Bring back GPU miners?

Ok, ok, I know this could set off a firestorm of debates (again) but let me first say I’m not buying or selling the idea of ASIC resistance, it was brought up on Twitter by a former Zcash core developer the other day and I thought they had an interesting perspective.

When Zcash first launched it chose the Equihash mining algorithm to be ASIC resistant (an assumption that turned out to be wrong)
to better democratize Zcash distribution among more parties. There was a window when Zcash could have forked to avoid the new ASICs but the community/ZF/ECC chose not to

So here we are, years since the introduction of ASICs. With history behind us was doing nothing the right decision?

Also, please note that I am a full supporter of Zcashs move to PoS, as soon as possible, it is the most energy efficient long term option, but realistically, how far in the future is our move to PoS? I’m guessing it won’t be ready by this October halving (please correct me if I’m wrong).

So sometime before then, or perhaps at NU6, could be a chance to make a mining algorithm change until PoS is ready.

With PoS on the near horizon, why consider an algorithm change at all? I think it’s an interesting idea for a few reasons:


  1. It should not be too difficult/time/resource intensive to implement an already proven algorithm (like Ethash).
  2. It could be a way to get an influx of new (and bring back old) users who would be excited about mining and using Zcash.
  3. It would disrupt Zcash ASIC farms. Some that only mine ZEC to dump it for BTC or some other coin.
  4. It could give GPU miners a chance to stack ZEC in preparation for the upcoming switch to PoS.
  5. Tons of former ETH miners already familiar with Ethash could ensure that there would readily available mining hardware to support Zcash during a switch.


  1. Hard fork required, risk to network stability.
  2. 50% attack risk if not enough miners/pools are ready/willing to mine Zcash.
  3. Would require some time/resources to implement on Zcashd and Zebra. Development time that could be better spent elsewhere, like prototyping PoS.

Last point:

“But why Ethash if its not truly ASIC resistant?”

The difference of Ethash on an ASIC vs a GPU is only about 3x:

RTX3090 = 130Mh/s - 300w = .41 Mh/watt
Antminer E9 = 2400Mh/s - 1920w = 1.25 Mh/watt

Compare that to Zcash today:

RTX3090: 72Sols - 300w = .21 Sol/watt
Antminer Z11: 135,000Sols - 1418w = 95.7 Sol/watt

A switch the Ethash algo essentially means that Zcash would not become more ASIC resistant, but would become more GPU friendly.


So there you have it, a few ideas that have been bouncing around my head I had to get on digital paper since Zeboot is coming up early next year. I sincerely apologize in advance :sweat_smile:


I came in when ASIC mining was already a thing. It always troubled me. Given the issue we have with one single pool having the most hash power and ZEC being dumped at cost price this would be worth exploring


I’m actually more worried about the second point Gabizon brings up in that tweet, which is that Zcash is not being capable of building a legacy within its core development


While I agree that the loss of GPU mining has done a lot of damage to Zcash and it’s hard to argue with that, I also think that absolutely any sudden change of anything is always a very dangerous topic. It’s not like a well-planned strategy, it’s like panicked tossing from side to side as if trying to stop an imminent collapse. That’s why such a crude intervention is always damaging to the image in the first place. This was when the option to change the algorithm to prevent ASICs from developing was abandoned, it will happen now. At first GPU miners received information in popular media that Zcash will resist ASICs and the huge community of miners took this news very positively and enthusiastically. But just a few months later, the exact opposite information was published. I remember it very well. It looked like some kind of backroom deal with the hardware manufacturers. And since GPU miners still haven’t forgiven that decision, believe me I know what I’m talking about, it’s not a fact that we’re can to attract GPU miners today. But the fact is that people who bought ASICs to mine ZECs will be totally pissed off. Plus obviously a 51% attack is going to be very much more likely. I am against such things today, when Zcash’s image needs to be protected more than ever.


Excellent and timely post.

I believe the decision to alienate GPU miners long ago did great harm to the community inclusive approach Zcash initially launched. At its inception, Zcash had a large, enthusiastic community of participants who reveled in the fact they too could successfully participate in mining. We lost many supporters to Monero over this strategic decision not to fork and as a result the size of our community plummeted. This was a mistake.

I think we can all agree Zcash requires more participants in a wider community. If this could help without significant risk, I would be supportive.


Very good points @artkor . Perhaps the trust already lost is not recoverable.

Curious if there is any data about how many independent miners are still running Zcash ASICs in this market? Seems that all of them are very unprofitable unless you have the biggest version (Z15 pro) making about $.15 per day.


