Resuming Windows 7 from Hibernate after a RAM change?

I ordered a pair of new DDR3 RAMs, I will install them to the empty RAM slots once they arrive.

What would happen if I hibernate my PC, then install the new RAMs, and then wake it up from hibernation? Would the system give an error message, or would it wake up alright? Do I need to shut down my PC before adding the new RAM units?

Of course, restarting PC after such a critical hardware change is important and affordable; and I will definitely do so. But I'm just curious about this, I am asking this question out of curiosity. I want to learn how the system would behave if I were to not restart it.

OS: Windows 7 Ultimate x64 SP1
Mainboard: Gigabyte P55A-UD3R, rev 1.0
RAMs: DDR3, 1333MHz

hkBattousai

Posted 2013-02-18T21:42:00.857

Reputation: 2 711

I honestly don't know what will happen - but if it were me, I wouldn't try it while anything important was running. I doubt it'll have trouble addressing the memory (after all, you're doing a full POST) but it may throw the unhibernate routines for a loop.

I think you should experiment with this yourself if you don't get a quick answer - in fact, I'm willing to throw some bounty karma your way if you do because this is neat. – Shinrai – 2013-02-18T21:45:28.297

9Shutting everything down is A Very Good Idea<sup>TM</sup> It's not one of those hotplug changes. – Fiasco Labs – 2013-02-18T23:50:50.047

1Easy enough to try with a VM and see. – ckhan – 2013-02-19T03:46:06.033

@ckhan - Adding hardware to a peice of electronic that is plugged into a voltage source is a HORRIBLE idea. How exactly would a VM help? – Ramhound – 2013-02-19T13:14:55.917

1@Ramhound The goal is to see how Windows reacts to suddenly having more RAM (ie. when waking up from hibernate). A VM would be a perfectly valid way to experiment with this. – Burhan Ali – 2013-02-19T21:58:47.423

2@FiascoLabs this is not about plugging RAM into a running PC, but about the reaction of a hibernated OS. – gronostaj – 2013-02-20T08:06:30.907

@BurhanAli - You can't change the memory settings on a suspended Virtual Machine. Its still a bad idea to plug in a ESD senseitive object into another ESD senseitive object while the ESD senseitive is plugged into a power source. – Ramhound – 2013-02-20T11:56:39.160

1@Ramhound Good point about the VM. The other thing is technically correct, but a hibernated machine can be unplugged from the mains power. – Burhan Ali – 2013-02-20T14:55:51.120

@gronostaj - it's about loading a memory snapshot into a changed memory environment, so the original statement still holds true. Bring the system down for a hard reboot. So shutting everything down, yada yada, yada – Fiasco Labs – 2013-02-21T02:24:36.950

Its still a bad idea to plug in a ESD senseitive object into another ESD senseitive object while the ESD senseitive is plugged into a power source. Re-read the question; they are not asking about adding the RAM while the system is in standby, they are asking about adding the RAM while the system is in hibernation. When you hibernate a system, it turns off completely. It writes the RAM to a file on the drive, then goes to S5 just like a regular shutdown. You can't change the memory settings on a suspended Virtual Machine. Not if it’s in standby, but you can if it’s hibernated. – Synetech – 2013-11-15T18:57:44.497

Answers

You will get an error message from the Windows Resume Loader on restart. You will get this nasty warning:

Your system's memory configuration has changed since it entered hibernation. If you proceed, the data needed to resume from hibernation will be lost. To preserve this data, turn off the system power, restore the orginal memory configuration and reboot the system. Otherwise, press to delete restoration data and proceed to system boot menu.

If you continue without restoring the original memory configuration, you will get roughly the same affect as if you had removed power suddenly rather than hibernating.

David Schwartz

Posted 2013-02-18T21:42:00.857

Reputation: 58 310

I did add a ram module to my notebook which i forgot that it is hybernated state (battery on) and now i have random system locks when entering vlc full screen mode. I didnt check if it is a module issue or motherboard issue but generaly it is a bad idea since you have power on the board. – Hasan Gürsoy – 2020-02-19T22:51:58.713

5Did you try it? – Louis Rhys – 2013-02-19T06:19:16.233

6Why would I bother, I've got better things to do with my time. And understanding what happens during a hibernate save, trying it is like sticking a hairpin in a power outlet, from experience of similar situations, we already know the results. The hibernate snapshot is not being restored to the same memory configuration, the OS dumps it and starts from scratch. – Fiasco Labs – 2013-02-19T08:04:13.660

I would also ensure that the computer is unluppged (or battery removed), as there otherwise will be some power in the system (stuff like WOL, keyboard wakeup, etc). – Holger – 2013-02-19T08:42:20.830

1@Holger - I install DIMMs routinely with mains power connected and have never had trouble. (I know, it is bad form for the reasons you mention, but...) – Shinrai – 2013-02-19T15:15:43.937

2@Shinrai Sure it will work, but there is a risk and I just wanted to point that out. I've also changed a lot of stuff without wearing a antistatic wrist strap, but once day I'll probably break something :) – Holger – 2013-02-19T15:29:21.640

I know that this is an old thread, but for that ones that are curious: Windows was hibernating and i disconnected it from mains voltage. I added two RAM modules that are exactly the same as the ones I have already built in. After connecting my PC to the power and booting Windows 10, it decided to restart completely. From there on I had a fresh rebooted system with 32 GB of ram.

I hope I got the answer people like me are asking themselves.

Salanio

Posted 2013-02-18T21:42:00.857

Reputation: 11