Windows gone into snail mode?

[ColinJ]

Has your Windows computer suddenly slowed down dramatically and you don't know why? My laptop did and I have just found out what caused it and have sorted it out. What I discovered may help some of you, so here's the lowdown!

I'm not talking about slowing due to hardware faults, or running stupid numbers of programs at once, or viruses/other malware, or lack of memory ... Just a sudden and dramatic slow-down which rebooting does not fix.

My laptop slowed down so much that it was taking over 2 minutes to hibernate when I closed the lid, rather than the 15-20 seconds that it normally takes. It was so busy doing something at boot-up and shut-down that the associated Windows notification tunes came out horribly distorted, as did any other music that I tried playing on the computer. Videos were stalling, even when the content had been buffered. It was busy doing something, but what?

I loaded the Task Manager (TM) and it showed that the CPU was 50% busy. You would think that left 50% free, but I have a dual core processor so 50% pretty much means that the first core was running flat out, and the other core doesn't seem to help much when trying to run most ordinary Windows programs. The thing is - TM did not show a process hogging the CPU time ...

I found Processor Explorer on the Microsoft website (link) and that is a much more sophisticated tool for finding out what a Windows computer is up to. Using it, I discovered that interrupts were occurring at such a rate that the computer could barely keep up with them. Why?

A bit more Googling led me to the answer ... An apparently daft decision by Microsoft to permanently throttle back drive access speeds if more than a small number of errors are encountered on the system. This happens without any obvious warning being given. Once the software has been nobbled, it stays nobbled!

Technically - if 6 DMA errors occur, then Windows starts falling back to slower modes of access until it ends up with the ancient and very inefficient PIO mode. Once there, it stays there. PIO mode will kill the performance of the computer. You need to get it back into DMA mode.

Anyway, enough of that ... this webpage explains it all, and what to do about it. My laptop is now back to its old nippy self, audio sounds undistorted again, and videos no longer stutter and freeze. Boot-up, hibernate and shut-down times are back to normal.

I hope that helps!

 

[ColinJ]

Ha - the plot thickens! I've used the laptop a lot during the past 24 hours and it worked at full speed but it just slowed down again for no apparent reason. I checked and it had reverted to PIO mode again. So ... why is my hard drive playing up? It passes all the diagnostic tests that I have thrown at it. More investigation required, but in the meantime the fix worked again.

 

[MrJamie]

You can probably get a registry fix to make it less sensitive to CRC errors, but I'd be more inclined to think that you're fixing the symptoms rather than the problem. