AIS 2012: Longer Ultrabook Battery Life
Ultrabooks haven’t been the smashing commercial success that Intel and it’s partners might have hoped for, but they’re still popular, and represent a big chunk of growth in the PC industry. We stopped by Kent Smith’s (of LSI SandForce fame) session on Ultrabooks and flash technology here at AIS to see about the future of those portables from a storage perspective.
As Ultrabooks get faster, lighter, and thinner with each iteration, more demands get placed on the battery system. After all, the battery is a big chunk of the weight and size characteristcs of an Ultrabook, so to get better time away from the wall new technologies are needed. Where storage is concerned, that means SSDs that use less power at idle, less at load, and can turn completely off when needed.
That’s not to say most SSDs use a lot of power — they don’t. But with most of the low hanging fruit gone already, new form factors, interfaces, and standards are needed for longer run times and new features.
The NGFF (Next Gen Form Factor) was proposed by Intel to get smaller SATA and eventually PCIe based SSDs into ever smaller packages. The standard NGFF card measures a scant 42mm x 22mm, but some could range up to 110mm long. The more interesting part is about the interface, as without the constraints of SATA, native PCIe based NGFF drives could be both much faster and much smaller. Lower SSD power consumption itself can be a large factor in governing total system power usage, especially idle wattage, but to really get the most minutes of usage, turning off the entire storage system is the best option.
RTD3 mode is essentially just that. The SATA PHY and the drive itself are using no power at all. This can help enable longer connected standby modes similar to today’s smartphones. The tradeoff is a longer delay from full-off back to on, which could take as long as 1000 milliseconds. There is a tradeoff between power usage and the user experience, even if the difference is miniscule.
Instead of fully disabling the storage subsystem it RTD3 mode, something called Device Sleep (or DevSleep) might be the answer. DevSleep is an intermediate mode, one which allows for longer smartphone-like connected standby states. Think of your phone; when it’s just locked and in your pocket, it’s still getting push notifications, texts, and emails but it can last for over a week in some cases. DevSleep lets the storage subsystem get by on 5 thousandths of a watt while still allowing the drive to rouse from it’s slumber quickly.
If it seems like the power consumed by the SSD itself isn’t a big deal, it turns out that’s not the case. As Intel’s processors bring more parts of the system on package, Microsoft’s new OS is making PCs more miserly. That means the low hanging fruit is gone, taking the fight for longer battery life to the storage arena. Building drives and interfaces with thin and light mobile PCs in mind can make a big difference, and SandForce has revised their controller to use less power, making it more ideal for Ultrabooks.
Will it all work out? Probably, but getting there won’t happen over night, nor will it be easy. Intel can just tell firms to use less power, but its up to those companies to actually make it happen.