Post
Topic
Board Bitcoin Discussion
Re: Bitcoin puzzle transaction ~32 BTC prize to who solves it
by
krems_hive
on 14/08/2025, 15:24:24 UTC
Wanted to ask, given the latest puzzle and last couple of solved puzzles are unprofitable to crack by renting from, say vast.ai or clore.ai, what do you guys think these people who cracked last couple of puzzles rented those 1000s of GPUs?

Current prices say they should spend around 1.5 million usd to crack 6.9 btc puzzle which is not at all profitable. So, how are they doing it? Stolen/hacked GPU compute?

Large scale GPU grids over long-term contracts, possibly interruptible instances for an even cheaper price. And obviously, very fast software and a bullet-proof distributed communication system to sync work.

If you think the puzzles are solvable by clicking "Rent" buttons and uploading some binaries to print BS on the terminal shell, too bad.

I agree 100%. But I have checked 10s of websites and cheapest ones are vast.ai interruptible ones. And you can't rent more than 200 GPUs without price going up massively. Using that as benchmark I got 1.5 mil price tag.

It will take 5k 4090 GPUs * 114 days (total of 13.7m gpu hrs) to solve 69 puzzle which is 2^68 keys of work.

At cheap prices of 0.1 usd/gpu/hr it costs 1.37m usd.

Based on info from chatgpt, even for datacenters running at 2 cents/kwh and 5 year depreciation on hardware - it costs 800k. Which barely breaks even.

We should also note that this particular puzzle 69, the key was unusually beginning of the search space which is an absolute win if the cracker was working on batches sequentially.

In any case, puzzle 68 was profitable for data centers and break even for bulk renters.
Puzzle 69 is break even for data centers.

So, puzzle 71 (which is 4x harder and resource intensive than 69) in theory should be uncrackable. Unless you have compromised a whole data center and stealing their 1000s of GPU compute resources and they didn't notice for months.

What are your thoughts on this?