Stuck at 1.2 GHz after resume from hibernate

I ran into this problem on my work laptop last week, and haven't figured out quite what's going on. Essentially, after resuming from hibernate, it was stuck at 1.2 GHz. It has a Core i7 3520M processor (Ivy Bridge) that normally runs at 2.9 GHz, so this is significantly slower, and it was very noticeable. The frequency was measured with CPU-z, and the sluggishness and low temps for 100% CPU usage in HWMonitor confirmed that the processor was not running as fast as normal. Rebooting solved the problem. But at 1.2 GHz, the laptop was slower than my 2007 laptop.

My question is, what may have caused this, and what remedies would y'all recommend? I'm thinking RightMark CPU Clock Utility and ThrottleStop may be good options to try to fix the problem without rebooting? (Rebooting isn't ideal since I often leave things up to resume the next day, and rebooting is fairly slow on this laptop) Has anyone else encountered something like this? It appears that 1.2 GHz is the processor's minimum frequency.

The other oddity about this laptop is that sometimes when resuming from hibernate, it will display on the external monitor, but will not display anything on its own monitor. The monitor appears to be completely off, and is not detected in Windows' Display Resolution page. This isn't quite as bad, as it's more or less avoidable by not plugging in the external monitor until the resume from hibernate completes. It's also solvable by rebooting, and sometimes solvable by hibernating and resuming again. Suggestions on causes for this are welcome as well.

Specs:

Dell Latitude E5530
i7 3520 (2.9 GHz, Hyperthreading)
8 GB RAM (1600 MHz, Hyundai Electronics)
Intel HD Graphics 4000
320 GB, 7200 RPM HDD (yes, it would benefit from an SSD)
1920x1080 matté screen
Windows 7 Professional x64

 

Have you checked whether your BIOS was up to date. If it isn't, I would check in the update notes of the versions that came after if there is anything describing that kind of behavior that was fixed.

Other things I can think of for the video issue is to make sure you have the latest drivers available from Dell for the HD4000 (which you probably did). If you have the Dell FEP installed, you could get rid of it and use the standard Windows power plans.

 

RightMark CPU Clock Utility is obsolete and does not support any Core i processors.

It's a common bios bug when resuming from sleep or hibernate that a couple of registers in the CPU don't get set up properly. ThrottleStop should be able to solve this problem.

 

Same issue with my desktop actually. Stuck at 1.6ghz rather than 3.8ghz because my overclock seems to not work.

I let my UPS put my computer to sleep at a certain time each night and turn it back on before I get home from work to save energy and when I encoded a video and saw it took 3x longer than normal I found the cpu speed was locked.

 

The BIOS I haven't checked, might see if that solves it. Good idea to check. The GPU drivers are up-to-date. I might try the standard Windows power plans; I did notice that Dell's Battery Status software is broken, so it's possible something else with Dell's power management is interfering.

I have found out that simply unplugging and re-plugging-in the computer after it has resumed gets it to unlock - today it was stuck at a 17x multiplier. That's a simple enough solution, though it would be better to solve it completely.

I didn't know RightMark was that completely obsolete. Probably since until a few months ago my newest laptop was Core 2 Duo. I'll try ThrottleStop on it if the BIOS update doesn't fix it (nice software, by the way... I've already used it on my 1520).

That's the sort of thing that happened when I noticed it. Seems more surprising on a desktop, but I suppose it probably isn't tested as much in that scenario, either.