Standby S3-state WHOA

[dpopiz]

whoa this is weird.

I just set my stanby state to s3 in the BIOS. I can boot up to win2k right back in my previous session in about 25 secs instead of 2 mins! This is too good to be true; I really think it is. My understanding is that in this state, ONLY the ram is running. I thought at first that it must be a little power constantly comming from the atx psu, but I decided to do a little experiment: I DISCONNECTED the power cable and reconnected it and bootted up. It came right back from standy! Is the RAM running off the CMOS battery? Isn't this a bad thing? I thought that I could just use standby in place of shutting down, but now I'm not so sure. Anybody know how s3 works?

 

[AppleTalking]

Well, if you pulled the power supply cable then it must have switched to running the RAM off the CMOS battery. Either that or there was some residual charge left over. How long did you unplug the cable for?

<shameless plug> Of course, I never use standby. I have my computers working for Team Anandtech 24/7! </shameless plug>

Nick

 

[dpopiz]

I definitely unplugged it for enough time because DRAM needs to be refreshed about every 50ms.

 

[Adul]

I thought standby data is writen to the HD. Anyways, the power supply can hold enough charge to maintain what the memory needs for a little while. It depends on the draw, power supply rating, etc..

 

[datallah]

There is no way your RAM is running off the CMOS battery. What is happening is that your system state is being saved to your hard drive and the power is being turned off. When it turns back on, it restores the system state so you can start back where you left off without rebooting (this is also called &quot;Hibernating&quot; and is very widely used in notebooks). The only disadvantage is that you are not really rebooting, so it doesn't give you a clean session.

 

[dpopiz]

noooo I'm not hibernating
I'm doing an s3 standby, which means that the memory is kept charged. It's even quicker than a hibernate because it doesn't really have to load anything from the hd.

 

[Gunbuster]

How long did you have it unplugged?

 

[Noriaki]

unplug the tower, then hit the power button, make sure the power supply is fully discharged. A power supply can hold enough charge to run your RAM for a while.

(I've done this, unplug, hit power, and all the fans in my system come on, there is enough power left to give the fan motors enough juice to start spinning...of course everything stops right away to, but the fans do a few 100 rotations at least).

After that, now you are sure your PSU is drained (give it another minute if you want to be anal) then plug it back in, and see if you can restore from S3. My guess is you can't.

 

[ElFenix]

i'm going to have to agree with appletalking, why suspend when you could be on all the time cracking for Team Anandtech?

 

[datallah]

OK... S3 is &quot;Suspend-to-RAM&quot; which means that waiting 25 seconds for it to reload is an aweful long time! It should restore it in under 10 seconds (at least it does on my a7v133) the only reason that it is that long is that the drives have to spin up.

I reiterate, there is NO WAY that the RAM is running off the CMOS battery, there just isn't this capability. The capacitors in the Power Supply can store enough current to keep the ram refreshed for a little while so that must be what is happening (You can see this effect on my board because if the PSU is unplugged from the wall, the green LED (meaning that there is still power to the RAM) on the board stays on for quite a while.

If it still stays on (or will restore) after you hold down the power button with the PSU unplugged, then you have a miracle on your hands and better call the press.

 

[dpopiz]

yeah, you're right....It is just running of the psu's capacitors

there are many reasons why I don't keep my comps on all the time:

1. I have 5 like this one
2. Cal is in an energy crisis
3. I stopped leaving my comps on all the time when I figured out that it means I don't have to replace psus, hds and fans, every 9-12 months

 

[randomlinh]

how exactly to you &quot;execute&quot; this so to speak after it's enabled?

 

[GL]

Son of a gun, Noriaki you're right. Cool, I guess that's why they tell people to never open up a power supply because you might get shocked!