USB speeds
USB names were rebranded. USB 3.0 is now USB 3.2 Gen 1 at 5 Gbps. USB 3.1 Gen 2 is now USB 3.2 Gen 2 at 10 Gbps. USB 3.2 Gen 2x2 runs at 20 Gbps. These figures describe interface bandwidth, not real transfer speed. Actual results depend on the drive and controller. Typical HDD performance on USB 3 is 110 to 160 MB/s. SATA SSDs reach 430 to 520 MB/s. NVMe SSDs on USB 3.2 Gen 2 can exceed 900 MB/s.
Overall, USB 3.0 is sufficient for HDDs external drives, while USB 3.2 is preferable for SSDs.
PC USB speeds vs Mac
Apple and PC vendors use different units. Many PCs quote MB/s or Mbit/s. Apple often lists Gbps, matching Thunderbolt and USB standards. 1 GB/s equals roughly 8 Gbps. Numbers vary by drive type and port generation, not by operating system. USB and Thunderbolt deliver identical speeds on Mac and PC when using the same hardware.
USB-C and Thunderbolt 3 or 4 plugs look physically the same and fit each other. Thunderbolt 1 and 2 used a different connector shape and were not USB-compatible.
Does PC USB work on Mac
USB 3 works on all Macs from 2012 forward. USB 3.2 and USB4 ports are supported on Apple Silicon models. No software is required for standard USB storage. Older Macs with USB 2 ports will operate at USB 2 speeds unless using a supported expansion card or dock.
| PC and Mac | Mac only | |||
|---|---|---|---|---|
| USB 2.0 | USB 3.x | USB4 | Thunderbolt 1, 2, 3, 4 | |
| Single HDD | 30 | 110 to 160 | 160 to 200 |
TB1: 160 to 200 TB2: 160 to 220 TB3: 160 to 260 TB4: 160 to 260 |
| Single SATA SSD | 30 | 430 to 520 | 520 to 700 |
TB1: 520 to 650 TB2: 520 to 700 TB3: 520 to 900 TB4: 520 to 900 |
| RRP Price per 1 TB of data | $185 | $200 | $240 | $325 |
When buying external USB drives
USB standards are not the same as the physical port. The USB-C shape began with USB 3.1 but can also carry older USB 2.0 signaling. When buying an external drive, make sure the connector matches your device (USB-A or USB-C) and that the standard is at least USB 3.0 for HDDs and USB 3.2 for SSDs.
Drive formatting
PC and Mac share the same USB storage standards. Drive formatting affects compatibility. Windows cannot read HFS+ or APFS without extra software. macOS can read NTFS but cannot write to it without tools. exFAT offers read and write support on both systems and handles large files, but improper ejection or weak hubs increase corruption risk.
macOS can also read and write FAT32 for older or cross-platform devices, although FAT32 is limited to 4 GB per file and is even more prone to corruption than exFAT.