Diagnosing poor performing Windows laptop

March 18, 2013 10:15 PM

My Windows 7 laptop frequently goes to 100% CPU usage and becomes unusable. I've discovered that if I put it to sleep and immediately wake it up, the CPU usage goes back down to a reasonable level (10% ish) and stays that way, but this problem recurs at least daily. How can I diagnose and fix the cause of this issue?

It's a Lenovo Thinkpad Edge running Win7 64 bit, about 3 years old. Intel Core i3-330M 2.13GHz, 4GB RAM, 250 GB HDD (nearly full), integrated graphics. I tend to run an admittedly heavy load, browsers with a billion tabs open, Python and Javascript applications, Word, Excel, etc... but the CPU problem seems to happen at random times, even when there is not much open. Closing applications does not seem to bring CPU usage down -- only putting it to sleep and waking it up does. Physical memory usage tends to be about 50%.

This has been going on for at least a year to a noticeable degree. I did a fresh install of Win 7 some time ago but the problem recurred soon. Nothing in task manager seems to be causing this -- when it gets sluggish, applications that normally use 1% of the CPU suddenly need 15%. Just did a virus scan and it came back clean, though maybe I should check again.

I've thought of getting more RAM and/or an SSD but given the age of this laptop I don't know if I want to throw more money at it. But I would prefer to delay replacement for another year or two and I feel like that should be possible with this hardware. Contemplating switching to Linux but I recall Ubuntu having, um, CPU utilization issues (hmm) when I tried it a few years ago, though maybe it will be better this time. Or maybe this CPU is just underpowered?

Any ideas? How do I even figure out what's wrong? I am super frustrated.

posted by PercussivePaul to Computers & Internet (15 answers total)

Process Explorer is a really helpful (free!) tool that you can use to see what processes are running and how much CPU power those processes are using.
posted by littlesq at 10:27 PM on March 18, 2013

I've been working off and on in IT covering three decades now, and I've never, ever seen a problem that was fixed by putting a laptop into hibernation mode. Hibernation mode is the devil. Lucifer. Full stop.

Upon re-reading your description, I'm forced to think that your nearly full HDD with W7 on it is trying to overwrite a hibernation file to your system drive up until you "put it to sleep", and then it works moderately decent until that main drive comes close to running out of space. How full is the drive?

When you reinstalled W7, did you wipe the internal drive? Buy a cheap, external drive, dump all your data to it, wipe the internal one, reinstall W7, rinse and repeat.

Can we get a model number on that Thinkpad Edge? Your specs seem a bit out of date, but if you're not trying to do anything goofy, that laptop should still work pretty well.

All that being said, putting a nice SSD in a laptop will increase your responsiveness more than anything else in the computer world in the last ten or so years.
posted by Sphinx at 10:29 PM on March 18, 2013

Thanks Sphinx. Full model number is Lenovo ThinkPad Edge 14 0578-82U, purchased in May 2010. I am puzzled by the sleep thing too but there's no doubt that sleep reliably snaps it out of this mode.

I split the drive into 2 logical partitions, C:\ has 10GB free and D:\ has 3.5 GB free. Both NTFS. I keep all my media and data files and stuff on D:\ and for a while I was dual-booting and would mount that drive in Linux. When I reinstalled I wiped C:\ but kept D:\. There's also a 10 GB Lenovo recovery partition. Feel like perhaps this hard drive is a mess, huh?

SSD was my plan but I'm balking at the cost, since I find 256 GB gets filled rather easily but a 512 GB SSD is cost-prohibitive. Maybe I should bite the bullet (one or the other).
posted by PercussivePaul at 10:50 PM on March 18, 2013

There's a background task which is usually present on most Win7 machines which scans for malware. This is not "Security Essentials"; it's a parallel program. It doesn't run continuously, but when it kicks in it is a system hog.

However, it's supposed to be sensitive to other use, and suspend itself if it looks like you're using the machine. If it is what you're seeing, the right answer is to ignore it. It isn't doing any harm, and if you start using your machine it'll get out of the way.
posted by Chocolate Pickle at 12:08 AM on March 19, 2013

Any CPU newer than a Core 2 Duo is gravy for all but extremely specialized tasks. Your CPU model is not the problem. I routinely run heavy workloads like that on an AMD Fusion netbook without much trouble.

It sounds like it might be trying to page to a too-full hard disk. 10 gb free on C:\ is pretty low for a Windows box. I'd try to get that up to 20 gb as a first step. Keep your multitasking under tight reins for a few days, too.

If the problem seems to improve with more space on the system disk and less demand on the RAM, then your next steps should be to get a 512gb 7200RPM drive upgrade (or bigger, if that's what it takes to keep you from filling it to capacity) and to cram as much RAM onto your system board as it will support. Both reasonably cheap upgrades that are appropriate for a laptop in a midlife crisis.
posted by zjacreman at 12:34 AM on March 19, 2013

It sounds like a software issue, but it's never a bad idea to rule out hardware. Try booting from USB (preferably a fast USB drive). Does the problem still happen? Then you have a hardware issue.
posted by vasi at 2:21 AM on March 19, 2013

Maybe an overheating CPU is causing it to go into a low power mode? Hibernating is just giving the CPU a chance to cool down.

