The orange '120/240' voltage switch is for power supplies that do not have active PFC (power factor correction). The switch toggles a voltage doubler circuit. Since they don't have PFC, the power factor can be 0.6-0.8, which means that if the active power is 100w, the reactive power can be as high as 167 VA. This requires thicker cables and stresses the utility company's primary-to-secondary transformer.

This is an outdated design that is over 10 years old. Some OEM's like HP/Dell don't care because these older PSUs can be cheaper for them to buy in bulk, and a Dell Optiplex uses < 200w anyway. Never buy a PSU with a voltage switch, especially for mining. The minimum requirement should be active PFC, 80+ Bronze and 18AWG or thicker wires for the PCIe cables. I always buy 80+ Gold, though.

Power supply with the switch: Raidmax XT. Do not buy!

Here's a list of power supplies I would consider: 80+ Gold or higher

I also like server power supplies like the HP DPS-750AB/RB or a few Dell ones that breakout boards can be found for.

Can you try following this tutorial?

I remember that I had to do something like this to install the Radeon Blockchain driver a long time ago.

If one buys a Radeon RX 6800 card this week when they are at a discount somewhere, the price will be $700/card including the system components. The profit after 9¢/kWh will be $1.80/day after accounting for a 2-3%/month diff growth and assuming a crab market for ETH. If PoS happens on November 1st, one makes $320 of profit after pool/software fees. There is no way the price of the equipment can drop below $380/card even after PoS, as that would be 40% below MSRP. The lowest video card prices ever went was 50% of MSRP, which was back in 2018. But these days, there is much more gaming demand than before, as well as long-term miners who will bet on GPU mining. So it's very likely one makes a net profit.

Of course, if ETH price goes to $5000 again and PoS gets delayed further, it's possible to pay off the equipment before PoS.

If you thought 2021 was a very profitable mining year...
You don't remember what the gold rush of 2017 was like. You could buy RX 480's for $320 and make $6/day of profit.
But nothing compares to the Great Dogecoin Gold Rush of 2013, where a $250 Radeon HD 7870 video card made $10 per day of profit.

IDK how you can get 4¢ in PA unless you have a special deal with a power plant. The best-case scenario in the PECO service area with PJM index pricing, primary service and curtailment seems to be 6¢. Most places are 7-8.5¢. I spent days researching this. The other utilities (WestPenn/PPL/PenElec) charge more than PECO.

At least that's better than Joisey, where the lowest possible price (with PSE&G) is 7¢ while most small warehouses are 8-9¢. It might even be a cent higher this year with all the crappy ESG riders that were added to the tariff. I had to pay a ridiculous 11¢ in 2018 with JCP&L but thank god that was for GPU mining; I decided to pay the higher rate because that warehouse already had 1200A of power installed instead of 400A. Screw FirstEnergy. Of course, I called the utilities to verify these numbers.

Delaware is as bad as NJ, but at least there is no sales tax on power or equipment.

In northern Texas for ONCOR you can subtract 2¢ from the PA numbers. With ERCOT index energy, curtailment (96% uptime) and 500+ kW of primary service, the rate for the last 12 months was 5.1-5.5¢. I coded up a script to pull historical ERCOT prices and consulted with an energy broker to verify these numbers. Ultimately it was a no-go decision for other reasons, but TX seems to be the best place to start a farm for me.

Yes, there is the Bitmain Antminer S19j, but it's expensive and you should probably mine BTC/BCH because they're the most profitable coins on that hardware. Then you can trade in those coins for XEC.

I will never open a mining operation in New York for the same reason even though it's convenient for me! Yes, their electricity is cheap and the weather is colder, but is it worth fighting a bunch of old buereaucrats downstate who are alumni of Goldman/JPMorganChase/Citi who trash PoW as well as decentralized currencies? Hell no! Texas it is 🤠

PoS is going to be released in Q4 or later. That is plenty of time to make profit with a mining rig even if it declines in value. Keep in mind that PoS seemed imminent back in 2017 as the Difficulty Bomb exploded and blocks were getting frozen. That was a worse situation than right now.

Intel's higher-end cards have been delayed according to AIB's. They will only ship in volume in Q3. Not that they will be good for mining due to the poor memory bandwidth. Same for the next-gen AMD and nVidia chips, which will also have poor VRAM performance for mining.

I think these companies finally figured out that limiting memory bus width is better for discouraging miners than LHR. The other problem is NV might have 'LHR 2.0' which is harder to unlock. Currently, mining software fools LHR protection by running a dummy process on the GPU cores at the same time as ETH. It's possible NV engineers might patch this trick.

I certainly believe that the earliest ETH 2.0 is launched is September. It'll probably take December. If ETH price goes up, I think it's less likely the devs will want to take the risk.

I'm buying cards today because even if the value goes down by 20-25% by September, I'm betting the mining profit from those cards will more than compensate for the depreciation assuming ETH price stays constant w/ 3% monthly diff growth.

