Topic: [Guide] Solo mine testnet bitcoins with bfgminer, Bitcoin Core, and a CPU/GPU (Read 1385 times)

Of course it will repeat on testnet4. But, as I said in another topic, the solution is to improve the code in your Bitcoin Core node, not in your mining equipment. Think about it, and use proper rules, to always work on blocks with minimal difficulty.

Of course it doesn't make any sense. However, as long as testnet rules are quite close to mainnet ones (in both: testnet3 and testnet4), those coins are doomed to get some value over time. And then, it is all about having enough support for more frequent resets.

It is already possible. There are quite frequent block reorgs, but besides that, it works even on testnet3.

There already is a max difficulty, but nobody reached it yet, even on mainnet. Each hash is just a 256-bit number, and if you create SHA-256 hash of almost all zeroes, then you will reach the max.

This one we have as well, currently set into year 2106 or year 2038, depending on Bitcoin Core version (some of them are buggy).

Well, if you reset things more often than every four years, then you have no chance to test any halvings, and then you can permanently set basic block reward into 50 tBTC.

We already have something like that in signet: anyone can just pick a new signet challenge, and it will start a brand new network. And if you pick OP_TRUE, then it is more or less the same as testnet4, but without 20 minute block rule.

Makes you wonder if a very minor change (yeah I know there is no such thing as a minor change) but setting a max difficulty in testnet and known EOL would help.
So yeah mine all you want with whatever ASIC you have as of Jan 1 2025 testnet 4 is going to become testnet 5 and Jan 1 2026 testnet 5 goes away and becomes testnet
And so on.

It's not like the old testnets will stop working just new ones will start.

Not going to happen and there are probably 100s of reasons why it's not a good idea but it's at least a thought.

-Dave

It seems that one or more entities already throw some spare ASICs to mine in Testnet4, hell, for whatever reasons. It takes just one to force others to follow that path and leave everybody else without ASICs behind. Anyway, in a trustless PoW scenario miners can do what they're are able to with their gear, you can't control that. Why wouldn't history of Testnet3 repeat in Testnet4?

Does it make sense to drive difficulty up to levels where only few dare to waste money for energy for a worthless-by-design-and-intention coin like tBTC? I don't think so.

It would be more fun for participants to be able to mine Testnet4 with CPU cycles in a truely decentralized fashion. But that's not gonna work with human mindsets unfortunately. Only if we had an ASIC-resistant hashing algorithm for Testnet4, but then Testnet4 would diverge from Mainnet too much.

Hi, mining on testnet4 worked for me with bfgminer and a bitcoin core testnet4 node, compiled as mentioned in this thread:


and with this .config:


The difficulty is already too high tough that it would make sense to mine on a CPU/GPU.

hi guys,

have u guys tried to mine bitcoin on testnet4?

Since openssl is a dependency, I suppose it already uses that. Furthermore, this isn't nullama's software. I'm pretty sure it was first released (and maintained - last commit in '21) by Luke Dashjr ^[1-2].

[1] https://github.com/luke-jr/bfgminer/
[2] https://en.bitcoin.it/wiki/BFGMiner

I ran it like suggested by nullama just for benchmarking:

16/02/2023

RX6600 (bfgminer):

RX6700XT (cgminer):

I would enjoy seeing what a 4090 can achieve

When you use the benchmark option the difficulty by default is 1. It doesn't connect to any network.

Did you create your own Fork that stays on difficulty 1?

if there's demand now what's really needed is instructions for cpu with AES support. for sure regular sha256() ,openssl, with hardware aes turned on there , is faster than yours now.

That's good to know. How about compiling a list of modern desktop hardware just for fun? Then it could be added to ^[1] the Bitcoin Wiki, which as of now only has very old hardware listed.
I think it would be good to post at least a console output from bfgminer as proof.

[1] https://en.bitcoin.it/wiki/Mining_Hardware_Comparison

---

Very odd. I quickly logged into a VM of mine with 7 cores (underlying CPU is pretty new Intel model boosting to almost 5GHz); the benchmark only results in ~20MH/s (probably due to virtualization), yet still I got an accepted hash after 7 minutes, another 3 minutes later and another one minute later.


