[Info-vax] OS implementation languages

[Dan Cross]

In article <uclgav$q0b$1 at news.misty.com>,
Johnny Billquist  <bqt at softjar.se> wrote:
>On 2023-08-29 19:25, Simon Clubley wrote:
>[snip]
>> On a more serious note, I wonder what the maximum rate VMS is capable
>> of emitting data at if it was using the fastest network hardware
>> available.
>
>What a weird question. VMS in itself don't have any limits. It's all 
>always just about the hardware.
>Some software might be able to squeeze more out of the same hardware, 
>but just spin up faster hardware, and you'll get higher throughput. But 
>any system will basically just be limited by the speed of the network 
>hardware, if that item is fixed. You can't go above that. But there are 
>no reasons why you wouldn't be able to get to that point.

I don't really understand this line of reasoning.  At some point
you're running on the fastest hardware available; at that point,
what do you do?  It seems perfectly reasonable to try and
quantify the overhead due to the software stack, and if possible
to optimize it, particularly if your chosen software platform
can't saturate the NIC at line rate.  And even if it can, if it
requires all of the CPU resources on your machine to do so, then
you're starving the platform for cycles that would otherwise go
to the software that all of those hungry network clients want to
talk to.

"Throw more hardware at it" works well until it doesn't, and
when that happens you've hit a wall that you have to get around
some other way.

	- Dan C.