Thanks, that's interesting. I guess the lowly GTX cards don't even factor into the benchmarks LOL

An aside:

Your 65 Watt processor is six years old.

An aside:

Your 65 Watt processor is six years old.

True, do you think that will be my bottleneck in terms of performance?

It probably will be when you get a more capable GPU. Check Vegas requirements and see if 6 or more cores is recommended for 4K content.

@Neel @john_dennis Hi, Vegas requirements, (prob min spec requirements)

@Neel If you can fit a new GPU in & try it see how it does no harm's done, if it's no good you've got a decent card to put in a new PC,

Thanks Gid. I may have to look at a new CPU/RAM/Mobo combo, that may be better bang for my buck.

An aside:

Your 65 Watt processor is six years old.

True, do you think that will be my bottleneck in terms of performance?

Not in this example. That's the point of hardware encoders. I don't think CPU or GPU (processing) should go up when changing from Nvenc H.264 to Nvenc H.265, Vegas renders the frames, NVENC encodes them. Your encoder I think is the same as that in the rtx 3060. So that is strange, when I had an rtx3080 I don't recall there being a dramatic slow down when encoding H.265 compared to H.264.

Are you sure you're using the identical settings in Vegas encoder settings only changing between Nvenc H.264 and H.265?

Maybe it actually is the case H.265 NVENC on 1650super is much slower, I know there's active users on this forum with your same card, they could test that idea

@Neel @john_dennis Hi, Vegas requirements, (prob min spec requirements)

@Neel If you can fit a new GPU in & try it see how it does no harm's done, if it's no good you've got a decent card to put in a new PC,

Strange, they say minumum 7th-gen processor with 8 cores, but the 7-gen Intel's max out at 4 cores, AFAIK.

7th Generation Intel® Core™ i7 Processors Product Specifications

Is the OP actually using NVENC in order to compress the HEVC video? If using Mainconcept (CPU), it will definitely render much slower.

Thanks so much, this is certainly the case. Using the Intel encoder, this 90 second video took over 2 hours to render. Using NVENC with my Geforce GTX 1650 Super, it rendered in 4 minutes 22 seconds. The difference is huge....