Apple Introduces ASIF Format: Near-Native SSD Speeds for Encrypted Disk Images

Apple will also introduce a good progress in the area of ​​virtual storage technology with the upcoming MacOS 26 TAHOE. Encrypted disk images are massively accelerated and almost reach the speed of a native SSD.

Asif as a new standard

The format format (Asif). This massively improves the handling of disk images, which ultimately also include virtual machines. Disk images have long been part of the everyday life of many MAC users-whether for encrypted data storage or to use in virtualization. However, previous formats often suffered from slow access times, especially when the encryption is activated.

Even on the fast internal SSDs of modern Macs, the transfer rates were often less than 100 MB/s. Asif now brings a huge leap out: First tests With the beta of the new operating system shown at the WWDC developer conference, reading and writing speeds show that almost reaches the native performance of the SSDs. A 100 GB-Asif image on a MacBook Pro with M3 Pro reached 5.8 GB/s when reading and 6.6 GB/s when writing. Even with encryption, the values ​​remained high with 4.8 and 4.6 GB/s. On a Mac Mini with M4 Pro, even writing speeds of over 8 GB/s were measured.

Currently, ASIF-Images in MacOS 26 can only be created with the hard disk program or the terminal via discussion. So far, support from the widespread HDIUTIL tool is missing. In addition, the format can only be used under MacOS 26. Apple has not yet clarified whether and when earlier MacOS versions can read ASIF images.

Third developers are still waiting

The new technology for virtualization is particularly relevant. Apple recommends the switch from old RAW-Disk images to ASIF-not only because of the performance, but also because of the better handling during data exchange. In contrast to so -called “Sparse Bundles”, ASIF only manages with just one file, which simplifies the administration and brings additional speed.

While the developer community is waiting for more detailed documentation for ASIF integration in its applications, the first tools such as DropDMG are already preparing for the integration of the format. It remains to be seen when third-party solutions and virtualization apps can also exploit the full potential of ASIF.