Grin (GRIN), a major privacy-focused cryptocurrency, is apparently no longer resistant to mining with Application-Specific Integrated Circuits — or ASICs — according to a former core developer.

Gary Yu, a former core Grin developer, used a Grin ASIC mining device to test out the miner’s performance, according to an Aug. 10 post on Grin’s official forum.

Yu purportedly managed to mine three blocks in less than 24 hours, with a block reward totaling at 180 GRIN, or $118 as of press time. ASIC-powered mining occurred at block heights 819660, 820461, and 820801, Yu added.

In the post, the former core developer revealed that the Grin ASIC miner weighs about 20 kg. Yu also noted that the miner’s efficiency may be further expanded by adjusting the cooling system. He wrote:

“BTW, I tested it at my home, the big noise of the fan is a little bit annoying for the family, I have to limit the maximum fan speed to 30% for this test. I suppose the miner performance will be much better if let its fan work at maximum 100%.”

Grin is a major private cryptocurrency built on a privacy protocol known as Mimblewimble. To date, Grin has apparently been ASIC-resistant and only available for mining through Graphics Processing Units (GPU). 

In 2019, Grin executed the first hard fork of its blockchain to block the possibility of mining the coin with ASICs. Prior to the fork, Grin’s algorithm supported mining with both GPUs and ASICs, but no one used ASIC mining to mine Grin, developer John Tromp said at the time.

GPUs are less powerful or efficient in terms of crypto mining than ASICs — devices specifically designed to mine crypto. While ASICs are faster and require less power than GPUs, they are more expensive and harder to obtain.

Grin is not the only coin that has been positioned as ASIC-resistant. Monero (XMR), another major privacy coin, was upgraded to an ASIC-resistant mining algorithm in late 2019.

Amid the news, Grin has surged more than 11% over the past 24 hours. As of press time, the privacy coin is trading at about $0.66 with a market cap of $6.2 million, according to data from Coin360.

GRIN 24-hour price chart. Source: Coin360