3 ms·
You are making a terrible apples vs. oranges comparison. A bitcoin hash is about 1900 32-bit integer operations [1]. This is comparable to 1900 32-bit floating
by mrb 13y ago
You are making a terrible apples vs. oranges comparison.
A bitcoin hash is about 1900 32-bit integer operations [1]. This is comparable to 1900 32-bit floating point operations, not one(!). Because most CPU/GPU, when they can execute N integer ops per cycle, can also execute N floating ops per cycle.
So the ratio clearly is in the ~1000 order of magnitude.
[1] https://en.bitcoin.it/wiki/Why_a_GPU_mines_faster_than_a_CPU#Why_are_AMD_GPUs_faster_than_Nvidia_GPUs.3F https://en.bitcoin.it/wiki/Why_a_GPU_mines_faster_than_a_CPU...
- throwaway_yy2Di 13y ago"A bitcoin hash is about 1900 32-bit integer operations [1]. This is comparable to 1900 32-bit floating point operations, not one(!)." That's the amount of work you do in a software implementation of SHA-2, running on a CPU or GPU. This abstracts the hardware complexity inside the chip, which is very relevant when we're going into ASIC's. SHA-2 is bit shifts, masks, and binary adders: it's much simpler than a floating point core. A hardware comparison would be something like ops/(transistor * time). A recent Bitcoin press release [1] claims 500 billion SHA-2 hashes/second out of >1 billion transistors: ~500 hashes/(transistor-second). A 7990 has a peak throughput of 8.2 teraflops SP [2], out of 8.6 billion transistors: ~1,000 flops/(transistor-second). Both are on 28nm processes. [1] http://finance.yahoo.com/news/uniquify-hashfast-announce-working-silicon-160000124.html http://finance.yahoo.com/news/uniquify-hashfast-announce-wor... [2] https://en.wikipedia.org/wiki/Radeon_HD_7000_Series#Southern_Islands_.28HD_7xxx.29_Series https://en.wikipedia.org/wiki/Radeon_HD_7000_Series#Southern...