Looking for efficient ASIC miners

Hey everyone, I need some insights on ASIC miners, not the home ones. I'm searching for models that can lower power usage effectively. I've read about some S19 modifications that bring it down to 70TH with lower consumption, but can't seem to find that thread again. A friend wants a cheaper miner with a decent hash rate that doesn't suck up over 3000 watts.

You won't solve this just by tweaking the PSU. Try VNISH firmware for the S19 90-95 TH/s and set it to 70-80 TH/s. It'll drop the power to around 1800-2200 W. You could even remove one ASIC board for more efficiency. Just keep in mind the mining fee with VNISH, you share some rewards with the firmware owner.

For an S19-ish miner around 70TH without hitting 3kW, underclocking and undervolting is key. Custom firmware makes a big difference here. Efficiency tuning is what really counts, not just messing with the PSU. Look for S19 variants that work well when tuned down and run something like VNISH.

Current prices for used ASICs in Russia: S19 90TH is about $90, S19 95TH is $95, S19j Pro 104TH is $160, and S19k Pro 120TH is around $280. The S19k Pro is solid but pricey compared to the S19 90TH. Just saying, for solo mining, 10 TH difference isn't a big deal.

I doubt modifying the PSU will help with power consumption. Custom firmware like VNISH or Braiins OS is the way to go, or upgrade to an Epic controller. That's what Philipma always suggests for better control. If you're after units under 3000 watts, check out this site to filter Bitmain units by low consumption.

Bitmain already has different modes in their firmware for power consumption. If they reintroduce single or dual board options, those ASICs will be hot on the secondary market. Older models allowed single board mining but lost that option later.

Are you sure about underclocking or undervolting an S19? Some folks run them at 70TH to cut down power but it's not a guaranteed fix. You gotta consider firmware, PSU, cooling, and chip quality. Lower wattage usually means lower hashrate too. Efficiency is what matters, not just lower power.

Only those with cheap or free electricity buy the S19 ASIC. In Russia, they cost around $100-$120, often used after some cleaning. Some miners use them solo, but it’s rare. Most likely, you’ll find one with VNISH firmware since the factory version isn't great.

Just buy the S19 and check my sig below. Get an Epic controller, swap it out, and you can tweak it however you want. You can disable boards, go full speed, or mix it up. Two boards at full speed use about 2k watts, one board at full speed uses about 1k. It's a bit noisy if you don't underclock, but you've got options.

What’s the hashrate if you disable two boards on an S19? I'm curious about how much you get using 1000 watts. Is it worth swapping the controller?

The control board and fans use about 80-120 watts. So with a 1000 watt limit, you’d have around 900 watts left for the hash boards, yielding about 26-30 TH/s. This has been discussed before, check the related threads.