Two of the largest bitcoin mining equipment manufacturers are in a neck-and-neck race to roll out top-of-the-line machines ahead of bitcoin's (BTC) halving event in less than three months.

On Thursday, Beijing-based mining giant Bitmain launched its latest AntMiner S19 and S19 Pro models, boasting computing power as high as 110 terahashes per second (TH/s) and an energy cost of 29.5 watts per terahash (W/T).

Going by the firm's specifications, the two models would currently be the most profitable bitcoin mining devices if available, closely followed by the WhatsMiner M30S from Bitmain's Shenzhen-based rival, MicroBT, according to a miner profitability index from f2pool.

The launch comes on the back of a heated battle between Bitmain and MicroBT, which has gained a significant share of the mining equipment business after selling about 600,000 units of its M20 series in 2019, chipping away at Bitmain's long-time market dominance.

MicroBT, which launched its flagship M30 models in December, has started taking pre-orders for the latest and most powerful product line since last week, with deliveries of sample units starting as early as next month.

According to MicroBT's major distributor Pangolin Miner, the M30S – priced at $2,430 apiece – touts a computing power of 86 TH/s with an energy cost of 38 W/T and uses 8-nanometer chips supplied by Samsung. The firm said some devices will ship from March to May, but large pre-orders would have to wait until as late as June.

On the other hand, prices and the pre-order/delivery dates for Bitmain's S19 models have not yet been announced. Adding to the uncertainty is whether Bitmain can deliver production on a large scale, since the latest models adopt 7-nm chips that come in limited supplies from its vendor, Taiwan Semiconductor Manufacturing Company.

It also remains to be seen how the industry will react to the releases of top-notch but more expensive mining equipment, as bitcoin's price has retracted from its recent growth momentum above $10,000.

Currently, Bitmain's older model the AntMiner S9 is still one of the most widely used miners, generating a daily gross margin of about 30 percent at bitcoin's current price, based on f2pool's index.

Further, the coronavirus outbreak in China has affected the country's manufacturing and logistics businesses, causing delays for those that were looking to expand or upgrade existing mining facilities.

In fact, data from mining pool BTC.com shows bitcoin's mining difficulty – a measure of how hard it is to compete for mining rewards – has stagnated for a month and is currently around the same level seen on Jan. 28.

But with bitcoin's halving event approaching in May, a programmed-in change that will reduce the network's mining rewards from 12.5 BTC per block to 6.25, older models like the S9 will become unprofitable unless bitcoin's price increases significantly. As such, miners may have to either upgrade or get out of the industry.