Viewing a single comment thread. View all comments

Sarah_Rainbow t1_iwgfy31 wrote

Serious question, what is the need for supercomputers when you have access to cloud computing in all its glory?

0

dddd0 t1_iwghfua wrote

Interconnect

Supercomputer nodes are usually connected using 100-200 Gbit/s fabrics with latencies in the microsecond range. That's pretty expensive and requires a lot of power, too, but it allows you to treat a supercomputer much more like one Really Big Computer (and previous generations of supercomputers were indeed SSI - Single System Image - systems) instead of A Bunch Of Servers. Simulations like Really Big Computers instead of A Bunch Of Servers. On an ELI5 level something like a weather simulation will divide the world into many regions and each node of a supercomputer handles one region. Interactions between regions are handled through the interconnect, so it's really important for performance.

18

LaconicLacedaemonian t1_iwgt8rr wrote

I maintain a 20k node cluster of computers that pretends to be a single computer. The reason to do it that way is if we 10x our size we can 10x the hardware and individual machines dying are replaced.

3

_ytrohs t1_iwgziml wrote

and cost.. and hypervisor overhead etc

1

krokotak47 t1_iwghwko wrote

So cloud computing literally happens in the sky and we don't need hardware for it?

10

Sarah_Rainbow t1_iwgikys wrote

Why else would i buy a telescope for?!??

I mean with the cloud you can have your computing power distributed over a larger geographic area, plus the hardware cost is lower and setting it up is relatively simple. I've heard stories from the physics department at UofT where students preferred to use AWS over other available options (supercomputers in Canada) to run their models and stuff.

0

Ericchen1248 t1_iwgnt5q wrote

While I don’t know the costs for them. I would wager the students chose to use AWS not because it was cheaper but because registering/queueing for super computer time is a pain/can take a while.

2

krokotak47 t1_iwgq1bd wrote

I believe it all comes down to cost. I've seen some calculations on reddit that were like 30k USD for the compute needed on Amazon ( absolutely no idea what the task was, something with GPUs). So that's obviously not possible for many people. What's the price for a supercomputer compared to that? I imagine it may be free for students? In my university you can gain access to serious hardware ( I'm talking powerful servers, not comparable to a supercomputer) by just asking around. What is it like in bigger universities?

1

Pizza_Low t1_iwhkwyo wrote

Cloud is great for when you want to rent someone else’s computer space. It can be cheaper than building a data center, maintaining the hardware and software, expand and contract dynamically.

For example a ton of servers can be brought online for something like if Netflix was streaming the super bowl. They might suddenly need 3 times the servers they normally need, cloud is good for that sudden expansion, but tends to be more costly for regular use.

Super computers are great for lots of calculations very quickly. For example you want to simulate the air flow of individual air molecules over a new airplane wing design. Or some other kind of complex mathematical modeling in science, or finance.

1