Standy/Sleep mode, Power supplies and Fans

[frobnitz]

Folks, forgive me if I am covering old ground here, but I can't seem to find a good answer to this question, so I am venturing a new post.

I am getting ready to build a new desktop, probably a Athlon XP with the A7V333 (want to be prepared for the T-bred's when they come out), and want to be able to use the suspend/sleep mode in Windows XP with the ACPI support the system supports.

The question is do I need to get a specific power supply to support this mode of operation? I notice that Enermax sells supplies that specifically mention sleep support. I gather they provide a small amount of current to keep system state powered up, but the CPU in essence goes dormant. Do all supplies have this? I see no mention of this in the Antec documentation on their 350 and 400 Watt supplies.

Also, will the fans spin down during suspend mode, or go to an idle state? I know the A7V333 has this Q-fan feature which can slow down the fans based on temp, and with COP to protect the CPU, but the manual doesn't have a lot to say about it.

Thanks very much!

Frob

 

[HappyPuppy]

I can understand the suspend/sleep mode for laptops but, just out of curiosity, why do you want to use this feature on a desktop PC? Power savings wouldn't amount to anything to speak of. Just curious.

 

[frobnitz]

<< I can understand the suspend/sleep mode for laptops but, just out of curiosity, why do you want to use this feature on a desktop PC? Power savings wouldn't amount to anything to speak of. Just curious. >>



I would like the system noise to drop significantly, but still have wake on lan for backup and quick return from standby, which I don't think hibernation does. Not a big deal deal though...

Frob...

 

[hmsrolst]

I don't know the answer to your main question, but you're right about hibernation--it's quicker hibernating than shutting down, but starting up you still go through the full pre-Windows post, even though Windows is ready quite a bit faster since it's resuming rather than starting. It's a lot more time than standby.

 

[jaeger66]

Suspend to RAM is much faster than hibernation. Hibernation becomes slower as you add more RAM too.

To answer the main question, Standby is either S1(Power on Suspend) or S3(Suspend to RAM) depending on BIOS setting. In S3 everything will shut down except the RAM. In S1, the fans will all still spin. It's basically the same as just turning off your monitor, so S3 is what you want. It requires no special power supply.

One thing on Asus boards though, if you EVER boot to the OS with Suspend to RAM disabled in the BIOS it will never work again until you reinstall the OS, regardless of the BIOS setting after that. BIOS flashes disable it, so make sure you re-enable before booting after a flash.

 

[jaeger66]

<< I can understand the suspend/sleep mode for laptops but, just out of curiosity, why do you want to use this feature on a desktop PC? >>


Because having your PC "boot" in 10 seconds is very nice.

 

[frobnitz]

<< Suspend to RAM is even faster than hibernation. Hibernation becomes slower as you add more RAM too. >>



I've heard about STR before - this is very cool. I think this is how desktops may actually implement the stanby feature.

But getting back to the point of the post, does the PS need anything special to support this?

Thanks - Frob

 

[jaeger66]

As I said:



<< It's basically the same as just turning off your monitor, so S3 is what you want. It requires no special power supply. >>



The only time you might have trouble is with the cheapest of the generic PSUs, which could have a weak +5vsb rail(the rail that provides standby power).

 

[jaeger66]

<< I've heard about STR before - this is very cool. I think this is how desktops may actually implement the stanby feature. >>


How it's implemented depends on the BIOS setting. It's either STR or POS.