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Comment by jermaustin1 | Hacker News Reader

This is actually mildly surprising to me that the Raspberry Pi is only 4.5x faster. I would have bet 10-20x faster just because of how much time has passed and all the talk about: "your cellphone is 1000x faster than the Apollo computers" that I've been hearing since the time of the t-mobile sidekick.

I've always taken them with a grain of salt, but even if they were only an order of magnitude off, a Pi is loads faster than a sidekick. And sure the Cray is loads faster than the Apollo computers, but I wouldn't have thought it was THAT much faster.

I am amazed.

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The Cray 1 was way ahead of its time. It implemented SIMD vector instructions to speed up numerical computation, was liquid cooled, and ran at 80 MHz (in 1976). The chief architect, Seymour Cray, was kind of a genius, and is responsible for designing many other pioneering machines.

Also, fun fact, it didn't have a CPU. It used all discrete logic chips, and was wired by hand, with lots and lots of wire. IIRC Seymour Cray liked to hire women to do the wiring job, because they had an easier time fitting inside the computer core to wire it, and doing detailed work because they had smaller hands.

> Also, fun fact, it didn't have a CPU. It used all discrete logic chips, and was wired by hand,

That's how CPUs were built back then. What it didn't have was a single-chip CPU, or a microprocessor.

Next up: "The Model T Ford didn't have an engine, it had this gasoline-burning device to provide motive power."

Lots and lots of wire, yes, with each one cut to a specific length so that all of each gate's input signals arrive at the same time. That's why the backplane looks like a mess of wires hanging down due to seemingly being way too long.

Note that modern RAM has length matched traces.

Take a look at all the PCB traces near RAM and CPU. You can see them 'squiggle' looking for matching-space at either end of the RAM/CPU connection.

PCBs make things like consistent length matching easier. All circuit boards have near identical lengths, controlled impedances and other features that support ... Well... Effectively 6-billion baudrates for DDR5.

6000Mhz DDR5 with 64-bits per half-clock (3000Mhz clock so 6000 transfers per second) has a bit every 5 centimeters or so.

And that kinda makes it unfair to the Raspberry, maybe not the RPI1 but I'm pretty sure that the RPi4 (rated at 78x the Cray) running code in compute-mode would thrash the Cray 1 even harder (yes, not entirely comparable but since you probably didn't get full throughput on the Cray with regular C code then using the GPU on the RPi should be fair game).

> SIMD vector instructions

Err...

That term is used to describe modern vector instructions that are NOT vector instructions in the classical Cray-sense. Modern CPUs use wide registers that can be regarded as vectors of 2/4/8/... values. Cray used memory-to-memory variable-length vectors.

I'm not saying that "SIMD vector instructions" is an incorrect description of what the Cray machines did, I'm saying that the term usually means something else today.

The fluorinert coolant was really neat stuff too. Inert, so you could submerge electronics in it to cool them. I was able to find recycled coolant and used that to do the liquid cooled build for my dual celeron system where coolant flowed over the board/cpu. Knowing what I do now... I should have been far less cavalier with the stuff.

You’re not wrong, since the 4.5x number comes from a comparison with the rPi 1.

The rPi 4 is over 10x faster than the 1.

The original article points out that the raspberry pi 400, with the benchmark targeting 64 bits, was about 80x Cray for the same benchmark which was 4.5x for the rPi 1.

Raspberry Pi 5 advertises a 2-3x performance gain over earlier versions, though this wasn’t benchmarked in these tests.

Aren't these also in FLOPS? The rpi isn't exactly a floating-point monster. Hell, until the Pentium, Intel CPU's weren't guaranteed to even have an FPU.

As to ARM in general, here's a post about how ARM-1 compared to the 387: https://retrocomputing.stackexchange.com/questions/24826/did...

> Hell, until the Pentium, Intel CPU's weren't guaranteed to even have an FPU.

