emUSB-Host Performance
The following values have been tested using the CDC-ACM protocol.
System with Synopsys (USB High-Speed) Controller *
Measurements
Description | Speed |
|---|---|
| Write speed | 38.4 MiB/s |
| Read speed | 39.0 MiB/s |
System Configuration
| Detail | Description |
|---|---|
| CPU | Cortex-M7 running with 180 MHz |
| Test Device | emPower board running emUSB-Device |
| Test Protocol | CDC-ACM protocol |
| Transfer Block Size | 200 MiB |
System with EHCI (USB High-Speed) Controller *
Measurements
| Description | Speed |
|---|---|
| Write speed | 30.9 MiB/s |
| Read speed | 36.0 MiB/s |
System Configuration
| Detail | Description |
|---|---|
| CPU | Cortex-M4 running with 180 MHz |
| Test Device | emPower board running emUSB-Device |
| Test Protocol | CDC-ACM protocol |
| Transfer Block Size | 200 MiB |
System with OHCI (USB Full-Speed) Controller *
Measurements
| Description | Speed |
|---|---|
| Write speed | 800 KByte/sec |
| Read speed | 800 KByte/sec |
System Configuration
| Detail | Description |
|---|---|
| CPU | Cortex-A5 running with 498 MHz |
| Test Device | emPower board running emUSB-Device |
| Test Protocol | CDC-ACM protocol |
| Transfer Block Size | 5 MiB |
* The performance of a USB communication depends on a multitude of factors: hubs, low transfer sizes can reduce the performance. Most importantly the device needs to be able to achieve the same speed as the host for good performance values.