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Adaptec Intelligent Power Management FAQs

Contents:

  

 

What is Adaptec Intelligent Power Management?   top of page

Adaptec Intelligent Power Management allows users to choose from 3 levels of disk drive power modes: 1) Normal operation - full power, full RPM (revolutions per minute), 2) Standby - low-power mode spins disks at lower RPM, and 3) Power-off – disks not spinning - to reduce power and cooling energy consumption by as much as 70% without compromising application performance. Included standard with Adaptec Series 5 and Series 2 Unified Serial TM raid adapters, it offers the industry's first automated and configurable disk drive power management functionality on a RAID adapter.

 

Why should I care about power management?   top of page

The expense of powering and cooling disk drives is a primary cost in operating a server. In most servers, full power is maintained to every drive at all times, even when the drive is inactive. This constant full power state also increases the costs of cooling the system.

At current energy rates, the cost of operating a server over a typical four-year lifespan is about the same as its initial purchase price. IDC estimates that more than US$10B will be spent on energy costs worldwide in 2008 to power and cool servers. As much as 40% of that figure will be spent on rotating and cooling the disk drives inside the servers.

As a result, many companies have started to look at different metrics when purchasing IT equipment. Instead of concentrating solely on brute computational power, companies are beginning to factor an item's ratio of computational power per watt of electrical power into their purchase decisions. This new focus on power optimization is taking place in both larger data centers where the supply of electricity is limited as well as in smaller organizations looking for cost savings.

 

What disk-based storage applications will benefit from Intelligent Power Management?   top of page

Potential savings depend on usage patterns of the application.

For example, a typical SATA II or SAS disk drive can consume between 8W and 15W of electrical power when running at full speed. Studies show that the power required to cool these components is roughly the same, for a total power draw of 16W-30W per disk drive. When spun down, these drives typically use a total of 3W-5W – a relative savings of 75%-85% depending on the drive.

Consider a typical fileserver in a small or medium business that operates on a 5-day work week. This device is probably used for much of the working day, and is mostly idle during nights and weekends. As a result, the system is in use for about 40-50 hours of the 168-hour week. If you could spin down the drives when the system isn't active, you could save power during the 130 hours that the system isn't in use – 77% of the time.

Other systems may be in use even less frequently. A server used for a nightly disk-to-disk backup might only spin its disks for 2-3 hours each night. The same applies to an archiving system, a print server or fax server. Even general-purpose servers running applications can have usage patterns with significant idle time. An accounting system, for example, might only be active during business hours, and a high-end transactional application, such as ERP, can have significant periods of inactivity.

This issue isn't only restricted to general-purpose computing systems. Specialty equipment in other industries such as medical, industrial manufacturing, or video processing is likely to have periods when its I/O subsystems are basically idle.

 

What are the benefits of Intelligent Power Management?   top of page

Intelligent Power Management reduces energy use by up to 70% without compromising application performance. In addition, it offers:

  • Automated, customer-configurable scheduling
  • Support for both SATA and SAS disk drives
  • Support for applications with idle time such as disk-to-disk backup/VTL, email archives, and File/Print servers
  • Decreased cooling costs

 

 

Is Adaptec Storage Manager pre-configured to have Intelligent Power Management enabled or disabled?   top of page

Intelligent Power Management is disabled in Adaptec Storage Manager's default settings. It must be manually enabled in order to begin reducing disk drive power consumption.

 

Can customers who currently have Adaptec Series 5 and Series 2 raid adapters get Intelligent Power Management capabilities?   top of page

Contact your Adaptec Sales Representative or Technical Support for more information.

 

Is Intelligent Power Management compatible with “green” power-saving disk drives?   top of page

Yes. Adaptec has verified the compatibility of our Series 5 and Series 2 controllers with more than 300 disk drives, motherboards, and chassis. Intelligent Power Management is 100% compatible with the latest low-power “green” disk drives, and helps them deliver even greater power savings than they offer on their own.

 

How will decreasing and increasing the rate at which disk drives spin affect the drive? Will Intelligent Power Management result in more drive failures?   top of page

SATA disk drives are manufactured for duty cycles that include powering on and off. SAS disk drives are built to an even higher tolerance. Spinning down drives when the system is not in use will not harm the disk drive or cause the drives to fail any more or less often than if the drive is left spinning all the time.

 

Won't the power savings from spinning drives down be lost when you spin the drives back up because it takes more energy to spin the drives back up?   top of page

Intelligent Power Management is designed to reduce a disk drive's overall power consumption, and therefore avoids scenarios in which drives are continuously spun up and down. To achieve this goal, Intelligent Power Management has several built-in features, including:

  • User-definable timeout periods that determine which drives are put in Standby or Power-off state
  • A user-definable period that disables power management (e.g. during working hours)
  • Intelligent adapter cache management, which avoids spinning up drives in situations where only small amount of data is written (e.g. time stamps)

These features ensure that disks are spun up on time intervals that are large enough to save energy and avoid unnecessary delays.

 

For 12, 16, 24+ drive configurations, will spinning drives up and down put a higher load on the system power supplies and cause them to fail?   top of page

Adaptec Series 5 and Series 2 raid adapters support “staggered drive spin up,” which is a technique that brings up only a few drives at a time. This reduces the power needed to spin the drives back up and will prevent power-related issues with server and storage systems.


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