Hacker News Reader

Comment by areoform | Hacker News Reader

https://developer.apple.com/documentation/technotes/tn3205-l...

MacOS has supported RDMA over thunderbolt since March 19th.

That is just RDMA itself and seems to be aimed directly at distributed inference (no surprise there!). Now they need to update the SMB driver to make use of it.

Yeah, raw RDMA is one thing, making sure other protocols can use it is another... hopefully Apple gets there, but right now SMB with RDMA is probably a tiny, tiny niche.

I do wonder what Apple's custom-built servers are running for networking. I wish they still made Mac Pro-level chassis specifically for better IO. Thunderbolt 5 is nice, but far inferior to a PCIe x16 slot (which can hit 400 Gbps networking) nowadays.

I'd suspect that (from Apple's perspective) any form of file sharing (other than iCloud) is now considered 'extremely niche.'

If they were focused on the needs of the kind of person who moves enough terabytes of files around to need this kind of speed, we'd see them still making either computers with slots, or first-party 25Gbps networking.

I'm not really trying to criticize them for it -- Tim Cook's bean counters clearly did the math and they're certainly free to optimize their Mac R&D spend for things that'll sell college students MacBook Neos and Airs, rather than worrying about the MKBHDs, Linus Sebastians and Jeff Geerlings of the world (this is just a list of people I've seen using extremely fast networking).

Might their professionals market segment (designers, video editors, 3d artists, and so on) still be using thunderbolt and LAN storage? This was the case ~7 years ago when I worked adjacent to these sorts of users. Video files are huge and expensive in time and money to transit with cloud storage providers.

I do 8k video editing on a Mac Studio. Files are often multiple TB (raw camera capture which I have to encode to ProRes). Moving this kind of bandwidth is absolutely what I have to do and Apples’ bad networking is a blocker I’ve discovered.

Apple used to even sell Xserve RAID and SAN software specifically to cater to the higher end users who needed fast networked storage (research, broadcast, media).

They kinda hit a standstill on the networking side as they moved to the trash can Mac, and I think that had killed momentum towards any high speed IO besides the Thunderbolt ports moving forward.

I was hopeful they'd keep the Mac Pro going into the M-series era but after one version... it's gone.

I'm sure they are, but there just aren't that many of them. When you include only real professional "Hollywood" people plus the elite tier of YouTubers who can easily afford to drop $10,000 on a computer (The 'Mac Pro' target market, in other words) we're talking about a tiny niche to Apple. Both within the "Mac" segment, and even more so when compared to the company's overall portfolio that includes iPhone.

So, it seems that Tim Cook decided at some point that while it's nice to make $5,000 in profit from a Mac Pro sale every day or two (okay, I kid, I'm sure they sell a bit more than 365 a year), even if they hang those "pros" out to dry completely and they defect to Windows, Apple would be better off spending their time focusing on ways to make the MacBook Air and Neo more attractive or profitable because they move orders of magnitude more units of those.

Note: I don't like this, but my feelings have nothing to do with it, I think it's just a classic Tim Cook Numbers-first business decision

For the record this is officially called "SMB Direct":

* https://learn.microsoft.com/en-us/windows-server/storage/fil...

* https://docs.kernel.org/filesystems/smb/smbdirect.html

Is RDMA something worth looking into for connecting two random Linux computers? I've been extremely underwhelmed by the stability and performance of my NFS shares.

Yes, nfs with rdma will increase your performance significantly.

If your storage devices are native PCIe and your network is actually fast enough and your nics and switches have the proper hardware and driver support and your switches are properly configured and your nfs client and server configurations are tweaked just so, and you hold your face in just the right position

The perf is amazing

I do have stable diffusion running on a non-Nvidia GPU, so I'm familiar with the manner of rituals required before contemplating installing system updates or even suspending the system.

Now, I'm off to determine if an eMMC M.2 module is a native PCIe device…

ROCE do require proper nic/switch tuning. But if you go all in on Mellanox NIC's and switches, its basically on knob on the switch: roce

If you buy CX3 and Mellanox SX6036(easy fan adjustment and low power usage) switches on Ebay for cheap. Which are great up to 56Gbps. You can run infiniband which is way easier to setup, just remember you still need to enable IP over IB to start the handshake for the RDMA connection.

They also said something about stability, which I doubt would be improved by adding RDMA into the mix.

NFS 4.1 / 4.2?

Reply on news.ycombinator.com