Same public idea, different chain, no relationship between the projects.
Stated plainly: SolMix has no affiliation with Tornado Cash, shares no code and no people with it, and inherits none of its history. What the two have in common is a design — a fixed-denomination pool with zero-knowledge withdrawals — that is public and has been implemented independently many times over. That is the whole of the overlap.
Fixed denominations, so deposits are interchangeable. A commitment appended to a Merkle tree. A proof of membership standing in for a receipt. A nullifier recorded to prevent a second spend. A relayer so a fresh wallet does not have to be funded first. Any honest implementation looks like this, because this is what the design is.
| Ethereum pools | Here | |
|---|---|---|
| settlement | minutes, and variable | seconds |
| cost per note | gas-dependent; historically dollars to tens of dollars | ~0.001 SOL, flat |
| verification | EVM precompiles | BN254 syscall, ~110k compute units |
| dominant cost | gas at the moment you transact | permanent nullifier rent, paid once |
The flat, low cost is the difference you actually feel. On Ethereum at a bad moment, mixing a small amount could cost more than the amount was worth. Here the charge is identical whichever pool you use, which turns choosing a pool into a privacy decision instead of a budget one.
The pool, the crowd, the reputation and the legal history. These pools began empty and are exactly as deep as they are today — a number printed on the picker, not borrowed from anybody else. Any service implying it starts out with someone else's anonymity set is misleading you about the only figure that matters.