From: nospam@needed.invalid   
      
   On Mon, 2/9/2026 12:52 PM, Carlos E. R. wrote:   
   > On 2026-02-09 15:02, Paul wrote:   
   >> On Mon, 2/9/2026 4:32 AM, Carlos E. R. wrote:   
   >>   
   >>> A desktop computer has no battery, so it can't really have sleep mode,   
   >>> so neither can have hybrid mode. Sleep with PSU running at a lower power?   
   >>   
   >> A desktop definitely has S3 sleep. The DIMMs are powered by   
   >> +5VSB, and that is the power rail which does not require fan cooling.   
   >> There are power converters, suitable for delivering the DIMM sleep voltage   
   value.   
   >>   
   >> If you plug in your Apple iPhone to charge it, into a charge port on   
   >> the back of the PC, that could overload +5VSB... and then your S3   
   >> sleep on the desktop could be lost (unless the Hybrid Sleep was enabled).   
   >   
   > I remember a computer I bought with Windows Me, long ago. It could go to   
   sleep, but the CPU burned to the touch.   
   >   
      
   Windows Me might have been APM (the scheme before ACPI), and then   
   I don't know what state that would be. Maybe a kind of Standby   
   rather than a Sleep.   
      
      https://en.wikipedia.org/wiki/Advanced_Power_Management   
      
         APM defines five power states for the computer system:   
      
         Full On: The computer is powered on, and no devices are in a power   
   saving mode.   
      
         APM Enabled: The computer is powered on, and APM is controlling device   
   power management as needed.   
      
         APM Standby: Most devices are in their low-power state, the CPU is   
   slowed or stopped,   
                      and the system state is saved. The computer can be returned   
   to its   
                      former state quickly (in response to activity such as the   
                      user pressing a key on the keyboard).   
      
         APM Suspend: Most devices are powered off, but the system state is saved.   
                      The computer can be returned to its former state, but takes   
   a   
                      relatively long time. (Hibernation is a special form of the   
                      APM Suspend state).   
      
         Off: The computer is turned off.   
      
   That's not a very detailed description.   
      
   It couldn't be a "stopped clock" (BCLK) because x86 CPUs have had   
   DRAM for internal storage of things. (Multiport SRAM for registers,   
   but DRAM of some sort for more bulk storage inside.) And then if   
   the CPU was expected to keep-state, BCLK still had to run to   
   arrange Refresh for the DRAM cells. The DRAM used fewer transistors, back   
   when transistor count mattered.   
      
   There were a few (non-Intel) CPUs which were fully static, and if you pulled   
   their BCLK-equivalent to Logic 0, the leakage was practically zero.   
   And those would be ice cold when parked. A number of those flew in satellites.   
      
   There wasn't really much power-saving back around the year 2000.   
   It took the video cards, for example, a long time to incorporate   
   power saving. The 8800 video card, its power save state used   
   50% of the 3D run-level power. A savings for sure, but not a   
   big savings. The very best achievement was video cards that   
   could drop to around 3 watts. The video cards today are   
   unlikely to be able to reach 3 watts. Their resting power will be   
   more than that (like 40 watts maybe, on the biggest card).   
      
      Paul   
      
   --- SoupGate-Win32 v1.05   
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