Earlier this month mining groups began to complain about poor Internet connections affecting their work. Veteran miners have said that while mining does not always require very fast Internet connections, they have to be stable.
Normally, miners use Wi-Fi connections, but frequent cable breakages and suspension of services for maintenance have caused many to switch to 4G instead.
In cryptomining circles, 'stale share' is a term to describe a share that was submitted to a mining pool after a block has already been resolved, making it invalid and miners will not be able to retrieve the cryptocurrency. The higher the number of stale shares, the more losses for miners.
Lam Thanh Tung, a cryptominer in Ho Chi Minh City, said the number of stale shares depends on several factors, the most important one being the stability of the Internet connection.
In November last year, when Internet cables frequently experienced breakages, Tung's rate of stale shares was 32 percent, a huge rate considering 5 percent for certain cryptocurrencies like Ethermine is enough to make most of the mining rewards irrelevant, he said.
Many other miners also had to switch to more stable connections last November.
Quang Hieu, a representative of a group that assists people with installing cryptomining rigs in Dong Nai that bordes HCMC, said more and more people are using 4G connections to mine cryptocurrency, but it is possible only with small-scale rigs.
"One just needs a Dcom costing VND500,000 ($22) and a 4G SIM card, and a package that offers 1 GB a day to be able to operate a rig with eight Nvidia RTX 2060 graphic cards," he said.
The mining actually does not require the use of too much data, he added.
Replacing Wi-Fi connections with 4G is simple, but using 4G to mine requires expensive additional equipment and devices, miners said.
Ngoc Van, the administrator of a cryptomining group, said the optimal solution and the one preferred by many Vietnamese miners is to use both Wi-Fi and 4G.
"Large workshops often hire programmers to write a code to check the Internet connection stability. If the Wi-Fi wobbles, it would automatically switch to 4G."