beanpaisly

[beanpaisly]

It does look like Windows in its current form may not be well suited for low latency high rate uncompressed streams over commodity ethernet adapters. Linux with Wayland is another story. Although there are a couple of Windows options that have not been explored, namely:

– a Custom zero copy Soft-RoCE driver on both ends that pins Video RAM.

Do Linux/MacOS versions of NoMachine support standard non-VRAM Soft-RoCE ?

– Thunderbolt to Thunderbolt zero copy or a variation on RDMA i.e. not Thunderbolt Networking

Number of laptops and desktop motherboards supporting Thunderbolt will grow exponentially within a year, hence, it does make sense to look at zero copy over Thunderbolt.

Would NoMachine be willing to explore these options??

[beanpaisly]

Hi fra81,

While I do appreciate the response, calculations provided make sense only for 1GbE connections.

My question, however, referred to 10GbE links.

Please consider the following:

10GbE Transfer Rate per second in MB = 10000000000/10/1024/1024 = 953.67MBps

Size of a single 1920×1080 frame = 1920 * 1080 *4/1024/1024 = 7.91MB

Number of 1920×1080 frames possible to transfer over 10GbE per second = 953.67/7.91 = 120.56fps

Latency per frame = 1000/120.56 = 8.29ms

Rate required to transfer 1920×1080 frames at 60fps = 1920*1080*4*60*8 = 3.98 Gigabit/s

4Gbps is very much achievable on a 10GbE link.

4Gbps may even be achievable over a 5GbE link using UTP.

It looks to me as though total end to end latency in the vicinity of 10ms  is a possibility over 5GbE/10GbE connections if uncompressed option is provided. Would you agree??

[beanpaisly]

No worries, Britgirl

Could Fra81 please include recommendation on the following:

– How to achieve sub 10ms latency on an inter-lan setup i.e. within a few meters away?

– Should a USB Bridge cable be used? i.e. one of the 5GbE cables like the Streaming Cable for LattePanda.

– Assuming that uncompressed RGBA framebuffer feed will generate sufficient CPU activity to cause latency issues, is there a good option that is not TCP or UDP? i.e. a different Layer 2 option that would work wonders when going directly PC to PC on consumer network cards(not RDMA)??

Any insights much appreciated.

[beanpaisly]

Hi Britgirl,

Apologies for not pointing out what the problem actually is – the problem is Latency i.e. not chasing quality improvement.

I would agree with you that it doesn’t make sense to use an uncompressed session just to improve quality.

It does, however, make perfect sense to have an uncompressed session to improve latency.

Compression adds at least 5ms-10ms of latency and occupies video encoder on the host. What if I want to edit videos remotely and require this video encoder? Not to confuse you, this query is not related to hogging video encoders but concerns latency.

Scenario of uncompressed session makes sense when host and client are in close proximity under the same roof with requirements of minimal latency.

And by minimal latency I mean under 10ms in total. Ideally under 5ms.

Would you please be kind enough to add an uncompressed session option for the sake of latency?

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