But the fastest growth happened after NEP was reversed and full state control of the economy was restored.
Also China in the early 50s was basically operating under similar circumstances to the NEP for about as long, before they'd built out the bureaucracy enough to start collectivizing and building a (very, very loose) central planning and logistics system.
From quick googling, Russia’s GDP per capita was $1400 compared to China’s $600.
There are more specific figures focused on actual material productive capacity like tons of steel that could be produced per year, but you're correct here that the industrial underdevelopment is the heart of the issue they faced. 1917 Russia is often described as an undeveloped backwater, but 1950 China had less total industrial capital with a bigger populace, and that became the heart of the problem that they tried and tried to untangle with various success and failures until they started collaborating with the US and got a constant stream of modern industrial capital in exchange for turning their educated populace and logistics systems to commodity production for export.
Through the Mao-era specifically, their biggest ongoing issue was trying to balance industrial buildup in the cities with food production and expropriation in rural areas as well as the mechanization of agriculture and logistics. Where the Soviets had been able to rapidly industrialize through agricultural collectivization and the mass migration of workers from the countryside to new factories, China lacked enough mechanized capital to facilitate increases in agricultural productivity per amount of labor and so had a constant fight to stop the migration of workers from the countryside to cities because with less agricultural labor there wouldn't be enough food grown to support those same cities. So they were stuck in a constant state of both capital and labor shortages and after the catastrophe of the Great Leap Forward their leadership chose safe stagnation and even slower growth than another push to rapidly industrialize (until Deng and China's collaboration with the US for industrial capital).
Also China in the early 50s was basically operating under similar circumstances to the NEP for about as long, before they'd built out the bureaucracy enough to start collectivizing and building a (very, very loose) central planning and logistics system.
There are more specific figures focused on actual material productive capacity like tons of steel that could be produced per year, but you're correct here that the industrial underdevelopment is the heart of the issue they faced. 1917 Russia is often described as an undeveloped backwater, but 1950 China had less total industrial capital with a bigger populace, and that became the heart of the problem that they tried and tried to untangle with various success and failures until they started collaborating with the US and got a constant stream of modern industrial capital in exchange for turning their educated populace and logistics systems to commodity production for export.
Through the Mao-era specifically, their biggest ongoing issue was trying to balance industrial buildup in the cities with food production and expropriation in rural areas as well as the mechanization of agriculture and logistics. Where the Soviets had been able to rapidly industrialize through agricultural collectivization and the mass migration of workers from the countryside to new factories, China lacked enough mechanized capital to facilitate increases in agricultural productivity per amount of labor and so had a constant fight to stop the migration of workers from the countryside to cities because with less agricultural labor there wouldn't be enough food grown to support those same cities. So they were stuck in a constant state of both capital and labor shortages and after the catastrophe of the Great Leap Forward their leadership chose safe stagnation and even slower growth than another push to rapidly industrialize (until Deng and China's collaboration with the US for industrial capital).