It sounds like this is just some GPU owners wanting to turn back time to protect their assets.
False. Mining difficulty automatically adjusts to compensate for faster hardware. Nothing is gained.
Increased efficiency is generally beneficial in non-zero-sum games, but cryptocurrency mining is actually a zero-sum game where increased efficiency does not add value anywhere.
Well, where's the gain from mandating GPUs?
> increased efficiency does not add value anywhere
Back to CPUs, then?
That means a stark concentration of mining power, because it means "average joe shmoe" can't just start running cgminer on their integrated openCL hardware and get coins at reasonable rates for the money invested (in power).
I think it is too late for litecoin, and would rather see them implement this in a less entrenched altcoin like peercoin, because there is too much inertia and scale now to change it in the litecoin space.
GPUs may be ubiquitous but it's not viable to run a mining rig with just one, which means that all those GPU miners are basically running "specialised hardware" too. Joe schmoe does not just happen to have an 8-GPU tower computer lying around.
It's not totally vanilla hardware like the 15-watt laptop I'm typing this on, but it is common enough I happened to have it already.
With ASICs the barrier to entry is five figures. (Most of the cheaper ASICs have terrible payoff timelines) With GPUs the barrier to entry is far, far lower. You won't make it rich on a $150 GFX card, but you can make some revenue.
ASIC resistant
GPU resistant
botnet resistant
My Cuckoo Cycle PoW (https://github.com/tromp/cuckoo) configured to require for instance 7GB of memory, is all of the above. And is very power friendly, since only 5% of the runtime is computation and 95% is waiting for main memory random access latency...
Sure, if you can come up with a good proof-of-work algorithm that runs well only on CPUs.
It could be possible. The straightforward way would be, I believe, to use an algorithm that has weak parallelism and depends strongly on branching. CPUs are king of branching, and both GPUs and ASICs get ahead by taking advantage of parallelism.
Although, one nice thing about GPUs being the standard-bearer, is it makes most general purpose server hardware useless for mining. That's good in that it makes hijacking a webserver to mine bitcoins, a largely pointless affair.
Also, don't fool yourself on power efficiency. The network adjusts the difficulty, so if ASICS are 100x as power efficient the difficulty will tend towards 100x harder.
And yes, it's always a balancing act. The network adjusts the difficulty based on total hashrate, not on power efficiency, which is just an overhead. More and more people will pile in until the difficulty is high enough to render mining unviable. However, ASICs at least will shift the balance more towards hardware costs vs the raw power cost that it is now, and reduce the number of useless components that need to be manufactured, etc.
Everyone has a GPU, and your gpu is usually on the same magnitude of efficiency (assuming its modern) as the optimal GPU miner for any given algorithm. With ASICs, the barrier to entry is huge, so you have less "casual" miners. The casual miners significantly dilute the power of concentrated mining operations.
i wonder if there is a solution to the byzantine general's problem with that is resistant to 50% malicious nodes but doesn't require so much energy overhead. even proof-of-stake coins still require energy wasting.
As compared to entire blocks of office high-rises in every major city required for our current financial system?
Though it is worth mentioning there are cryptocurrencies looking to solve this problem, like peercoin's proof of stake.
I somehow suspect, however, the proponents of this change are not "regular joes", who might have an intel HD2000 in their laptop. And if we're going to play the "democratising" card, with GPU mining it's a lottery of where you happen to live - electricity prices vary wildly around the globe. ASICs help to take that out of the equation, so if anything they're more "democratic"!