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Cray-1 vs Raspberry Pi

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Re: Cray-1 vs Raspberry Pi

#141
post #30
post #9

There's a line in the Jurassic Park book where a character is made suspicious by an offhand assertion (by Nedry) that he is using a multi XMP system . Rpi4s are nice, in a sense, because you can only rarely honestly claim that the speed of the system is holding you back. Most times, presumably, it's the efficiency of the operations you are telling it to execute.

> Rpi4s are nice, in a sense, because you can only rarely honestly claim that the speed of the system is holding you back. As someone who uses them for a variety of purposes, I gotta note that they have pretty huge limitations. Like, the moment graphics enter the picture (no pun intended) you’re moving an order of magnitude slower than most desktops or laptops. Not to mention that support for hardware video encode/de…

Requiring a small nuclear reactor to power it aside, the Pi 5 feels far more like it's up to the task of a full desktop machine. Admittedly I haven't tried anything but headless workloads on mine so far, but it's so much snappier it's genuinely unreal. I'm really looking forward to seeing how much faster lidar localization and just SLAM in general runs on it once ROS support is sorted.

Although they did remove the h264 decoder and encoder which is a bummer, like you say it's hard to get working support for it anyway. Vulkan + regular GPU acceleration might be easier. And it still only has 4 cores which is crap for desktop multitasking.

Re: Cray-1 vs Raspberry Pi

#142
post #22

Earlier quoted context omitted.

Those are largely simd but not vector.

That's fair. I haven't spent any time looking through the RISC-V vector extensions yet. I look forward to it, though.

They are said to be "inspired" by classic Cray vector instructions, although I have of course never used a Cray :-( so I can't comment on how true that is. I did use a Convex C2[0] for a while which also had real vector instructions, but it was all hidden behind a compiler option.

[0] https://en.wikipedia.org/wiki/Convex_Computer

Re: Cray-1 vs Raspberry Pi

#143
post #52

It's wild to imagine that 40 or so years from now, someone will have a drawer full of cheap plastic boxes, each with more power than the fastest computing cluster of 2023... promising to themselves that one day they're finally going to build that hobby project with one of them.

You really think so? Aren’t we at the end of Moore’s law, so I’m really doubtful that we’ll see massive leaps like that.

> Aren’t we at the end of Moore’s law

Three semi manufacturers are telling their investors they'll be at 2nm (or something) in late 2024 or 2025. So no, Moore's law has not seen its end, despite ~40 years of predictions to the contrary.

Re: Cray-1 vs Raspberry Pi

#144
post #53

This is actually quite depressing considering the amount of Raspberry pi's doing tasks like watering a plant, Reminds me of Marvin the paranoid android.

I've come to the conclusion that the value of the RPI is not so much in the hardware platform but rather in being the cheapest Linux running computer you can buy. Its much easier to program for than any embedded board.

> Its much easier to program for than any embedded board.

Indeed. I work in both MCUs and full-featured Linux environments and there is zero value to using the former for non-safety critical, non-power constrained, low precision applications. Running a sprinkler system on an RPi is an entirely reasonable choice: you have ample storage for history, trivially simple remote control using a variety of protocols and media and ample compute to operate high level languages and run easily maintained programs, including nice-to-haves like continuous integration of public weather data to optimize your schedule against prevailing rainfall.

Can you shoehorn all that into a ESP32 + micropython or whatever? Sure. I'll bet someone already has. And they spent 10x the time it would have taken otherwise. At least.

Re: Cray-1 vs Raspberry Pi

#145

When I see comparisons like this, the first thought I have is not the benchmarks, but rather what the most “heroic” real-world calculation of the day would have been on something like the Cray-1, and how to replicate those calculations today on something like a RPi. Weather/climate models? Rad-hydro? The fidelity would almost certainly be super low compared to modern FEA software, but it would be a fun exercise to tr…

I toured an NCAR (National Center for Atmospheric Research) facility in Boulder around 1979; got to sit on a seat on their Cray-1. So yes, weather and climate calculations.

Re: Cray-1 vs Raspberry Pi

#146

Earlier quoted context omitted.

"The comment above was for the 2012 Pi 1. In 2020, the Pi 400 average Livermore Loops, Linpack and Whetstone MFLOPS reached 78.8, 49.5 and 95.5 times faster than the Cray 1." Apart from the Cray-1, that whole section is also worth reading for some interesting insights into relative speed differences between various modern CPUs as well. (Though I do wish it was presented in table rather than narrative form, it’d be a…

Ok, do Pi 5 now

Multiply Pi 4 results by 3 and you have the rough ballpark.

Re: Cray-1 vs Raspberry Pi

#147
post #64

Earlier quoted context omitted.

No. The Cray-1 ran batch processing jobs, mostly scientific simulations which took hours or days to compute. It had a terminal interface and wasn't used for real time interactive applications.

IIRC, in real world installations the Cray would have been paired with a minicomputer or mainframe.

So should we pair with a PiPDP-11?:)

Re: Cray-1 vs Raspberry Pi

#148
post #27

Earlier quoted context omitted.

I’m more impressed that the cray was that fast such a long time ago tbh

That all began with the CDC 6600. https://en.m.wikipedia.org/wiki/CDC_6600

> CDC's first products were based on the machines designed at Engineering Research Associates (ERA), which Seymour Cray had been asked to update after moving to CDC.

> Cray has been credited with creating the supercomputer industry. Joel S. Birnbaum, then chief technology officer of Hewlett-Packard, said of him: "It seems impossible to exaggerate the effect he had on the industry; many of the things that high performance computers now do routinely were at the farthest edge of credibility when Seymour envisioned them.

> One story has it that when Cray was asked by management to provide detailed one-year and five-year plans for his next machine, he simply wrote, "Five-year goal: Build the biggest computer in the world. One year goal: One-fifth of the above." And another time, when expected to write a multi-page detailed status report for the company executives, Cray's two sentence report read: "Activity is progressing satisfactorily as outlined under the June plan. There have been no significant changes or deviations from the June plan."

> Cray avoided publicity, and there are a number of unusual tales about his life away from work, termed "Rollwagenisms", from then-CEO of Cray Research, John A. Rollwagen. He enjoyed skiing, windsurfing, tennis, and other sports. Another favorite pastime was digging a tunnel under his home; he attributed the secret of his success to "visits by elves" while he worked in the tunnel: "While I'm digging in the tunnel, the elves will often come to me with solutions to my problem."

Well Seymour you are an odd fellow, but I must say you design a good mainframe.

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