It looks like you're comparing USB E12 and USB E34 — but these are not standard USB specifications (like USB 2.0, 3.0, USB-C).
When building a PC, you will often find multiple 9-pin headers on the bottom edge of the motherboard labeled with these alphanumeric codes. usb e12 vs usb e34
If you are looking at NVMe SSDs:
USB_E34 (Ports 3 & 4): Refers to the second pair of USB ports. Depending on your motherboard's specific chipset, this header may support the same speed as E12 or potentially a faster standard like USB 3.2 Gen 2, which reaches up to 10 Gbps. Comparison Table USB_E12 (Standard) USB_E34 (Standard) Typical Speed Up to 5 Gbps (USB 3.2 Gen 1) Up to 10 Gbps (USB 3.2 Gen 2) Port Mapping Front Panel Ports 1 & 2 Front Panel Ports 3 & 4 Common Use General peripherals (Mouse, Keyboard) High-speed data (External SSDs) Compatibility Backward compatible with USB 2.0 Backward compatible with USB 2.0 Practical Advice for PC Building It looks like you're comparing USB E12 and
Connector type
Because the E12 shell is small, it struggles to accommodate the 4 extra wires required for USB 3.0 SuperSpeed (which needs 9 pins total plus shielding). When building a PC, you will often find