PSU that goes into sleep mode with cpu/mb?

[HFC]

Does PSU that goes into sleep moCPU/MB exist? All PSU that I have seen still have fan running after the CPU went into sleep mode.

 

[mpilchfamily]

There is no such thing. The PSU only supplies the power a system needs. So a 600W unit isn't constantly supplying 600W. So when things like the CPU go into sleep mode they use less power. So there is less power coming from the PSU. If you want to save more power then you need to just shut the system off.

 

[AmberClad]

I personally haven't noticed that the PSU fan still spins after the system is put into sleep mode...

 

[mpilchfamily]

PSUs will very. Some units actually shut off the fan if the temps are low enough. But the PSU fan needs to stay on to keep the PSU cool. Most PSUs just slow the fan down but never turns them off.

 

[SerpentRoyal]

All modern high-efficiency PSUs should default to the lowest power savings state after PC shut-down. Most will draw about 1.5 watt or less (standby power and logic circuit). Some boards will come with standby LED, which may draw an additional 2 watts.

 

[MetaDFF]

Originally posted by: HFC
All PSU that I have seen still have fan running after the CPU went into sleep mode.

Are you sure you are in the right sleep mode? Computers have two sleep modes, S1 and S3. In power state S1 everything is pretty much still powered on. S3 is the real sleep mode where the computer will power down everything (CPU and HDD) including all the fans (both system and PSU).

If you are using Windows XP there is a bug in XP where if you do not enable "ACPI suspend to RAM" during your Windows installation it will not enable S3 power state (thus PSU fans stay on even in sleep mode). The only way to fix this is to use an undocumented Microsoft utility called dumppo.exe to enable/force the computer to use the S3 power state.