CHIPMAKER Intel will dump micro-SATA (mSATA) in favour of PCI Express for mobile storage.

Intel's present ultrabook specifications prescribe the use of solid state disk (SSD) drives that use the mSATA interface, the little brother of the desktop SATA connector. However the firm said that from 2014 it will be specifying PCI Express based SSDs, as the performance of the SATA interface, and the corresponding mSATA interface, will not be able to cope.

As Intel launches its Shark Bay ultrabook chipset the firm will incorporate support for PCI Express SSDs and reference designs for what the firm calls Next Generation Form Factor (NGFF) SSD modules. Intel showed off physical specifications for four designs that it expects to be deployed in specific use cases such as storage SSDs and cache SSDs.

Intel principal engineer Amber Huffman said "the SATA interface simply doesn't scale" with the bandwidth requirements posed by SSDs. She added that SSDs could saturate SATA3 interfaces at the launch of the Shark Bay chipset while proclaiming that "mSATA on the ultrabook is dead".

Huffman, who coauthored the AHCI specification, said that in order for developers to transition over to PCI Express they can make a PCI Express SSD appear as a single port AHCI device. However Huffman said that unlike AHCI, which "was designed for hard drives", non-volatile memory (NVM) on PCI Express will become the standard of choice, as it is not only designed for the PCI Express bus but also optimised for NAND based storage with high parallelism and low latency.

While Intel's NGFF looks a lot like the SSDs that are found in Apple's latest Macbook range of laptops, Huffman said it is not the same and that as far as she knew, "Apple wasn't pushing for standards compliance" in this area.

Fusion IO has made a name for itself by flogging PCI Express SSDs in enterprise kit, however Intel now expects the bus to be used in ultrabooks when its Shark Bay chipset arrives. The firm's NGFF could also provide support for server vendors that want very high density SSDs without the need for full size PCI Express cards.