[Info-vax] State of the Port - July 2017

[Stephen Hoffman]

On 2017-07-18 21:27:18 +0000, Scott Dorsey said:

> Infiniband is designed for low latency.  If what you need is the lowest 
> possible latency, Infiniband is likely a big win over ethernet.  If you 
> need fastest throughput for bulk transfers, ethernet is likely a big 
> win for you instead.

Ethernet is reaching well up into the same market Infiniband is aimed 
at, and VSI is going to want to and need to go after better Ethernet 
support to start with as it's far more broadly applicable.   Once the 
x86-64 port is out and VSI has 40 GbE and 100 GbE and other related 
support available, then maybe adding Infiniband support gets 
interesting.   This if there's enough of an advantage over then-current 
Ethernet and then-current Infiniband.

Some related reading, both for and against...

https://www.nextplatform.com/2015/04/01/infiniband-too-quick-for-ethernet-to-kill-it/ 

http://www.chelsio.com/wp-content/uploads/2013/11/40Gb-Ethernet-A-Competitive-Alternative-to-InfiniBand.pdf 

https://www.nas.nasa.gov/assets/pdf/papers/40_Gig_Whitepaper_11-2013.pdf


For some of the discussions of why supporting faster Ethernet can 
involve kernel performance and tuning issues, here's a 
previously-posted discussion from the Linux kernel:

https://lwn.net/Articles/629155/



If VSI does decide to go after HPC with OpenVMS, then maybe we see 
Infiniband support added.   But Ethernet is ubiquitous.

And yes, Infiniband is interesting, and clustering over Ethernet RDMA 
(iWARP) might well be patterned after the Memory Channel work, but 
there's a bunch of stuff in the queue ahead of iWARP and Infiniband.




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