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Machines

The phone in your pocket outruns the first teraflop supercomputer

By The host3 min#hardware#gpu#webgpu

In 1997 the world's fastest computer drew 850 kilowatts and filled a room to reach one teraflop. Your phone's graphics chip does nearly five, on a battery.

The fastest computer on the planet in 1997 filled a room at a national weapons lab, pulled 850 kilowatts, and needed its own cooling plant. The one in your pocket is quicker.

ASCI Red was the first machine to cross a teraflop, a trillion floating-point operations a second. Intel built it for Sandia National Laboratories, it broke the barrier in a December 1996 run before the full machine was even assembled, and on the June 1997 TOP500 list it sat at number one with 1.068 measured teraflops, almost three times the machine below it.

The record run used 7,264 Pentium Pro processors, the same 200 megahertz chip that shipped in desktop PCs, wired into one enormous mesh. By TOP500's accounting the full machine spread 104 cabinets across about 230 square meters, held 1,212 gigabytes of distributed memory, and stayed on top of the list for seven straight editions. A 1999 upgrade to 9,632 Pentium II OverDrive chips pushed it past three peak teraflops. The sticker price is the one number I went looking for and could not pin down.

Your phone clears all of it. The spec tables disagree on the exact figure for the Adreno GPU inside a 2024 Snapdragon 8 Gen 3, from roughly 4.7 teraflops at the cautious end to 6.1 at the listed peak. Take the low number and the phone chip is still more than four ASCI Reds, running on a battery, in a jacket pocket.

So the supercomputer a country built to simulate nuclear weapons is now a rounding error against the thing you use to answer texts. That is the receipt, and it should feel stranger than it does.

Where the teraflops hide

A phone's real muscle is the GPU. That Adreno packs 1,536 single-precision units running the same arithmetic across thousands of numbers at once, which is the exact shape of a graphics frame and, as it turns out, of most machine learning. ASCI Red bought its teraflop with thousands of general-purpose CPUs and a building. The phone gets several from one sliver of silicon by refusing to be general.

The old catch was reach. Only a native app could touch that hardware, and a web page got a slow, polite fraction of it. That wall came down in May 2023, when Chrome shipped WebGPU in version 113. A browser tab can now hand raw compute jobs straight to those GPU cores, compute shaders writing into storage buffers, no game engine in the way. Google's launch post claimed better than threefold speedups on machine-learning inference over the WebGL workarounds it replaces.

Pair that with WebAssembly, which already boots a whole Debian Linux in a tab, and the browser stops being a document viewer that also does sums. It becomes a way to aim the entire chip at a problem. The fluid simulation that solves Navier-Stokes in a fragment shader managed its magic through WebGL's narrow keyhole; WebGPU takes the door off its hinges.

The gap is the part that gets me. You are carrying more parallel compute than the 1997 nuclear weapons program, behind a sheet of glass, and most of it spends the day holding a text field steady while you type.

If you want to point yours at something, WebGPU Fundamentals starts at a blank page and works its way up to compute shaders. Open a demo and listen to the fans that are not there stay quiet.

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