One-Sentence Definition
Equihash is a memory-intensive proof-of-work mining algorithm that requires lots of RAM to solve, originally designed to make ASIC mining difficult and keep mining accessible to GPU miners.
Why It Matters for Solo Mining
For solo miners, Equihash mining means you can compete with reasonable GPU hardware without getting completely dominated by specialized ASICs like you would mining Bitcoin. The algorithm’s memory requirements make it expensive to build ASICs for, which levels the playing field a bit. However, the high variance of solo mining still means you might wait months or years between blocks depending on your hashrate.
How It Works
Equihash is based on something called the “Generalized Birthday Problem” — basically a math puzzle that requires lots of memory lookups to solve efficiently. When you’re equihash mining, your GPU spends most of its time reading and writing data to RAM rather than just doing raw calculations. Different versions exist with different parameters (like Equihash 144,5 or 200,9) that change how much memory you need and how fast mining goes.
The algorithm was specifically designed to be “ASIC-resistant” by making memory the bottleneck instead of processing power. Since RAM is expensive and hard to optimize, building a specialized mining chip doesn’t give you as huge an advantage as it does with other algorithms. The idea was to keep mining decentralized by letting regular people with gaming PCs participate.
Most Equihash coins require between 1GB to 3GB of GPU memory depending on the specific variant. Your mining software solves these memory puzzles millions of times per second, and each valid solution can potentially win you a block if you’re lottery mining.
Example
Zcash is probably the most famous Equihash coin — it uses the 200,9 variant which needs about 2.5GB of GPU memory. If you pointed an NVIDIA RTX 3070 at Zcash solo mining, you’d get around 62 Sol/s (solutions per second). With the current network difficulty, your expected time to block would be several years, but hey, someone’s gotta win eventually!
Think of it like a massive memory matching game where you need to flip through thousands of cards in your RAM to find pairs that match specific rules — GPUs are good at this because they have fast memory and can check many combinations simultaneously.
Related Terms
- Ethash / Etchash — Another memory-hard algorithm with different design goals
- DAG Size — Similar concept of memory requirements limiting mining hardware
- GPU Mining — The type of hardware Equihash was designed for
- ASIC — The specialized hardware Equihash tries to resist
- Solo Pool — Where many Equihash solo miners point their GPUs