The Infinite Space Between Words

Computer performance is . You're always waiting for one of four things:

Disk
CPU
Memory
Network

But which one? How long will you wait? And what will you do while you're waiting?

Did you see the movie "Her"? If not, you should. It's great. One of my favorite scenes is the AI describing just how difficult it becomes to communicate with humans:

It's like I'm reading a book… and it's a book I deeply love. But I'm reading it slowly now. So the words are really far apart and the spaces between the words are almost infinite. I can still feel you… and the words of our story… but it's in this endless space between the words that I'm finding myself now. It's a place that's not of the physical world. It's where everything else is that I didn't even know existed. I love you so much. But this is where I am now. And this who I am now. And I need you to let me go. As much as I want to, I can't live your book any more.

I have some serious reservations about the work environment pictured in Her where everyone's spending all day creepily whispering to their computers, but there is deep fundamental truth in that one pivotal scene. That infinite space "between" what we humans feel as time is where computers spend all their time. It's an entirely different timescale.

The book Systems Performance: Enterprise and the Cloud has a great table that illustrates just how enormous these time differentials are. Just translate computer time into arbitrary seconds:

1 CPU cycle0.3 ns1 s
Level 1 cache access0.9 ns3 s
Level 2 cache access2.8 ns9 s
Level 3 cache access12.9 ns43 s
Main memory access120 ns6 min
Solid-state disk I/O50-150 μs2-6 days
Rotational disk I/O1-10 ms1-12 months
Internet: SF to NYC40 ms4 years
Internet: SF to UK81 ms8 years
Internet: SF to Australia183 ms19 years
OS virtualization reboot4 s423 years
SCSI command time-out30 s3000 years
Hardware virtualization reboot40 s4000 years
Physical system reboot5 m32 millenia

The above Internet times are kind of optimistic. If you look at the AT&T real time US internet latency chart, the time from SF to NYC is more like 70ms. So I'd double the Internet numbers in that chart.

Latency is one thing, but it's also worth considering the cost of that bandwidth.

Speaking of the late, great create a profile and even let employers find you.