When GPU mining Litecoin became a reality, people kept spreading FUD that ArtForz and/or I have been GPU-mining Litecoin from the start.

Let me put this issue about GPU-mining from the start to rest once and for all.

I will use cumulative difficulty to figure out how much hashpower has been working on a chain since the start.

There's going to be a lot of math here. First read up on this:

https://en.bitcoin.it/wiki/Difficulty#What_network_hash_rate_results_in_a_given_difficulty.3Fhttps://github.com/litecoin-project/litecoin/wiki/Mining-hardware-comparisonHere are the current state of things:

Current difficulty: 20.794

Number of hashes to solve a block: DIFFICULTY*pow(2,32) = 89,309,034,556.95

Seconds per block: 2.5 * 60 = 150s

Theoretical network hashrate (in mhash/s): DIFFICULTY*pow(2,32)/pow(10,6)/SECONDS_PER_BLOCK = 595 mhash/s (~2000 average GPUs)

Litecoin was launched on 10/13/2011 03:00:00 at block #3:

http://explorer.litecoin.net/block/dec173dda2735ff11376b68bdfda804cede230c1fa6f1a11765cddfd8edf4398We can calculate how much hashpower has been put on the chain since the start using cumulative difficulty.

Let's check a recent block 294537 found on 2/12/2012 03:00:00

http://explorer.litecoin.net/block/a065026ba50a71e1d4979e078265dc9ccf15d0b393969cd35ec4c954bf2c22fbYou can see the cumulative difficulty on the block explorer page.

Cumulative difficulty: 2,421,540.599

Number of hashes: DIFFICULTY*pow(2,32) = 10,400,437,678,641,250

Time since start (in seconds): 2013-02-12 - 2011-10-13 = 488 days * 24*60*60 = 42,163,200 s

Theoretical network hashrate (in mhash/s): DIFFICULTY*pow(2,32)/pow(10,6)/TIME_SINCE_START = 246.67 mhash/s (~1000 average GPUs)

So we average about 1000 GPUs working on the chain. In other words, if you had 246.67 mhash/s pointed at the chain since launch, you'd have found just as many hashes.

Now, here's what you all wanted to know. How much hashing power was pointed at the chain during the first week.

Here's block 14807 found at 10/20/2011 03:00:00:

http://explorer.litecoin.net/block/6fcf032b2edfd3e06ee6cace9ed9b6c219d8dca06fa1f43a47cb1c5b7f87084fLet's do the same math:

Cumulative difficulty: 438.193

Number of hashes: DIFFICULTY*pow(2,32) = 1,882,024,604,336

Time since start (in seconds): 7 days * 24*60*60 = 604,800 s

Theoretical network hashrate (in mhash/s): DIFFICULTY*pow(2,32)/pow(10,6)/TIME_SINCE_START = 3.11 mhash/s (~100 average CPUs OR 10 average GPUs)

A month later. Block 31011:

http://explorer.litecoin.net/block/7b08a3bfb5f2a865fc0061f6e3f5b97fa1690c8d357ccd814fd9f55641f83187Cumulative difficulty: 5,949.565

Number of hashes: DIFFICULTY*pow(2,32) = 25,553,187,100,426

Time since start (in seconds): 31 days * 24*60*60 = 2,678,400 s

Theoretical network hashrate (in mhash/s): DIFFICULTY*pow(2,32)/pow(10,6)/TIME_SINCE_START = 9.54 mhash/s (~300 average CPUs OR 30 average GPUs)

After 3 months (

http://explorer.litecoin.net/block/55d1323fa4d7175953fab43ef97c0ef18577d8f000e494740ccc867d42fe67f5), average hashrate is 18 mhash/s. You can do that math yourself.

Seems like the normal growth of a CPU-only (at the time) coin to me.

ArtForz had 24 5970s. 5970s can do 750 khash/s. If he put those 5970s on mining Litecoin, he would have 18 mhash/s, which is twice the work done on the chain in the first month. Litecoin was put on the exchange pretty quickly and mining litecoins was pretty profitable even with a CPU. If ArtForz had GPU scrypt mining from the start, would he not put those machines on mining Litecoin and make a killing?