By default, OffShoot uses minimal resources and thus runs on most Macs and PCs without issues. Any Mac or PC you can buy today will do fine.
Severe limitations in CPU and RAM might slow down transfers at some point, but in general, such computers also have other bottlenecks that impact interconnectivity (old USB standards, slow network connections, etc).
In two cases, OffShoot requires more RAM and/or CPU than nominal: huge transfers, and huge MHLs.
When Checkpoint is enabled OffShoot looks for, and parses, all Media Hash Lists (MHLs) on a Source. This is called MHL Awareness, and allows OffShoot to verify against original checksums, speeding up the transfer as it saves you from an additional source read operation. This process takes place during the Preparing... state of the Transfer and will use all available CPU power to accelerate it. When the transfer starts, CPU usage will return to normal; transfers themselves are not CPU-intensive at all.
As MHLs contain XML structures, any MHLs present on a Source will have to be kept in RAM for the duration of the transfer. A 100MB MHL describes about 250K files, and takes up ~1GB RAM.
Very large transfers also require more then nominal RAM. A source that contains a very large number of files requires more resources as its index and metadata have to be kept in RAM for duplicate detection and MHL Awareness. Rule of thumb: 1 million files take up to ~3GB RAM.
Are you transferring not a lot of files, but still find the Preparing... phase to take minutes? Do a Smart Search in Finder to locate orphaned MHLs, and delete or move them so that OffShoot won't parse them.
Which OS versions does OffShoot (and Hedge) currently support?
The current release of OffShoot works on macOS 10.15 and newer, which includes macOS 14 (Sonoma).
The most recent version of Hedge that works on 10.14 is 22.3.2
The most recent version of Hedge that works on 10.13 is 21.2.3.
The most recent version of Hedge that works on 10.12 is 20.3.2.
Neither OffShoot nor Hedge works on macOS 10.11 or older.