Install some software to monitor system temperatures (pick your poison) and check the readings when the slowdown occurs.

Fixes might involve tweaking fan settings in the BIOS, or opening up the laptop case and cleaning out accumulated detritus with compressed air.
posted by robtoo at 2:30 AM on March 19, 2013

And I hesitate to suggest this (because this isn't the 90s any more), but try cleaning out as much space as you can on the C: drive (ccleaner may help) and do a defrag. While you're at it, do the D: drive.
posted by robtoo at 2:34 AM on March 19, 2013

First of all, the people saying any system new enough to have a core i3 is "outdated" are ridiculous. For some reason I see that "anything older than two years is outdated" mentality way too much on Internet messageboards. The person saying anything core2duo or newer is gravy is spot on. 4gb of ram is also by no means "not enough". Windows 7 handles normal stuff, and even some light "more intense" stuff fine with 2, or even 1gb of ram. I regularly do "serious work" on slower machines than yours all around, and they still feel plenty peppy even compared to my brand new i7 machine.

I do on site service in peoples home offices and such, and I've seen the exact problem you were describing several times in the past year or so.

Every single time it was malware. You need to boot in to safe mode and do a scan with malwarebytes, and a serious virus scanner like nod32. Look through general checkup guides on sites like bleepingcomputer for identifying what infection you potentially have.

Unless the laptop is getting BURNING noticeably hot, I wouldn't suspect CPU throttling or any thermal issues. You would notice if that was going on. The fan would be running loudly, and the machine would be quite hot.

I would bet almost anything this is malware. The sleep/wake thing backs that up too. I swear I've encountered exactly that, I just didn't write down anywhere I can find now what exact malware had caused it.
posted by emptythought at 2:39 AM on March 19, 2013

I had this problem with an XP laptop. Many of the people above are trying to diagnose this as if there's some reasonable cause (e.g. disk thrashing) and I attempted to solve my problem the same way, to no avail. If you google "100% CPU at random" you will get lots of hits and be directed to forums where all sorts of solutions are suggested, often with the original asker saying that this one thing worked where nothing else did the trick. "Solutions" ran from malware removal instructions to registry hacking to changing chip settings in the BIOS and I dutifully tried each of these in turn and finally one of them worked. This was 2+ years ago so I no longer remember which it was (other than that it was a change to the registry). You could go on a hunt like I did. You may, with this question, already be on one. All I am doing is sharing my story so that you're less alone in the world.
posted by Obscure Reference at 5:17 AM on March 19, 2013

Sometimes it comes down to backing up all your stuff and reinstalling the operating system. It's a pain, but if nothing else works, you can at least see if, on a fresh install, it's still happening, in which case you can narrow it down to hardware, bios settings, or drivers.
posted by stavrosthewonderchicken at 6:58 PM on March 19, 2013

Virus and malware came up clean despite repeated scans. I began to suspect the display driver, since I realized that I often encounter this problem when putting laptop to sleep, attaching external monitor, then waking up. I've updated it (along with others) and so far I haven't noticed the problem recurring but it's too early to say. But I have also ordered a big SSD and more RAM and am going to do a fresh install, and am hoping the annoying problems go away after that.
posted by PercussivePaul at 1:50 AM on March 24, 2013

Okay, now running 8GB of RAM and a 500GB SSD and a few hundred dollars out of pocket but... holy hell, this old laptop is faster than any computer I have ever used. SSDs are the greatest thing in the universe. I did a fresh install, and whatever problem was there before is gone. CPU usage tends to hover at 5% or less. Hopefully won't need a new laptop for another couple of years now!

(the display driver was not the problem, issues still recurred)
posted by PercussivePaul at 6:16 PM on March 27, 2013

Okay. Problems recurred again and I was ready to curse the world but I found this post which suggests that the 65W power supply may be underpowered for when the battery is charging.

In 'sluggish mode' playing video the CPU usage climbs to 90%. The adapter is screaming hot. I unplug it, and CPU usage drops down to 10%. I was able to repeat this pattern several times. I'll order a 90W adapter and hopefully that will fix it.

I guess it makes sense. The behavior is consistent with overheating (such as hibernation fixing it), but CPU temperature was normal and laptop was not running hot, so I was stumped. It never occurred to me the power supply might be overheating. I guess it maybe drops the supply voltage which throttles the CPU, or something like that. Will report back again when I have a new power adapter...
posted by PercussivePaul at 11:30 PM on March 28, 2013

Follow-up, 90W adapter has arrived and the problems are now gone.
posted by PercussivePaul at 6:51 PM on May 1, 2013