Processing capacities of new high-speed roller ginning technology approaches that of saw ginning. Spinning mills are interested in mill performance data comparing new upland cultivars processed by both saw and roller ginning. Four diverse upland cultivars were processed by saw ginning and high-speed roller ginning and analyzed by ginning method. Ring-spun carded and combed yarns were produced, and their properties determined. Results overall (combining cultivars) showed that the roller gin, when compared to the saw gin, produced fiber that was more than 1 staple length longer, had two percentage points higher length uniformity, had 2.5 percentage points less short fiber, and contained 25% fewer neps. Yarn (carded and combed) produced from fiber from the roller gin, when compared to fiber from the saw gin, was about 0.2 percentage points more uniform, had 19% fewer thin places, 7.6% fewer thick places, and was 2.4% stronger. The roller gin lots had 30.8% fewer ends down than the saw gin lots when producing fine count combed yarn. Carded and combed yarns produced from the roller gin lots were consistently stronger for a given twist multiple than the saw gin lots, as demonstrated by twist strength curves. Spinning limit trials were conducted that demonstrated carded and combed yarn produced via high-speed roller ginning could be spun faster and into finer counts. The potential economic benefits of processing high-speed roller-ginned upland cotton in a textile mill were explored using data produced in the trials.