I have a question, what are these computers actually computing that you need a warehouse full of them?
They are mining money. You don't "need" a warehouse full of them. Each miner consumes electricity, produces a lot of heat that must be mitigated and produces a small daily revenue. Here are some rough numbers but remember they vary depending upon many factors including the cost of electricity and the current value of the "coin" you are mining. These numbers are from Compass Mining. They sell miners and miner hosting where you buy the machine and they set it up and run it for you. The newest ASICS Ant Miners are going for around $10,000 to15,000 if you can find one. The price of miners moves with the value of Bitcoin. The newest Antminer will typically earn just under $30 a day. Subtract your $8 (depends on how much you pay for electricity) of direct power consumption and your left with $22 a day. That means if your miner is up and running 24/7 it could take you up to 681 days to recoup your investment. Miners do need maintenance, cleaning and repairs and down time can be significant. The reason you hear about warehouses full of miners is that it is a scalable business. Several of these mega miners are in Texas because of its cheap cost of electricity. The less you pay per KW the more profit you make. There are over a dozen publicly traded bitcoin mining companies. One has a market cap of 791M. These companies raise money, buy miners, run the mining operation but aren't selling their BTC. They instead hold them and borrow against them to run their businesses. Riot, for instance, spent $651 million to acquire mining assets in Rockdale and plans to spend
$160 million on the infrastructure build out. Marathon recently raised $650 million. The big players are dominating the market and make it hard for an individual to make money. Last year Marathon ordered 70,000 new miners. That kind of makes it hard for an individual to buy one.
Copy/pasted from Compass:
"Bitcoin mining is the process of recording transactions on the Bitcoin network. To do this, miners compete against each other to solve a difficult puzzle that resets every 10 minutes. Winning miners are awarded a predetermined amount of bitcoin for their success after each interval.
Miners provide a service.
Miners add batches of transactions to the blockchain, which is akin to making entries in an accounting ledger anyone can look at. These transactions have been verified by other network participants and sit in a holding depot of sorts called a memory pool (or “mempool”). From the mempool, miners take transactions and package them in blocks.
Mining is the process of adding those blocks to the chain. For this service, miners are paid a fee for each transaction and a set reward for creating the next block in the chain.
Read: How do miners make money?
Mining is a hashing race.
The technical details of bitcoin mining are extensive, but at its most basic elements, mining is a race to reveal encrypted data. The data hidden in the puzzle miners need to learn is a randomly generated string of numbers called a nonce.
Each block’s nonce is encrypted as a hash, or an algorithmically generated string of letters and numbers that is impossible to decode. Mining is a game built around guessing what the unknown nonce is, and the rules are simple: be the first miner to guess correctly.
Learn more about nonces.
Because miners cannot simply “unlock” the hash to learn the nonce, they must generate random nonces of their own, hash them, and compare their hashes to the unknown nonce’s hash.
Finding a matching hash to a block’s public one means the miner has also generated an identical hash. When matching hashes are generated, the new block is added to the blockchain and the winning miner claims their reward. So, to earn bitcoins, miners make new guesses at the encrypted nonce over and over as fast as possible.
Bitcoin’s
hashrate serves as an estimate of how much computational activity is spent on this game."