80486

486SX

The 80486SX was introduced two years after the 80486 and did not have an FPU (unless it was purchased as an option).

I think the meaning of my comment was clear: the 80486 was the first Intel CPU guaranteed to have an FPU. I didn't say all the Intel CPUs which came afterward were guaranteed to have them...

My first "my own purchase" PC was a 486sx. So as a _line_, "the 486" wasn't guaranteed to have an FPU.

I guess that's true. I never really thought of them as the same thing.

Looking over some old info about the "i486" (I swear I had completely forgotten about the i) was a treat. It's only barely believable but I think the sheer annoyingness of Intel's marketing and market segmentation might have actually peaked three decades ago.

The Cray-1 was ~160,000,000 FLOPS. The Apollo Guidance Computer was about 14,000 FLOPS, so about 11,500× slower.

I guess it was THAT much faster. That is an insane leap in performance in a decade. I know they are apples and oranges. One weighed about 150x more than the other, but still such a surprise to me.

Seymour Cray was absolute genius. There are so many innovations in the Cray-1 that you could easily write a book about it.

edit: some searching later:

https://www.goodreads.com/en/book/show/116196

They're not just apples and oranges, but apples vs differential equations. They had completely different requirements. Like ROM being sown for Apollo.

You get something completely different if failure is not an option.

But also yes, it is a big leap. NASA bootstrapped the semiconductor industry by buying up most of the world's supply. Without the Apollo program we may only just now have gotten smartphones. (And some people still think it's a waste of money. pff!)

Yeah, primarily minimize weight and power while meeting compute requirements. Excess compute in this case is bad design.

The cray was 10,000 lb and 115 kilowatts. Not payload friendly.

I'm imagining Kevin Bacon doing his Apollo 13 power budgeting scene, but needs another ~114kw.

Gary Sinise. Kevin Bacon had already had the measles, so he took his place. :-)

> And some people still think it's a waste of money.

Some of those people are right here. The number of times I've seen the 'whitey on the moon' nonsense is quite large.

https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...

And probably most of those people don't realize they wouldn't be posting anything at all if not for 'whitey on the moon', the Apollo program era started with sliderules in 1962 and ended in 1972 with functional microcomputers (8008, 1972, shortly followed by the 6502, 1975) and a very short while later we had programmable pocket calculators (Ti59, 1977). The whole semi conductor industry was jumpstarted in those years.

When I first started out with electronics transistors were an absolute rarity and tubes were normal, in the space of a decade that changed completely.

> NASA bootstrapped the semiconductor industry by buying up most of the world's supply. Without the Apollo program we may only just now have gotten smartphones.

I strongly disagree with that. The semiconductor industry was thriving before NASA even existed, none of the central enabling inventions (MOSFET transistors, semiconductor manufacturing techniques) were made there or even related to the Apollo program, and "computers" as in turing complete machines already existed before NASA and had plenty of applications apart from space travel.

NASA/Apollo giving todays smartphones a 10 year technology boost is just pure fiction and not even remotely supported by facts.

We can't do an A/B with history, but I'm basing it on things like:

> By the mid-1960s, according to the PBS documentary, NASA was buying 60 percent of the integrated circuits produced in the United States. Fairchild was a major supplier, shipping about 100,000 devices for the Apollo space program in 1964 alone.

It's right up there with velcro and teflon.

Not only did the Cray weigh far more than the Apollo computer, and not only did the Cray supercomputer use far more power, but the Apollo computers had to be designed to be highly resistant to interference from radiation.

Radiation hardened electronics are fascinating to me. To this day, electronics that function in outer space are much slower than datacenter or consumer-oriented components.

It is against a Pi 1.

It looks like the Cray gets a bit of a boost from the linpack scores (the pi is only 1.6x faster!), which is a good test for the Cray (understatement!).

Apllo was not the fastest computer in the world. It was a small device enough to shuttle rockets around the moon and back.

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