Looking for a particular Asic miner

Experts in the house, good day, please I need info about Asic miners (not home miners) that has good modifications when it comes to lowering its power consumption, I can't find a thread where s19 was reduced to 70TH and makes the power go way lower, even if it's older. Asic miners I don't mind.

Why am I looking for one? A friend reached out to me, he wants a less cheaper Asic miner with high hashrate, that doesn't consume 3000+ watts, I know I've seen a thread but I don't know how to find it again, I think philipma worked on one in the past, doing some modification to the PSU.

This issue can't be resolved by modifying the power supply.
Download the VNISH firmware for the S19 90-95 TH/s and select the 70-80 TH/s operating mode with a power consumption of 1800-2200 W. You can also remove one ASIC board. The downside of the VNISH firmware is the mining fee.
You pay part of the reward to the owner of the firmware. Another option is to buy an Epic ASIC controller.
https://bitcointalk.org/index.php?topic=5568422

If your friend wants an S19-ish box doing roughly 70TH without drinking 3kW, the trick is usually underclocking and undervolting with aftermarket firmware. That's where people get those "old miner, much lower power" setups from. On these units, efficiency tuning matters a lot more than brute forcing the power supply. PSU mods get talked about like wizardry, but most of the time the real win is at the control and tuning layer, not with a screwdriver and a prayer.

For that target, I'd be looking at S19 variants that are known to behave well when tuned down, then run VNISH or similar and aim for the efficient part of the curve instead of maximum TH. That's the sweet spot. Once you start chasing cheap stuff with high hashrate and low watts all at once, physics starts charging extra. You can absolutely make an older unit behave better, but you're not turning a brick into a hummingbird. Sometimes the best deal is actually a slightly better miner run gently, not the cheapest one run like it owes rent.

Quote from: PocketAurora on April 17, 2026, 04:38:42 AM

The easiest option is to buy an S19k Pro instead of modifying an older S19. The Bitmain Antminer S19k Pro 115T 2645W already does about 115 TH/s while staying under 3000W if your friend wants something cheaper, a used Antminer S19 110T can be undervolted with Braiins OS or VNish. Many people run them at around 70–80 TH/s using only 1800–2200W, the thread you remember was probably about lowering the voltage and frequency through custom firmware, not changing the PSU itself, that is usually safer and easier.

Used ASIC prices in Russia for today
"S19 90th - $90
S19 95th - $95
S19j Pro 104th - $160
S19k Pro 120th - $280"
The Bitmain Antminer S19k Pro is a good ASIC, but the problem is that it costs three times more than the S19 90th. Perhaps the price ratios in your mining market are different.
For Solo mining, a difference of 10 terahashes isn't that significant.

I don't think modifying the PSU would reduce the power consumption of the unit; you might be talking about underclocking the unit using custom or modded firmwares like Vnish or Braiins OS (as suggested above) or upgrading to an Epic controller; this is mostly what Philipma mentions everywhere to have full control over/underclocking the unit.

Or if you are looking for unit that consume lower than 3000watts try using this tool https://www.asicminervalue.com/
Then filter them with only bitmain units and sort them to easily find those units with low consumption.

Currently, the best units I could find are the S19k Pro and the S19j Pro (slightly higher consumption), but you can run them with low power mode.

Bitmain has already implemented several operating modes into its ASIC firmware, depending on power consumption. If Bitmain implements the ability to use one or two boards, their ASICs will be in high demand on the secondary market for solo mining. Older Bitmain ASICs allowed mining on a single board, but this option was later removed.