I would just try buying one or two of those 4-way PCIe x1 to USB splitter cards. Your existing motherboards might be able to support up to 12 cards each with this method.

I happened to get very lucky with a feeBay search where somebody listed their RX 6800's for $600 + free shipping because they wanted to get rid of them quickly. I activated the 5% eBay Bucks promotion on that day, as well as a 3% credit card bonus. So the price before sales tax turned out to be $552, while MSRP is $579.

You can buy up to 20 RTX 3060's (MSI Ventus 2X) on Newegg now for $390 per card.

I like the HP DPS-750RB/AB 750w series. You can probably run 3-4 cards on each one. The total cost, with a breakout board, will be $50 per PSU. The efficiency is 80+ Gold or Platinum.

Power the motherboards with cheap 400-550w ATX power supplies.

Do not use Windows for a farm this size. Install MinerstatOS instead. It has saved me a lot of time.

I like gaming motherboards because they can support 8-12 video cards while having less crashes and have higher resale value.

Dual mining isn't possible here because the cards only have 8GB of VRAM. Personally, I would've bought RTX 3060 12GB cards because they can dual mine to almost match the profit of an RTX 3060 Ti, while being much cheaper. The regular 3060 costs 21% less while only yielding 10% less profit per card. It used to be 0-5% less profit a few weeks ago.

I think it's a relatively good time to get into mining because video cards are only 30% above MSRP (in fact I grabbed a bunch of RX 6800's for below MSRP yesterday), while PoS will take at least 6 months.

My RTX 3080 Ti has the same issue. It can get up to 106° when dual mining ETH+CFX even at 100% fan speed. I just decided to mine ERG instead, so the temp. is under 90°.

I will no longer buy high-end RTX 3000 cards. I would rather get the RTX 3060 12GB go with AyyMD. It's much easier to deal with them even if I need more cards or MOBOs.

I greatly prefer mining over staking because of the upfront tax deductions I can get with mining. I pay 0% of taxes as long as I roll profit into new equipment. This isn't possible with buying coins.

NGreedia is done for. The entire AMD lineup will be significantly more power-efficient this generation for gaming. The top-end Navi 31 die will match the RTX 4090 in gaming performance while using 20-30% less power and being cheaper to make than the huge Nvidia 800mm+ monolith die.

However, all 3 manufacturers will offer poor memory bandwidth. This means current-gen cards will still be the most economical for mining and will hold their value as long as PoS is delayed & we're in a crab or bull market.

The data shows that less people are buying RTX 3070's for example:




I see the same pattern for the other cards. But as you can see, the number sold increases within 1-2 days after prices drop. After sales volume is good enough and cards can be sold quickly enough to satisfy sellers, or ETH price rises, sellers start to jack up prices. Buyers then react by purchasing less. The cycle starts over again.

This is why I've been predicting that GPU prices will stay steady for the next 1-2 months.

I have liquidated a farm with dozens of rigs before. While it's hard, it's not impossible if you're just disconnecting the video cards and leaving the rig alone. There were enough bulk buyers to go around even in late 2018, just at the right price. The average buyer bought 5-10 cards at a time, which made it easier to negotiate.

I absolutely think it was worth the effort to sell a few rigs for $200/card in June 2018 instead of watching them fall to $90/card by next year. That was the only reason I was able to buy a cheap right the next year, collect a bunch of coins and cash out later.

I do not think the ETH devs will prioritize PoS as long as the Ether price is > $2000. They would probably want to launch it during a recession, then when Ether price rebounds, they can claim 'PoS saved the coin'. They probably don't want to take the risk of crashing the price. The devs are funded by investors. What the investors want boils down to the coin price going up, regardless of energy consumption. The investors don't care about PoW or PoS, they just want their return.

I hope you're right, because I just grabbed a few RX 6800's at the incredible price of $570 below MSRP!!. I hope it turns out better than my RTX 3060 or P100 rigs.

I don't understand why this is a good idea. If you think the market will crash at a certain time, why not sell the cards right before that, then bet on buying them back later at a much lower price? Even after the inconvenience & fees of selling as well as the missed profit, it could make sense. You would end up with more hashrate for the same price, if your goal is to stack coins at low diff.

When miners bring up the idea of "ROI'd video cards", it sounds like the classic sunk cost fallacy to me.

Let's consider the RTX 3060's that I bought last month for $550 each. As of today, I lost money on that investment because the same card now costs $440, and I only made $50 of mining profit in the meantime. I would be an idiot to tell myself I didn't lose $60 so far.

Back in 2019 I bought GTX 1060 cards for $140 each, then made $400 of profit on each card by April 2021. I "made ROI" many times over on the investment. However, I was worried that ETH price was going to peak, so I sold off the rig for $350 per card in May. I turned out to be wrong. But if I were correct and the value crashed back to $140/card, there's no way I could have made $210 of profit beforehand.

Of course, if one thinks it's impossible to time the market, then I agree that buying/selling cards is a bad idea. But I don't think the GPU market is an efficient market like the stock exchange.