What is causing my laptop slowdown?

March 10, 2007 10:52 PM

I'm having problems with my Dell laptop regularly overheating and causing everything to slowly freeze up, but I can't figure out the causality...

I seem to be running into problems with my Dell Inspiron 6400/E1505. It's 1.6ghz Intel dual-core. I try my best to not block the areas with the most heat: I'm usually using it lying down on the couch with the laptop on my stomach or sandwiched between my knees when the temperature rises, but it never seems to drop under 113F. I've got a fan-powered cooler mat coming in the mail, but I wanted to make sure THIS was what was causing problems:

The problem is that everything seems to grind at a halt (emulators slow down to 10-15%, video stutters and loses track with audio, mouse becomes very slowly responsive) at random intervals, which is what I got a dual core to specifically prevent. I've been trying to replace my most frequently-used programs with similar ones that have hyperthreading (more on that below), but it doesn't seem to be much help.

Once in a while, if I'm running Firefox and vlc (which I downloaded specifically because it splits the decoding of the video onto two separate threads) or any other set of cpu-intensive programs, the temperature spikes and everything grinds to a halt. I'll use a 3rd party fan control program to raise them to max speed and either flip the laptop over or hold it up until processor usage drops, but I'm not sure about the causality: is the temperature spiking and slowing down the system because of the programs? or are the programs being slowed down because I happened to have blocked an air intake with my leg or because it's laying on the couch?

posted by griphus to computers & internet (15 comments total)

Are you sure that the air's path within your laptop is not obstructed? Maybe there's too much dust covering the pieces in there.

A friend of mine had success with using compressed air once, but you might also consider opening up the machine to make sure.
posted by redteam at 11:45 PM on March 10, 2007

You don't give your OS. I have a 1.8GHz Latitude D600 that lives on a simple 'laptop desk', no cooling or anything fancy. It is up and running almost 24x7x365 for the past few years. I run Linux, and almost every single time that I've seen a "slowdown" event, it has been Firefox. Or most likely some of the Extensions I have loaded in Firefox. Whatever OS, next time you notice it going weird... run whatever process monitoring program and check what is using the most resources. With Linux, it's the 'top' program. Almost every time I notice any slowness, I run 'top' and Firefox is doing something strange. I kill Firefox and start it up again and all is well.

Otherwise, a 'laptop desk' will help with the heating issues. And a can of compressed air to blow any dust out of the fan will do wonders. Unless your Inspiron 6400/E1505 is vastly different, or you are doing CPU heavy tasks for a long time, heat shouldn't be that much of an issue. It's more likely that some program is hogging the CPU and disk and causing the slowdown.

I do a lot of movie watching with Mplayer, lot's of compiling and other CPU intensive tasks, but my bizarre slowdowns are always Firefox (or sometimes Gaim). Kill that bad process and your laptop will be happy.
posted by zengargoyle at 12:03 AM on March 11, 2007

When I took my Inspiron 8200 apart for the first time, I was quite shocked to find that there was no form of thermal transfer compound between the surface of the CPU and the surface of the fancy-pants heat-pipe heatsink. Since I applied some, my fans come on much less often and much less noisily.
posted by flabdablet at 12:09 AM on March 11, 2007

Do you notice a difference if your laptop is plugged into AC power or running off battery? There are a lot of power management strategies operating when your machine is running on battery, that don't have to operate when you're connected to AC. Whole parts of your CPU are shut down when not immediately needed on battery power, and your CPU clock is dynamically altered to low effective frequency, in an attempt to maximize battery life, and reduce heat creation. Your cooling fans also operate on a less aggressive profile when running on battery. So, plug it in, and check you power management settings, to see if your problems are alleviated by less restrictive power management policies.

And +1 on what flabdablet said. Dell's don't enjoy the best build quality, in my experience.
posted by paulsc at 12:24 AM on March 11, 2007

Thanks for the advice, flabdablet, I think I'm going to get some thermal grease and stick it on there. I've read about that in a couple of places and it actually sounds like that could be the exact problem (fans constantly on, physical processor abnormally hot, etc.).

It's actually plugged in about 95% of the time. I'm pretty used to desktops which is why I haven't taken the thing apart to give it a solid cleaning yet: I have no fear going into a desktop, but these laptops with their tiny, dense parts scare me a bit.

How hot is a (dell) laptop supposed to get, anyway?
posted by griphus at 12:27 AM on March 11, 2007

i8kfanGUI

I'd look into this program. I run it on my dell laptop, it lets you customise when the fans come on and off, and how fast. My laptop is definately running cooler since I got it.
posted by chrispy108 at 3:14 AM on March 11, 2007

might want to check out processexplorer. it will allow you to see exactly what is eating up the cycles on your cpu.
posted by sophist at 3:45 AM on March 11, 2007

Here's a link about overheating problems with Inspiron laptops, and Dell's legal problems because of it.

