The following describes file system performance on Wii U. The current investigation covers device and file system combination test results only. See the File System Types and Overview topic to discover how each device and file system combination works in which access method, and use it as reference for application development.
In the future, the plan is to show values for each media to start from and per API.
The results shown here were obtained by directly performing Read/Write processing that takes place internally while no background (BG) processing was taking place. It may not directly reflect the performance for when actual FS APIs are used. The overhead associated with an API may be reduced by allocating some buffer size; however, exercise caution with background processing. See documentation on BG stress mode and such for more information.
Test results obtained by accessing the system NAND memory via WFS are as shown below. The SDK version used for this testing was SDK 2.07.03 Patch 5, SDK 2.08.11, and SDK 2.10.02.
|SDK 2.07.03 Patch 5||SDK 2.08.11||SDK 2.10.02|
|Read||64KB||Approximately 10.9MB/s||Approximately 10.6MB/s||Approximately 11.1MB/s|
|512KB||Approximately 14.0MB/s||Approximately 14.0MB/s||Approximately 15.8MB/s|
|2MB||Approximately 14.8MB/s||Approximately 14.7MB/s||Approximately 15.9MB/s|
|Write||64KB||Approximately 1.2MB/s||Approximately 1.2MB/s||Approximately 1.2MB/s|
|512KB||Approximately 2.5MB/s||Approximately 2.5MB/s||Approximately 2.5MB/s|
|2MB||Approximately 2.5MB/s||Approximately 2.5MB/s||Approximately 2.5MB/s|
Test results obtained by accessing the disc via ATFS are as shown below. The SDK version used for this testing was SDK 2.07.01.
|Inner (of disc)||Middle||Outer|
|Read||64KB||Approximately 11.3MB/s||Approximately 16.0MB/s||Approximately 16.8MB/s|
|512KB||Approximately 11.3MB/s||Approximately 16.0MB/s||Approximately 20.9MB/s|
|2MB||Approximately 11.3MB/s||Approximately 16.0MB/s||Approximately 20.9MB/s|
Test results obtained by accessing the USB storage via WFS are as shown below. The SDK version used for this testing was SDK 2.08.00.
The SDK version used for this testing was SDK 2.10.02.
The SDK version used for this testing was SDK 2.08.11.
The SDK version used for this testing was SDK 2.08.00.
|Read||64KB||Approximately 7.61 ~ 9.05MB/s|
|512KB||Approximately 10.5 ~ 21.4MB/s|
|2MB||Approximately 10.6 ~ 22.1MB/s|
The USB storage used for this testing are as follows:
In Debug systems (CAT-DEV), it is possible to use the host PC to emulate other filesystems via PCFS.
The SDK version used for this testing was SDK 2.09.09 with Hostbridge 22.214.171.124.
|Read||512 bytes||Approximately 170KB/s|
|16KB||Approximately 5 MB/s|
|Write||512 bytes||Approximately 170KB/s|
PCFS went through recent changes that drastically improved performance.
It is preferable to use the latest available Host Bridge and SDK combination.
The charts below help illustrate the advantages of using the latest software.
Detailed data can be seen here
Test results obtained by accessing the disc via FAT are as shown below. The SDK version used for this testing was SDK 2.10.02.
Due to processing overhead, to some degree, the more you increase the buffer size, the better performance becomes.
However, if the buffer size unit is not 64KB, no sufficient performance may be achieved. It is recommended to use 64KB as buffer size unit.
Also, as mentioned in the caution above, background processing may affect the performance significantly; due to flushing that cannot be interrupted, processing may become delayed by hundreds of msec. For this reason, to stream a movie, a buffer for more than 1 - 2 second-frame should be allocated.
2015/02/10 Added link to more info on 'BG Stress Mode'
2014/09/11 Added information about jumbo frames.
2013/08/26 Added caution to state that the results shown here do not guarantee anything about performance. Updated performance information for system NAND memory, Wii USB memory, and SD Card. Removed write speed (that were TBD) from "other USB storage devices".
2013/05/08 Automated cleanup pass.
2012/12/18 Updated NAND and USB performance.
2012/11/20 Replaced "FAT32" to "FAT".
2012/10/17 Added USB performance.
2012/08/22 Initial version.