i5 2520m stuck at 800mhz

Hey guys, tried to watch a movie on my x220 today and it was really choppy. Opened up CPU-z and found out that the cpu was stuck at 800mhz. The laptop is plugged in and I'm on maximum performance profile. Help?

 

Which player were you using? Does it have GPU acceleration?
I'd think 800MHz on two cores should be enough except for maybe 1080p.

 

Could be a heat issue. Does the laptop feel hot?

 

Did you take out the battery while watching the movie?

 

With my T420, the need to go above 800MHz doesn't really start until a movie is 720p or above. Even at 720p, it doesn't necessarily jump in clockspeed.

I'm streaming an episode from Batman: The Animated Series wirelessly from a network drive at the moment. If I only have that open, it stays at 800MHz. If I type fast enough in Firefox while posting this, the CPU briefly jumps to 2.9GHz, but drops back down quickly if I stop typing.

 

I don't mean to sound condescending at all, but sometimes it's the simplest thing that is overlooked. Is there any chance you might have changed the cpu setting of the maximum performance profile?

 

If you took out the battery while plugged in this could cause issues as has been reported on this forum.

 

I'm using VLC

Nope, doesn't feel hot, and TPFancontrol report <50C in CPU temp.

Yes, the battery is out. Does this matter?

But the video is very laggy though. You'd think the CPU would ramp up to ensure smooth playback.

It is under max performance setting.

Never read about this before. Let me try w/ the battery in.

 

Wow, plugging in the battery totally fixed it. Never knew that taking out the battery would make the laptop get stuck at 800mhz.

Thanks for the help guys! Is there any way to make it run at full mhz w/o the battery when plugged in? It'll be plugged in 85-90% of the time, so I don't want to overcharge the battery unnecessarily.

 

Not really; the system isn't designed to run without a battery.

You can stop charging the battery at a desired level by using Power Manager's Advanced state under the Battery tab, under battery maintenance.

 

As Colonel O'Neill said, set charge thresholds in Power Manager, rather than removing the battery. This will accomplish the same thing.

 

I wish there was a windows setting that had the ability to do that. It is the only reason I'm thinking of installing power manager. My selective ocd tendencies has me wanting the least amount on the computer as possible.

As far as taking the battery out. Ha, I was doing the same thing for a few days... wondering why it was stuck at 797. My old laptop never had the issue so I never thought of it.

 

What percentage should I set it to?

 

There's some debate about that, everyone has their opinion. I have mine set to charge at 85% or lower, and to charge back up to 95%. In my case, I use AC most of the time.

 

I'm glad I found this thread. I've been using thinkfan to lower the fan (thus raising average cpu tmp by 7-10c).

I didn't know why my x220 got stuck at 800MHz until I found this thread. I think there's a reason for removing battery though. Li-ion battery degrade faster under warmer environment. -- With x220 plugged in all the time, and CPU fan running at lower speed, I suppose my battery will degrade faster than normal.

Too bad I can't program charge level in Linux.

 

Tp smapi - ThinkWiki

https://wiki.archlinux.org/index.php/Tp_smapi

Don

 

If you are going to be plugged in, I'd leave the max charge at around 45%. I personally have it set to charge at 38% and stop at 42%. Though, I take the battery out as my W520 runs fine without it (Turbos all the way up to 3.4GHz on one core, 3.2GHZ on two cores, and discrete GPU runs normally).

 

I never remove the battery, but because of this thread I checked what'd happen. It does throttle to 800mhz with the 65W adapter, but if you use a 90W it runs at full speed.

 

Thanks for pointing that out Don! I thought I searched carefully, but obviously not careful enough.

One problem though, I can seem to modprobe tp-smapi on Ubuntu Natty. tp-smapi-modules-xxx and tp-smapi-dkms installed. But I got this when I try to load the module :

Maybe there's a hardware/firmware change on the x220?

 

Do you think it works this way by design or accidentally? -- It seems odd to me though. If power supply is an issue, I'd rather run CPU at lower frequency with 65W PSU just to have enough power to run the machine AND charge the battery.

 

I'm pretty sure previous models have behaved this way on a 65W adapter. Either way, I don't know why anyone is removing the battery. Mine is currently at 28C, not charging. I use the 90W in my main workstation because it charges the battery faster.

 

I assume 28C is battery temp right?

 

Yep, battery.

 

Interesting. I checked my T420s charging using both 65W and 90W PSUs and they both charged at about 26W. However, it is plausible that if I was also heavily loading the T420s then the charge rate would reduce because the combined requirement would exceed the output of a 65W PSU.

John

 

See this thread:

tp_smapi 0.40-9 incompatible with thinkpad w520 - Linux Archive

Don