I will test on bare-metal hardware with Bitcoin Core on the weekend, as mentioned before. Maybe there is hope for Loyce's 7MH/s second machine (although it makes no sense on paper - even getting accepted hashes that fast with 20MH/s...).

SSE is not supported in an ARM device like the M1.


That's per core, the M1 has 8 cores.

In an Intel CPU:


That's per core, the CPU had 20 cores. Also, I've seen the sse4_64 algo being the fastest at other times in the same CPU.

Note that this is bfgminer, with CPU. This is not supposed to have the latest CPU optimizations enabled as it's not used for that in years, maybe a decade or more.

did you use sse at least? say sse3.1 have some stuff for that. avx too

For comparison purposes a single RX 6600 achieves 1500Mh/s in cgminer/bfgminer

CPU mining absolutely works for testnet with relatively new devices.

Just did a quick benchmark with bfgminer on a mac mini M1(2020 device) with CPU only(you can also use OpenCL to use the GPU), and in less than 5 minutes I got 2 shares over Diff 1:


You can see that it is absolutely possible to find a block when Diff is 1 with a CPU. It's just that it's way less probable than with an ASIC.

If you want to test a device without having to setup a local Bitcoin Core, you can do this:


Also, notice the M1 hashrate hovering around 20Mh/s or so. It should be higher than that because I did the benchmark while using the device at 100% for other intensive tasks that I didn't want to stop.

I think many folks here share this sentiment.

Sure, but if you have it already and need a bunch of testnet BTC, it should work nicely. I will try on the weekend with some modern desktop general-purpose hardware that I can access. I was surprised to see a >100MH/s hashrate on CPUs, since yours only managed single digits. Therefore, I was about to call this guide half-failed (the CPU part), but those benchmarks give me hope.

Don't remind me I should have done that when I first read about Bitcoin, which was years before I joined Bitcointalk.

It's old indeed, but works very well for it's task: pushing bytes to the outside world.
This Xeon CPU is already faster in finding Bitcoin vanity addresses than my laptop GPU.

Buying a CPU just for hashing is a waste of money (and electricity). That's 95W that could be used for better things.

The 10 minute figure is correct:


Indeed, yes. The whole network hash rate in the beginning of 2009 was relatively stable around 4-5MH/s ^[1]. A new CPU from Q1 2009 like the Intel Pentium E5400 ^[2] was already able to output about 2.2MH/s ^[3], so there were literally just 2 CPUs on the whole network for almost a year back then. It somewhat surprises me that more people did not spin up a rig just for fun, but on the other hand the coin was worthless and energy & hardware did cost something.

[1] https://www.coinwarz.com/mining/bitcoin/hashrate-chart/2009
[2] https://ark.intel.com/content/www/us/en/ark/products/40478/intel-pentium-processor-e5400-2m-cache-2-70-ghz-800-mhz-fsb.html
[3] https://bitcointalksearch.org/topic/hash-rate-cpu-comparison-table-1628

---

@LoyceV, after browsing a bit online, it seems like there are modern CPUs now that can compete with something like ETFBitcoin's 100MH/s GPU.
It's just that your CPU is old.. old old..


From 2011 to 2023, well, things changed. An i9-9900K from Q4 2018 even manages over 100MH/s, it seems like. ^[4]
I will verify with some relatively modern Desktop hardware, later myself directly with bfgminer and report back.

Sadly, @nullama's assumption (I guess he assumed that, like myself?) that difficulty=1 means an immediate hit on any hardware, was wrong. However, with a modern computer you should definitely get something, if you have a few hundred MH/s.

[4] https://forum.level1techs.com/t/whats-the-fastest-processor-for-single-threaded-single-process-of-running-sha256sum/157464?page=3

In a way it makes sense: mining on one computer produces one block per 10 minutes. That sounds exactly like the beginning of Bitcoin.

To conclude this: I give up After wasting another week of CPU time without finding a block, I wiped the testnet installation. Using a testnet faucet is much faster if you need some.