Update: Antpool has indicated that the entire pool will be switched to Bitcoin Unlimited.

Antpool, Bitcoin’s largest mining pool, has begun mining blocks supporting Bitcoin Unlimited, cementing deadlock in the scaling debate as transaction issues worsen.

Last month, Bitcoin Unlimited briefly passed 25 percent of total blocks mined, indicating that a hard fork to increase the block size might be on the horizon. Though that rally did not last, now Unlimited is comfortably in the lead again thanks to Antpool beginning to mine Unlimited blocks, indicating that Bitcoin’s struggle over scaling solutions may be far from over. Meanwhile, transactions become slower and more expensive.

Antpool, Bitcoin’s largest mining pool, switching to Unlimited

While the tug-of-war continues between Segregated Witness, Bitcoin Core’s preferred upgrade to the network and Bitcoin Unlimited, a scaling solution championed by famed investor Roger Ver allowing miners to decide and implement a block size increase, a new development may tip the scales. Blocks mined by China-based Antpool, Bitcoin’s largest mining pool, increasingly support Unlimited, indicating that the pool may turn over completely in favor of a block size increase.

At the same time, Ver’s own mining pool, Bitcoin.com, was recently opened to the public, allowing for a greater increase in Unlimited’s chances of succeeding:

As a result, at present Bitcoin Unlimited represents over 30 percent of both hashpower and blocks mined, landing comfortably ahead of SegWit adoption for the time being.

The scaling debate remains in gridlock

Despite gains by Bitcoin Unlimited, however, the contest remains too close to accurately call, and both implementations, or neither, could succeed. Roger Ver points out that Unlimited is closer to implementation and present:

Charlie Lee, Litecoin’s founder and Coinbase’s Director of Engineering, insists that it’s SegWit that should be adopted instead:

Many debates have occured since hard forks to increase the block size were attempted almost two years ago has centered around not whether bigger blocks would allow Bitcoin to temporarily scale but whether or not increasing the block size would cause detrimental effects. Cornell University professor Emin Gün Sirer‏ opines that an increase in block size would not have such negative effects:

Bitcoin’s fees and transaction times are becoming worse

The gridlocked debate over scaling solutions has led to Bitcoin’s transaction times and fees, once the envy of the world’s payment systems, to become significantly less attractive. This year alone, Bitcoin’s mempool size of backlogged transactions has grown over tenfold. The average confirmation time for a Bitcoin transaction reached an all-time high of over two hours in February, since down to around 1.5 hours. Median fees have more than tripled this year.

As a result, Bitcoin-using businesses are feeling the effects. Popular point-of-sale system and Bitcoin debit card provider BitPay reports that the amount they spend on fees has been exponentially rising, having almost doubled since Christmas. Co-founder and CEO Stephen Pair, however, still believes that Bitcoin “is working perfectly.”

Usability issues may drive users to altcoins

All while Bitcoin has had its own scaling issues, the top altcoins have had quite the showing in the markets. Ethereum, Dash and Monero have all shot up over the past several weeks, bringing total altcoin market cap to an all-time high and taking Bitcoin’s percentage of cryptocurrency’s total value to a five-month low.

According to Robert Genito, project lead for peer-to-peer cryptocurrency trading platform Wall of Coins, companies and users can easily switch to a tool that better suits their needs:

“Genitrust only took about 60 man hours to switch our company over to being able to have our storage financial back-end be entirely Dash. Customers move quickly. Bitcoin needs to act just as quickly.”