Inside a Bitcoin miner

Every bitcoin block is found by chips like this one, each guessing about a trillion times a second. Take one apart, then watch a single hash core work through real block headers, slowed down far enough to see.

From hashboard to hash core

Drag to orbit

One hashboard

An S21-class miner holds three of these boards, each carrying dozens of identical chips under a heatsink (left off here). Every chip runs the pipeline this page shows, around the clock.

The simulation

One hash core

A mining chip tiles many of these side by side. Each one is a 128-stage conveyor: a nonce enters on the left, is mixed through 64 rounds of SHA-256, then 64 more, and falls out the end as a hash. Every stage is busy on every clock, so one finished hash exits per tick, and it's checked and thrown away as soon as it arrives.

How this page works

  • The headers are the real 80-byte headers of blocks 968,395 and 968,396, the newest blocks with a confirmation when this page was last updated (2026-09-24); they're refreshed from mempool.space every day. Every hash on this page is computed in your browser, one SHA-256 round at a time, and the winning nonces reproduce the real block hashes.
  • The clock is an assumption: 500 MHz, with a fully pipelined core finishing one double-SHA-256 per clock. Real chips differ in clock speed, core count and pipeline layout. The time-dilation figures scale with this number.
  • Real chips cut work further. Rounds 1–3 of pass 1 don't depend on the nonce, so they're computed once per job. The hash's top 32 bits are already fixed after round 61 of pass 2, so many designs check there and skip the last three rounds.
  • Miners also roll version bits inside the BIP 320 range (0x1fffe000), which changes block 1 and so the midstate. Both of these blocks did. This page keeps the version fixed.
  • The ~50-bit real share target is an estimate: an S21 at 234 TH/s submitting roughly one share every 5 seconds does about 2⁵⁰ hashes per share. The 8-bit share target here is only so you can see shares happen.
  • Replay sets the counter 103 nonces before the real winning nonce. Every hash along the way is a real attempt on the real template, but the original miner didn't necessarily try those exact neighbours.
  • The 3D model follows flip-chip packaging, which teardown analysis shows recent Bitmain chips use (TechInsights on the BM1366). Bitmain publishes no datasheets, so dimensions, bump and ball counts, the board layout and the number of chips shown are illustrative. The heatsink that normally covers the chips is left off.
  • The silicon view is a representative layout drawn from the logic, not traced from a real chip. What is real for every stage: which flip-flops exist, the bit each one holds, which bits flip on each clock, the switching activity of each logic block, and the K constant wired into it. Placement, proportions, core count and the die periphery are illustrative, and only the outlined core's glow comes from the simulation.
  • Sound is off by default and synthesized in your browser; nothing is a recording. The fan is the same model as the Hashweight panel's. Everything after that comes from the simulation: a tick for every clock, a tone for every hash whose pitch comes from that hash's last bits, a chime for every share, and a hiss that follows the switching activity.

See what all of these machines weigh together in Hashweight, or how the rest of the site works on the methodology page.