Be careful with the thermal compound. It will make the problem worse if it is not applied correctly. I would just try cleaning out any dust with a can of compressed air first.
posted by 14580 at 5:42 AM on March 11, 2007

I remember that I read somewhere that it helped a guy with a similiar problem to keep his DVD/CD ROM drive open all the time... ;-(
posted by yoyo_nyc at 8:48 AM on March 11, 2007

chrispy/sophist - i'm actually running both, and they have definitely been a help, but occasionally the whole system will be very, very barely responsive and cause me to be unable to get to either one.

14580 - sadly, my build isn't one of the ones under the scope of the settlement, or then new lawsuit. any guides you would personally recommend for applying the thermal grease?
posted by griphus at 3:02 PM on March 11, 2007

When my 600m started running hot, I blasted it out with Dust Off. A big dust cloud came out through the keyboard. After that, it ran cooler (but still warm). Now I blow it out every 2 months.
posted by dws at 5:37 PM on March 11, 2007

For hints about applying the grease, just Google "how to apply thermal paste"

Applying thermal paste is not that hard on a desktop PC. But I might be a little nervous about taking apart a laptop. Just remember to clean off the old compound with alcohol or acetone. Also, the compound is meant to fill in any gaps between the CPU and heatsink. You don't want it where you already have good metal-to-metal contact. That's why it needs to go on in a very thin layer - so it gets squeezed out from the areas where it is not needed.

BTW, the others might be right about the high CPU load of some of the processes that you're running. Is your CPU speed adjustable? Can you turn it down from "Max" to "high" or "medium" or whatever? It's going to take you longer to compile stuff, but your laptop may last a lot longer.
posted by 14580 at 6:38 PM on March 11, 2007

I did some more searching and I found lots more information about overheating problems wtih Dell 1500 series laptops.

I only read a few pages, but many people seem to claim that cleaning the dust off the heat sink helped a lot. Others have found that their fan(s) are not working as well as they're suppose to.
posted by 14580 at 8:00 PM on March 11, 2007

The dust in the heatsink thing is real, at least if your Dell uses the same cooling system as my old Inspiron 8200. It's not a simple chunk of aluminium with fins like you'd find in a typical desktop; it's a square block of copper with a heatpipe coming out the side, and a whole heap of really thin fins on the end of the heatpipe near the fans. These fins are spaced maybe 1mm apart, and are positioned on the upwind side of a couple of little fans. There's a vent on the top side of the case, right above the fins, and another little one on the side; when the fans are off, warm air comes out the top vent by convection. With the fans on, air is drawn in through both top and side vents, and expelled by the fans on the rear of the casing.

It doesn't take much dust and hair to clog fins spaced 1mm apart, and because the fins are upwind of the heatsink and have intake air fed from multiple directions, there's never a forceful enough airflow through the fins to shift any dust that does build up. If you peek into the back of the case past the fan blades, and you see any dust at all on the fins, you can bet there's enough there to reduce their efficiency quite a lot. And if you've been using your laptop mainly in your lap, there's probably a fair bit of clothing fibre sucked in there.

So the first thing to try, before you even take the case apart, is to purse your lips and blow in through the fans as hard as you can. If a large puff of dust comes out through the vents when you do this, I'm betting your machine will then be back to running basically like new.

If you do find that your cooler has been clamped "dry" onto the top of your CPU, and you decide to go with the thermal grease, do be careful; as 14580 says, you can actually make things worse this way. Use a reputable brand (Arctic Silver is supposed to be pretty good), don't use too much (you don't need more than about a match-head-sized blob) and spread it in a way that won't cause bubbles; I always just put a small blob right in the middle of the CPU, push the heatsink straight down onto that, then smoosh it around in place to spread the gunk before doing the final clampdown. If you feel a need to take the heatsink and CPU apart again after the smooshing to see if your technique has been effective, clean it all off and start over afterwards. Bubbles in your heat transfer paste can make hotspots on your CPU that won't necessarily be picked up by its internal temperature sensor.
posted by flabdablet at 9:04 PM on March 11, 2007

I don't know if anyone is going to come back and read this, but I blew some air into it and am running the cooling mat at high speed regularly. I actually managed to get, on average, almost a 20 degree drop in certain situations: high load used to be 140+ is now 120 and regular runtime went from 120 to about 110, and even under 100 when I manage to get the laptop into somewhere with decent air circulation for all the vents. Thanks guys!
posted by griphus at 6:48 PM on March 17, 2007