned, SVRT is the third option and it's by far the best choice if you've only made a few edits AND you'll be producing to the same format. SVRT will analyze your project and simply copy the video from your original clip to the produced video wherever possible.

That means no transcoding/producing at all on all untouched sections (without fades or titles or FX or transitions). That means there's no risk of quality loss and it might only take a few seconds to produce. If SVRT isn't available when you produce, you can click on the Intelligent SVRT button and see if PD can suggest a suitable profile.

Again, a few quick experiments should give you the best answer. Good luck, and have fun

YouTube/optodata

DS365 | Win11 Pro | Ryzen 9 3950X | RTX 4070 Ti | 32GB RAM | 10TB SSDs | 5K+4K HDR monitors

Canon Vixia GX10 (4K 60p) | HF G30 (HD 60p) | Yi Action+ 4K | 360Fly 4K 360°

Thank you both for the replies, I will avoid using fast render for anything important

Having edited many MP4 clips I can say that overall not using the GPU (video graphics card acceleration) offer more consistent video quality. Win 10, i7