I've been mulling over upgrading my miner recently and wanted to get some thoughts from real people who actually have some idea of what they're doing.

I first joined the pool in March of 2015 playing around with CPU and GPU mining mostly for fun. I eventually got a pair of those 5 chip LTC+BTC dual miners (orb something, I'd have to dig them out to see what they were called. One of them actually found a LTC block which was super cool!) My current setup consists of 2 L3's running Blissz 1.0.2. I got the first one in April of 2021 and the second in March of 2022. Neither one has been running nonstop since then, but they've both gotten a pretty decent amount of use. (In retrospect I shouldn't have gotten the second one however) I considered getting an L7 when they came out after the crypto bubble burst around that time and used miner prices dropped, but between the amount of power they draw, the excessive noise, the requirement for 220V, and the much higher upfront cost, I didn't end up getting one.


At this point I'm once again considering upgrading, but now things are even more complicated with the L9 being in the picture. Ultimately it has many of the same issues, ie noise, high power draw, 220V requirement, and still more expensive than an L7. As far as I can tell, the L7 is still profitable with a rather healthy margin, but obviously over time that will probably drop, and sooner than the L9.

I've been thinking about how I would address some of the barriers and would love if someone(s) could give me some feedback on it.

The noise is one of the biggest concerns I have. I run my L3's in the garage in the winter and that keeps them very comfortably quiet. (at the moment one is running ~2100 rpm and the other is ~2000 rpm) (I only tried installing Blissz on them last winter and immediately wish I had done it a loooong time ago, I'm amazed at how much quieter and more efficient I've been able to get them with it!) Anyway, I'm guessing that both the L7 and L9 would probably be substantially louder if for no other reason than they have 4 120 mm fans and 3 smaller ones for the built in PSU. However I think any noise issue could be solved by using a water cooling setup. From what I've seen, the L7 has a bunch of small heatsinks on the back of each board held on with some kind of permanent thermal adhesive/epoxy much like the L3 has on each individual ASIC, but the chips themselves are cooled with a single BIG heatsink that uses thermal compound and spring-loaded screws to keep it in good thermal contact, much like a regular computer CPU. If this *is* actually how it is configured, it seems like it shouldn't be too hard to buy or even make an easy-to-install water cooling system. (I'm almost certain I have all the tools needed to make my own water blocks, but it may or may not be easier to just buy them)

The power requirements are the other big concern. The biggest issue is needing 220V power. Living in the USA, most of the outlets in my house are 120V. We do have 220V power in our garage for a heater we rarely use, but it would require at least a little bit of re-wiring as it is hard wired directly into the junction box. Additionally, it happens to be on the opposite side of the garage from where I keep the miners, and running an L7 or L9 where the junction box would be less than ideal. (The L3's are located on the far side because none of the walls directly directly border any walls with the interior of the house, so it makes them totally silent from inside the house. There's also a lot more extra space over there, which would be especially nice if I added a water cooling system) We also have a pair of 220V circuits in a workshop I could use, but that isn't at our house. (My dad owns a business and he also loves tools, etc so he had a mini "warehouse" space added to the building when it was built, and a decent portion of it is a little machine shop) This comes with it's own disadvantages, as if it was going to live there it would definitely need to be fairly quiet so it doesn't interfere with the actual office part of the building. (nobody wants a distant hum/whine while they're trying to work) I also would have to ask our tech guy to make sure I could remotely access it securely, and I don't want to bother him too much if I can avoid it. I also wouldn't want to risk it interfering with their system in any other way either. The third option might be the easiest but to me also feels more sketchy than the other options. I'm reasonably sure there are at least 2 separate 120V circuits in our garage, and in theory I should be able to buy or DIY a cable that plugs into both of them in such a way as to put the two hot lines in series, giving me 240V. Basically I have 2 male connectors leading into 1 female connector. Obviously I would double and triple check that every part of the system, ie the breakers, the wiring in the walls, and any cables/connectors used could handle the current and voltage, but again in theory this should work. (On a semi-related note: I'm assuming that those heavy cables that split into 2 standard AC computer PSU cables are safe to use, and I don't need 2 separate cables coming from 2 separate 220V outlets?)

Another thing that might be worth asking is where a good place to buy one of these things is these days? Every miner I've owned has been bought used on ebay and I've never gotten scammed or had negative experiences with that, but I don't know if there are places where you can get them a bit cheaper without sacrificing the assurance that comes with buying something on ebay.

Finally, there's just the unanswerable question of "Should I even pursue this at all?" I miss the old days of low power, low noise, low cost miners that can comfortably live in your house. I feel like long term I don't need to worry about the upfront investment either way, but it's still a lot of money and its still resource intensive, single purpose hardware. I have a feeling that crypto in general is probably going to go up in the next few years, and that would probably mean now is the time to buy a new machine if I'm going to do it. (let's not get into politics, but with certain people in certain positions who have certain attitudes towards certain coins/chains, I think it's reasonably safe to say a catastrophic price drop in the near future is unlikely, and I wouldn't be surprised to see an increase either)


Anyway, sorry for the huge post that probably has more details and tangents than is strictly necessary, but this seemed as good a place as any to try and get some feedback from people who know at least as much as me and probably a LOT more. (I'm more knowledgeable than a your average random person walking down the street, but certainly far from an expert) I'd appreciate any thoughts, comments, critiques, ideas, etc anybody has!