CPU vs GPU vs ASIC: Why Your PC Can’t Compete
| Hardware | SHA-256 rate | Share of network | Sats / day | $ / day gross |
|---|---|---|---|---|
| Desktop CPU (generous) | ~50 MH/s | 1 in 20 trillion | 0.002 | $0.000002 |
| Gaming GPU (generous*) | ~10 GH/s | 1 in 102 billion | 0.44 | $0.0004 |
| Bitaxe | 1.2 TH/s | 1 in 851 million | 53 | $0.04 |
| Antminer S21 | 200 TH/s | 1 in 5.1 million | 8,811 | $7.40 |
Rate = hashes per second. Sats are satoshis — 100,000,000 sats = 1 bitcoin. Block subsidy (3.125 BTC × 144 blocks/day) only — fees excluded. *No maintained Bitcoin GPU miner exists; the GPU row is a generous ceiling derived from crypto benchmarks. Static figures dated 2026-09-25; live values replace them at load.
The arms race, in four steps
CPU, 2009. Satoshi's laptop era — a processor that can run anything, pulling a few million drawers a second (MH/s — mega = million).
GPU, 2010. Graphics cards run thousands of small math jobs in parallel — hundreds of MH/s per card. The CPU era was over within a year.
FPGA, 2011–12. A brief cameo: chips you rewire in software — GPU-class speed at a fraction of the power.
ASIC, January 2013. Canaan's Avalon1 shipped: 60 GH/s at ~600 W, sold for $1,299. The whole network was ~20 TH/s then — one machine was roughly 0.3% of it. Each step beat the last by 10× to 100×, and difficulty rose automatically to match — which is the polite way of saying each step made the previous hardware scrap. Today's S21 does 200 TH/s — roughly 3,300× the Avalon1's speed on about a 570th of the energy per hash.
Why a one-trick chip wins
A CPU spends most of its silicon on flexibility — it must run anything. A GPU spends it on parallel-but-still-general math. An ASIC (application-specific integrated circuit — glossary) has Bitcoin's one calculation physically etched into the chip, copied thousands of times, with nothing else on the silicon. Nothing wasted on could-do: a chip that does nothing but pull drawers. The efficiency ladder tells it plainly: to pull the same trillion drawers (one terahash), a desktop CPU burns roughly 2,000,000 joules, a GPU roughly 30,000 — an S21, 17.5. That's about a hundred-thousand-fold energy gap per unit of work, and electricity is the whole cost of mining.
Why does an ASIC pull drawers so much faster than the CPU in your PC?
The catch: one trick is all it does
The day SHA-256 mining stops paying its power bill, an ASIC has no second career — it can't game, render, or run a spreadsheet. A GPU keeps its day job and its resale value; a retired ASIC is a heater with a fan. That single-purpose scrap risk is the honest price of the speed, and it's priced into every used-market listing you'll ever browse.
But people DID mine with GPUs, right?
Absolutely — just not Bitcoin, not for long. After 2011, GPU miners moved to other algorithms: Litecoin-style scrypt coins until scrypt got its own ASICs around 2014 (that lane's story), then above all Ethereum — which carried the overwhelming majority of GPU mining revenue until it switched off proof-of-work entirely on September 15, 2022. What's left today is small coins at margins that rarely clear a household power bill. And services that pay you BTC for your GPU's work on other algorithms are selling your hashpower, not mining Bitcoin.
So what do you actually do?
The answer-box number — $0.0004/day — settles the PC question. If the itch persists anyway, the honest path is a small real ASIC like the Bitaxe, and lesson 4 already computed what home mining actually looks like. To run any hashrate and power price against the live network yourself: the mining calculator.
You point your gaming PC at Bitcoin tonight. What actually happens?
A service offers to pay your gaming GPU in bitcoin. So GPU-mining Bitcoin still pays?
A used ASIC is listed dirt cheap because its algorithm no longer pays the power bill. What is that machine worth to you?
FAQ
- Can I mine Bitcoin with a regular PC?
- Technically yes — the software runs on anything. Economically no: a gaming GPU's slice is roughly a billionth of a percent of the network, fractions of a cent a day against a real power bill. The table above computes it live.
- Why do you need an ASIC to mine Bitcoin?
- The competition uses them, and difficulty rises to match the competition. An ASIC etches the hash function into silicon and does nothing else; once they took over in 2013, general-purpose hardware's share fell to effectively zero. Arithmetic, not a rule.
- What happened to GPU mining?
- Left Bitcoin around 2011 for other coins; scrypt went ASIC-only around 2014, and Ethereum ended proof-of-work in September 2022. What remains rarely clears a household power bill.
- If ASICs always win, what's the catch?
- One job, forever. When its algorithm stops paying, an ASIC has no second career — a GPU keeps its resale value; a retired ASIC is a heater with a fan.