SSDs to use SATA for some time
NVMHCI interface might not be in Windows 7 either.
By Eric Lai, Computerworld US | Published: 06:53, 12 November 2008
Intel's next-generation interface for solid-state drives (SSD) promises to make them faster and last longer, but laptops will continue to use the Serial ATA (SATA) interface in the near-term.
Non-Volatile Memory Host Controller Interface (NVMHCI) was developed especially for SSDs, which use NAND flash memory rather than the magnetic spinning platters of conventional hard disk drives. NVMHCI is available today.
NVMHCI's raw transfer rate, 2.4Gb/sec., is actually a little slower than SATA's 3 GB/s., but it is far more efficient because it is optimized for how SSDs read and write data differently, Knut Grimsrud, a director of storage architecture for Intel, said last week at Microsoft's Windows Hardware Engineering Conference (WinHEC).
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Grimsrud, who is also chairman of the Open NAND Flash Interface (ONFI) working group, whose technology is closely aligned with NVMHCI, said performance testing in Intel's lab have been "pretty good."
"[NVMHCI] doesn't carry with it the baggage of 20-30 years of ATA hard drives," Grimsrud said.
The first generation of SSDs, mainly introduced in inexpensive netbooks last year, disappointed many customers who had expected performance to exceed that of hard disks. However, the poor performance was due to SSDs relying on kludgy hard disk interface emulations to transfer data to the PC's operating system.
Microsoft hinted at WinHEC that it was unlikely to suppport NVMHCI in Windows 7, despite the potential performance gains.
That is a reasonable stance, being that there are few NVMHCI products out today, Grimsrud said.
He doesn't expect that to change soon, either, being that vendors are likely to stay on the conventional SATA interface for notebook SSDs "for quite a while" rather than switch to NVMHCI.
One reason: The new SATA 3.0 standard will double its maximum bandwidth, up to 6GB per second. Grimsrud said PC vendors will likely prefer to adopt it over NVMHCI due to their familiarity with "existing infrastructure."
Stefan Hellmold, vice-president for marketing and business development at Seagate Corp., which plans to release its first SSDs next year, said the time taken for the new standards to catch on is always underestimated.
"People have the wrong expectations for how long it takes stuff to happen," said Hellmold. "Do we need an interface change [for SSDs]? Yes, but this is a 5 to 10 year process. It's not going to happen in a year."
Grimsrud said he expects the first use of NVMHCI would be for flash memory embedded into the motherboards of netbooks and laptops. Such embedded storage would compliment the main storage.