Graphics cards for H265 on the fly encoding questions please?

[Chris Wilson]

I am an amateur radio fan and have a modest set up for transmitting and receiving amateur TV digital pictures and videos via the `Es Hail geostationary satellite..

H265 being better quality for a given file size and bandwidth would improve my transmissions which are currently in H264 encoding.

As such I want to build a dedicated Windows PC for this purpose. Inputting a live hdmi HD video stream and outputting it in H265 format. Given the scarcity and price of graphics cards right now I have shown an interest in an EVGA GTX1070 SC2 card, used, an acquaintance is selling. Is it likely up to the job or should I look to spend more on a more modern card?

I am also going to trial an external hdmi to LAN encoder box from Ebay which may allow me to encode hdmi on the fly. My transmitter is on the end of a LAN cable outside, by the satellite dish.

If I stick with Windows 7 Pro 64 bit which I am comfortable with, am I at a great disadvantage to moving to Windows 10 or 11? What would be the best processor and motherboard for Windows 7 and this rather specialised application, I know most later Intel processors will use some of their capability to encode H265 encoding, does having a graphics card GPU doing that render that part of the CPU's capacity redundant? I am also somewhat aware that very late processors and motherboard socketing may not play well with Windows 7 any longer.

I have a PC running an Intel i7 6700K processor on a Gigabyte H170-D3HP motherboard with 16 Gb RAM, which I am using for something else, can I improve much on that and still use Win 7 64 bit?

Thanks for reading and for any advice you might share.

 

[ToOo]

With handbrake I've found that while nvenc x265 is very fast it results in significant increases in file size vs CPU encoding for x265.

Any Pascal gpu or newer can support nvenc x265 except I think gt1030 so the gtx1070 should be fine

Can't give any insight on AMD gpus

 

[Chris Wilson]

OK, thanks for the info To0o, appreciated

 

[Cyber-Mav]

Turing 116 and up has h265 nvenc with b frames support which is considerably better than Pascal encoder

 

[ToOo]

You are quite correct, b frames improve hvec encoding by 15- 20%, but balancing that out you need to consider that all Turing chips have only one nvenc engine while the gp104 (gtx1070) and better Pascal chips have two and so massively out perform Turing when transcoding multiple streams.

 

[loftie]

If bandwidth is the most important factor, as ToOo says, GPU encoding of files makes the files larger than doing it on a CPU.

I know most later Intel processors will use some of their capability to encode H265 encoding, does having a graphics card GPU doing that render that part of the CPU's capacity redundant?

This could be one of two things off the top of my head, and i suppose my experience is coming for using Handbrake only so YMMV. It could be decoding on the dedicated video hardware decoder in the CPU, or it could be encoding on the hardware encoder (aka Quicksync). Actually I think you might be able to use the GPU part to encode too, but the answer to your question WRT this would be the same. Which is that having a GPU do the encoding/decoding will mean the CPU hardware encoder/decoder is doing sod all.

If you can test the 6700k doing H265 without using the hardware encoder (so using software encoding) i would do so. Might be capable of doing it by itself! You could also test quicksync to see if that's either acceptable or capable or h265. And finally, depending on what you're streaming, you may not even find that much of a size benefit to be honest.

 

[Cyber-Mav]

From my testing cpu encodes are always better for smaller file sizes