The report followed four day operations by the 13-strong evaluation commission led by Chiharu Igaya, IOC vice-president, to each of the candidate cities.
A full session of the IOC is due to select the host city for the 2014 Winter Olympics on July 4 at a meeting in Guatemala, but a strong technical report does not guarantee that a city will win the vote.
Both Pyeongchnag and Salzburg offered "excellent" concepts, but the guarantees provided to ensure that what is planned can turn into reality were "generally of a high quality" for the South Koreans, the report said.
However, Sochi's concept was merely regarded as "very good" even if the $1.52bn budget was "achievable".
The report warned that the need to build most, if not all of the 11 planned Russian venues "would require robust construction methods" and tight monitoring "in order to ensure timely delivery for the Games."
The evaluation commission criticised Salzburg's bid for a shortage of detail.
"Whilst the Austrian government has guaranteed to cover all security costs, Salzburg appears to have underestimated the resources required for security operations," they added.
The overall predicted budget of $965m was "relatively low" compared to previous Winter Olympics, while their transport plans also had shortcomings.
The report said spectator capacity at the Austrian mountain venues for snow sports might have to be reduced to meet transport constraints.
Demands fully met
By contrast, Pyeongchang's $1.26bn budget was considered "achievable".
"With a compact Olympic Winter Games concept, the implementation of a dedicated Olympic lane network and the completion of a high speed rail line, the Commission believes that transport demands would be fully met," the report added.
Apart from Salzburg's technical shortcomings against its South Korean rival, its bid also has the added political drawback of the unresolved doping scandal hanging over the Austrian team following last year's Winter Olympics in Turin, Italy.
Olympic chiefs imposed a record $1m sanction on Austria last month and warned the Austrians that they must get to the bottom of the scandal.
The evaluation report added an unusual general warning about the impact of climate change by 2014 and the prospect of warmer winters, less reliable snowfall, and more extreme weather conditions.
It said the IOC would have to pay more attention to issues such as the altitude of snow sport venues, as well as the cost and environmental impact of measures such artificial snowmaking and growing transport needs.