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Comment by SlavikCA | Hacker News Reader

What are typical use cases for needing 25Gbps?

Author talks about 4k video, but AI tells me that for "4K production mastering (ProRes 422 HQ, 4:2:2, 10-bit)" the rate is under 2Gbps.

I'm not saying it's not needed, - just curious.

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Running local LLMs split across machines. Pretty sure the author has some other posts about doing that.

Edit: https://www.jeffgeerling.com/blog/2025/15-tb-vram-on-mac-stu...

correct me if I'm wrong but wouldn't a Thunderbolt 5 cable $79 from Apple[1] work better for that? It gets 80 Gbps and doesn't need any extra equipment.

[1] https://www.apple.com/shop/product/mdw94am/a/thunderbolt-5-u...

We refurbish laptops and hence distribute .iso / ipsw images to various refurbishing stations. (or also, think of PXE/network boot situations). More images x more laptops refurbished at once = more bandwidth.

Obviously it's possible to move this to a NAS, not use a mac, etc. etc. - but just wanted to chime in with my little use case of moving multi-gig-files around. :-)

I was just looking for a thunderbolt-sfp solution. Super timely!

> Author talks about 4k video, but AI tells me that for "4K production mastering (ProRes 422 HQ, 4:2:2, 10-bit)" the rate is under 2Gbps.

That'd be the rate for 1 stream at 1x playback. Multiple streams because of overlays/crossfades/etc... along with playback at >1x (such as during rendering in particular) will change that significantly.

NAS stuff can benefit greatly and straightforwardly.

A typical NVMe SSD can easily do sequential reads at 7GB/s, which outpaces a 25Gbps connection by more than 2x. NAS is more typically backed by SATA HDDs, but there's some relatively easy way to put an NVMe disk in front of them as a cache.

Do you ever _need_ it? Perhaps not, but there's plenty of common activities just stemming from NAS usage which see a linear speedup, and would continue to get faster up to 100Gbps even.

The primary use case is the same use case as having 388 hp in a Porsche Carrera. It's cool and it's fun to go fast.

ProRes is a compressed and encoded format. In order to become ProRes, it needs to be uncompressed and decoded at some point. uncompressed and unencoded is easier to work with on the rendering side, but much heavier on the data side. Ask your AI about the DPX file format.

AI tells that for DPX 4k 60fps it's ~17Gbps

What if it’s uncompressed footage at 60fps? And dealing with many shots. And on top of that maybe working with multiple projects in parallel.

Normal 4K editing workflows are fine with even 2.5 Gbps wired networking (wired to make latency like when scrubbing not-horrid)... 10 Gbps more necessary if editing ProRes RAW and doing multicam (4-8 streams simultaneously).

I'm in a never-ending pursuit of cutting time when transferring large files though — AI models is one thing, but I have 100-200 GB projects I transfer across for backup or import (using an external TB5 drive capable of 3-5 GB/sec), and if I can do that in 1 or 2 minutes per project instead of 3 or 4, that's a noticeable speedup.

Definitely overkill for 98% of my workflow though. 10 Gbps is fine.

If you're editing video you're not just streaming in real time one copy. You have many streams that you're going to want to work around quickly.

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