The system firmware has changed the processor's memory type range registers (MTRRs) across a sleep state transition (S4). This can result in reduced resume performance.

You may want to disable "Allow hybrid sleep" in Power Options

Yes ... of course .. it has to do with your hardware ... that's why so many people with completely different hardware are having this problem.... that's why it has happened to me with several different hardware combinations including different motherboards, different video cards and different drives.... that's why it can happen with Intel and AMD motherboards from all major motherboard manufacturers...desktops and laptops.

Sorry, this is not hardware related and this issue has been around for at least 10 years, in my research of this problem, I have seen complaints about it from people using Vista. I have had this issue (or first noticed it) since Windows7 (and again my hardware has changed over those years and the problem persisted) 

My old system that had this issue with Windows shows no issues, no errors at all with sleep modes in Linux. Linux's sleep states all work fine with no logged errors so the hardware is fine.

Chances are, since this doesn't seem to effect the actual computer's performance, it's most likely some mis-triggered, generic information that is poorly worded or has nothing to do with the actual situation like a lot of other messages the log files spit out. As I said before, Microsoft just needs to go in and remove this trigger from being logged since they can't figure out what is causing it for so many years and it doesn't really effect the computer's functionality.

The only "work around" is to ignore it and try not to get annoyed that you have to skip over them to see any real issues. At least the logs are set to a size  and wont get "too big" with all the unnecessary errors.

This is a general reply to everyone who's contributed to this thread.

To me "system firmware" in the logged error message means the BIOS, so not sure blaming MS will help as typically hardware manufacturers together with their BIOS partners are responsible for ensuring the BIOS works correctly.

I'm seeing this error logged on a fairly old Toshiba Satellite L300-25H (Intel T6200 processor) that's been upgraded with a Kingston 120GB SSD and Windows 8.1. This machine doesn't support IRST (Intel Rapid Start Technology) so that solution doesn't apply in this case.

I doubt I could get Toshiba to update their BIOS for such an old machine (it's a long since discontinued model), so looks like will have to find a workaround...

Thanks for your posting. Interesting. I am guessing too that this is not a serious "error". I am guessing also your summary of the history of the "problem" and Microsoft's unwillingness or inability to do anything about it just about nails it.

Steve

what type of crashes are you getting? .. this error doesn't cause any noticeable issues other than the one error in the logs every time your system wakes from sleep or hibernate.

Your crashing may have to do with something else. I had major issues with sleep on my system. It turned out to be my Ceton InfiniTV card. I was able to finally determine the issue and stop the system from crashing when in sleep "or coming out of sleep".