A universe is a time budget, not a channel count.

DMX512 is a serial line at 250 kbit/s. Every slot is one start bit, eight data bits and two stop bits — eleven bits, 44 µs — and a packet is a 92 µs break, a 12 µs mark after break, a start-code slot and then up to 512 data slots. That is 22.68 ms, which is 44.1 Hz, and it is the ceiling on every fade, every move and every strobe step in the rig.

The engine is free and needs no account. And you pay for the slots you send, not the ones you use: stop the packet at 128 slots and the same wire runs at 173 Hz — 3.92x — but most consoles and nodes send all 512 whatever is patched, so a rig using a quarter of a universe is updated at the full-universe rate for nothing. Sixteen bits buys resolution, not smoothness: a fade can only change at a packet boundary, so a 3 s fade gets 132 moments — and 65,536 values across 132 moments means stepping 495 values at a time, against 1.93 for eight bits. The mode is the cost: the same LED par is 4 slots in one mode and 12 in another, which is 128 fixtures a universe against 42. And dividing is not the method — a fixture needs contiguous slots inside one universe, so 64 fixtures at 24 slots divides into 3 universes and really needs 4, because the 8 stranded slots per universe add up where division cannot see them. Every lane ships a worked example that costs nothing. Writing the report needs credits.