Even though it’s not directly related to this topic, although indirectly yes… But we know what we’re talking about. We are talking about the part of pricing called supply. On the forum we talk a lot about how to increase demand for ZEC. But there’s not much to say about supply. The fact is that most likely all 100% (or close to it) of ZEC issuance today is going straight into the market. Most ASIC miners are exchanging it for Bitcoin. And I’m not going to argue with that anymore today, because it’s a completely obvious decision after covering the power costs. Bitcoin is more stable in price, Bitcoin is scarcer, so the ZEC/BTC trend is linear and predictable. What’s the point of going against the trend?

Development funds also have to provide key activities, we are not going anywhere from this. And alas, the lower the price of ZEC, the greater the volume of coins goes into realization. During these periods, it is possible that funds spend more than they receive.

The key idea of this topic is very clear. We assume that the percentage of GPU miners selling an asset is much lower than the percentage of ASIC miners selling an asset. This is also my point of view. This way we are technically reducing the supply of coins on the market and influencing the pricing in a better way for us.

Okay, then my suggestion is that we move as soon as possible already to PoS and focus as much as possible on doing it right this year. Make it task number one. What I mean by that is that current ZEC holders today are already so strong that they remain calm even on rumors of delisting from the largest exchange on the planet and they will not sell ZEC from PoS like ASIC miners do.

Coupled with the upcoming halving, this has the potential to create a shocking shortage of supply of coins on the market overnight. This all easily counts. It needs to be done during a bull market period, the start of which presumably coincides with the halving. Such a deficit will boost the price and attract investment demand, which will create a price upward spiral. And then our esteemed funds will have enough money to realize all the wonderful ideas that stimulate the natural demand for the Zcash network and the use of ZEC. Bingo!

@nathan-at-least @joshs


100%. This is an excellent post @artkor.

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Agree on this point.

This was my first thought, however with only about 11 months to go until the Halving, we still have a mountain of work to figure out.

  1. Zcashd → Zebra codebase?
  2. Are we going to have a new dev fund? (Y/N What’s the structure?)
  3. ZF is working on FROST
  4. ZF is working on Zebra
  5. ECC is figuring out Trailing Finality Layer
  6. ECC is still in prototype stage for PoS research/prototype. (What’s coin issuance look like? Algorithm?)
  7. ECC is working on Zashi SDK
  8. QEDIT ZSAs work should also still be considered

Which is why I said I don’t think there is enough time to get to Zcash to PoS by October. I also don’t think there’s time to get ZSAs by then. A mining algo change may be containable but risky.

So the question is what can be contained by then?

All of this is hopefully things that will be discussed in January Zeboot. @joshs and @Dodger certainly have their hands full :slightly_smiling_face:


Absolutely. We have many plans and at the Zeboot need to pick key areas that will lead us to success. I wrote this as my suggestion because I am categorically convinced that the future success of the project will depend entirely on the price context of ZEC. I am convinced that ZCAP members will once again vote in favor of allocating development funds. There will be some acceptable option, but let’s face it, Zcashers have already endured for a very long time, and themselves go through this unfair reality, in which the project with the most science-intensive background consistently has a negative ROI. That said, there is an obvious solution that will solve this problem. Let it be PoS v.1.0 such that it provides the minimum required level of security and resilience, let it not be the coolest in the world. On this forum we can type in the search phrase “the best is the enemy of the good” because it has been heard here many times. While we are doing the best, other projects are leaping into the bright future. And as we know, not everything is perfect. For example, BOSL license for Orchard ceased to exist before Orchard got the SDK for wallets. So? No one even realized the irony except a small number of people. It’s the same here. Let’s emphasize the right things that will work 100% for the good of Zcash and for the good of the people who have been supporting it for years.






@artkor and @Shawn you guys make a compelling argument to change the algo, I have a couple of concerns though:

  1. making zcash GPU makes it very susceptible to 51% attack, with a marketcap of only $460MM, we would not be able to attract enough hash power to make it too expensive to attack. Even within Ethash itself ETC dwarfs ZEC at 3 billion MC

  2. The upcoming halving has a real risk of leaving the project without enough capital to operate as is, ECC is already under financial pressure. This is an unpopular opinion, but ZEC dominates the equihash algo by about 80% of the hash rate, so that actually leaves us with options to adjust the mining rewards to direct more funding to the project and remain safe from a network attack

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we need to stop all non development spending which will reduce the cash burn and alleviate the funding concern. they should be cutting and building cash. so that means no education and no marketing and anything else that is deemed non core until ZSAs/stablecoins are done, sync times improved, and we move to POS. we don’t have anything to educate anyone about. we need to get real and see no one uses ZEC as expected or as it’s marketed/advertised. People should be buying ZEC to hold until we can stake against ZSA/stablecoin transactions. @Shawn has a very good suggestion to help bridge to POS. I’d also like to see all the orgs coordinate resources to make sure we get there. the privacey is everything mantra is very hollow without other critical attributes. the world has to passed this s by and now we need to catch up…so we need to move and improve beyond privacey: ZSA/stsblecoins, collateral, speed, POS as key areas.


