Microsoft Mentions Windows 7 SP1 and Vista SP3

Last Updated on Monday, 12 October 2009 10:05 Written by Mire_B Monday, 12 October 2009 10:05

This fell in my lap over the weekend, but I didn’t have time to cover it last week: An update is available that allows for a potential power saving in an AMD multicore processor that is running an x64-based version of Windows Vista SP2, of Windows Server 2008 SP2, of Windows 7, or of Windows Server 2008 R2.

The update in itself is worth a download and an install, to make post-Vista 64-bit platforms play nice with Enhanced C1 state (C1E) for lower power consumption for an AMD multicore processor. But what is interesting is that under Hotfix Support for Windows 7/Windows Server 2008 R2 it says SP1 (Service Pack 1) and SP3 for Vista.

Could the first service pack for Windows 7 already have started shaping up, when the product will only be offered to customers on October 22nd? Considering the July 22nd release to manufacturing date, I would say yes. Microsoft is not releasing hotfixes to all Windows users, but it is traditionally including the bit in the next service pack. The x64 Windows 7 C1E hotfix can be deployed in the RTM build of the operating system, but it won’t see a wide release until it will be included into Windows 7 SP1.

And of course Vista SP3 is already in the making. SP2 was released to manufacturing on April 28th. I would dare say that at this point in time, the RTM of Vista SP3 is less than a year away, and that it will a minor service pack release, just like SP1 and SP2.

Update Information

The local Advanced Programmable Interrupt Controller (APIC) timer is programmed to count even when it is not being used. Therefore, the local APIC timer runs in the C1 sleep state continuously at a constant rate regardless of performance state (P-state) transitions. This behavior causes the computer to consume unnecessary power. However, AMD processors support an inactive state for when the CPU APIC timer is not being used. Therefore, an AMD processor can enter the low-power C1E state. This low-power state saves up to an additional 10 percent in power.

If your processor supports the C1E state, you can apply this update to allow for the potential power savings of the C1E sleep state.