Suspend to RAM (S3) support for chipsets that don't support S3
Original Publication Date: 2005-Mar-09
Included in the Prior Art Database: 2005-Mar-09
BladeCenter customers would like to install desktop operating systems on server platforms because it's cheaper. Microsoft, starting in 2005, will require desktop operating systems to support Suspend to RAM (S3) state. Several drawbacks exist for supporting this state in hardware on blade servers. Many server chipsets don't support S3 and even if they did, blades don't have the room to add a dedicated regulator to power the memory subsystem during S3. The StopClock (S1) state can be used and described to the operating system in place of S3 state. The advantage of this solution is that we can now support desktop OSs on BladeCenter platforms, and possibly other server platforms, even when the chipset doesn't support S3 state.
Suspend to RAM (S3) support for chipsets that don 't support S3
Customers who choose to install a Windows Operating system on their BladeCenter servers usually require that the BladeCenter server show proof that the operating system is supported on that server model. Some customers would prefer to install the client versions of Windows operating systems, such as Windows 2003 XP, because they are cheaper than the server versions of the same operating system. Operating system support is shown by applying for and achieving a Windows Logo of support, and part of the logo process is to pass a Windows Hardware Compatibility Test (HCT). Each operating system may have different requirements for the client and server versions that would prohibit a particular server's ability to achieve a Windows support logo. The HCT is different for each operating system and has different tests for various functions that the operating system uses. One such test is for power down/suspend states that the system must support.
During power up of a blade server system, or any server for that matter, the systems BIOS must communicate to the operating system which ACPI power states the system will support. Currently Server systems need only to support the Stop Clock (S1) state for logo requirements of both client and server versions of Microsoft operating systems. However, starting in 2005 server systems that wish to achieve client logo must support the Suspend to RAM (S3) state. The system tha...