Hacker News Reader

Comment by swalsh | Hacker News Reader

I know nothing about hardware, but i'm curious. Isn't a whole lot of the speed we're getting out of systems these days a ramification of putting everything on the same piece of silicon? If each component is physically separated, isn't that going to impact latency?

View on HN

Think of the cache pyramid.[0] Latency may be higher, but if there is enough work / data then it's still efficient to do work remotely / put data farther away.

From what I understand, the article is about two things:

1. Hot swappable components.

Oversimplified, but imagine being able to add / remove CPU and RAM to your server like you can with disk space and USB thumb drives.

2. Shareable resources / load balancing.

If one server is using all its CPU and another is using all its RAM, they can now use each other's resources.

You know how AWS is on-demand, scalable computing? This is the same thing but at a hardware level with CPU, RAM, disk, and network resources.

[0]: http://static.ddmcdn.com/gif/computer-memory-pyramid.gif

Memory(except on chip caches), disks, and various other peripherals arn't on the same chip in traditional servers.

They're basically taking the backplane of a motherboard and spreading it across a whole rack instead of inside a single server. Especially memory would take a latency hit if all you do is extend the "cable" length between the CPU and memory, which is why they also need a much faster interconnect.

No, in recent years speed gains are found by adding more processors. I don't have the chart on hand, but a couple years ago the growth rate of speed of a single chip got much lower.

Reply on news.ycombinator.com