Unfortunately, with things as they sit right now one pool ViaBTC has over 55% network hashrate for awhile, on and off.

I don’t have empirical data if this situation would be better or worse if we were to switch to Ethash. The more I think about it, maybe a change is a way to rectify this pool holding 50+% of the hashrate ? :thinking:

I’m not sure there is a direct correlation between Zcash being the biggest Equihash hashrate mined coin and the possibility of a new dev fund. It is still being debated if there will be one, and if the community votes in favor of some sort of self funded mechanism then core teams can publish the code with what the community supported.

For reference of how consensus was reached last time: Reaching Consensus - Electric Coin Company Also of note is that last time the large mining pools were invited to participate in the Zcash governance process but chose not to.

If for some reason a portion of miners decided not to follow a network update published by the core team then they can choose to fork Zcashs open source code and publish their own version which won’t be supported by the core teams. They would then need to rename their version “something other than Zcash” because Zcash Foundation still has the Zcash trademark.

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The connection is between hashrate and miner profitably, theoretically if more of the mining reward is allocated to the dev fund, you would expect a decline in hash rate to keep profitability constant.
Hence there is capacity to alter the funding model to skew more to development because Zec has such a large margin as being the leader in equihash.

Anyway before this thread strays too far from the intention, the point I am making is everything is linked and changing the algo could have unforseen consquences, sometimes its better the devil you know

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Agree :100: this is one of the many things I love about the Zcash community: intelligent debate and differing opinions to try to find the best outcome!


Being the dominant chain in an algo is the safest place to be.

When eth was still pow, etc had to come up with creative ways to prevent 51% attacks. Mess is finally about to be set as non-default.

Ethereum classic switched to etchash a few years back which removed the dag and allowed all gpus to mine because GPUs are less efficient asics with slightly better decentrilization when they are in a mining farm. We considered switching to ProgPow, a tuneable version of ethhash, when the desire was to keep asics frustrated.


In my opinion it is a mistake to assume that there is a 51%-attack in ASIC mining.

There may be one pool with a full hashrate of 100%, but it has no motivation to hit the network at a loss to itself. The key is that the hashrate is so high that no one from the outside can launch an attack.
No one from the outside is able to rent as much power as needed to attack an ASIC network at one time. This was the motivation for not resisting ASICs and nothing has changed since then.

The only possible loss here is reputational, nothing more. Because the media will talk about it, and most people don’t know what it’s all about and will think that the network is threatened by something.

Conversely, we can have a super dispersed GPU network in solo but with a low hashrate. And then the attack will be launched suddenly via leased power on Nicehash.

From a security point of view, what we have now is a much better solution than what we can get from risky steps.


Philosophically, I rather disagree. I would prefer Zcash to have an image and ethos of continuous iterative improvement, ready and unafraid to make granular tweaks and upgrades as new information comes in.

Yes, change the parameters and bring back hobby mining.

Also, tangentially related: aggressively deprecate old tech debt and get rid of it asap (sprout, zcashd, old bitcoin cruft, chain bloat …).

Don’t be afraid to make big changes fast to keep everything fresh and healthy. Celebrate small wins.

In general, I think we should look more to the people in the world who have never given much thought to Zcash or crypto. People who were 5 when Zcash was launched are going to be 13 soon.

One great thing about hobby mining is that it can be a magical family project and forces participants to learn some blockchain fundamentals, some economics, it can be really fun and a great learning experience.

Crucially, almost 100% of ZEC is KYC gated by centralized authorities in the current allocation. I think compliant, centralized platforms have important places in the ecosystem and I don’t have any beef with them. However, I think mining with commodity hardware can be an extremely awesome vector for reach and adoption that can bring magic to a crypto ecosystem that to me appears incredibly stale (metamask, ledger connect, dapps, nfts … ) compared to GPU mining with the family in the olden days.

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