Primary limiting factor is ability to manage the 'bandwidth' necessary for streaming data to the disk. But any constriction of that data flow can be potentially damaging to recording process. So while rotational speed of a drive is used as a rough indicator of its suitability for recording the important numbers are read/write times and relationship between them. All of the variables of the system CPU 'speed'; amount of RAM, how it addressed; Type of Drive, drives data path; OS, etc. will effect efficiency of recording as a system.
RAM usage will be least effected by bit-rate/sample-frequency, (right up the point where rates are influenced by available RAM, a point that depends not merely on hardware as a whole but also on software application) The Actual A/D is (typically) handled by specialized chips/firmware in the converter so essentially the CPU manages the data stream and misc. overhead. If recording app is direct to disc very low CPU % is typical even with high track count. Drive topology remains the most significant bottleneck, partially because of dependence on mechanical processes. After a systems minimum specifications necessary for A/D recording the recording medium, i.e. HDD, is probably the most significant bottleneck. Followed by OS & recording applications. Once minimum specs are met the HDD is typically the one user amenable variable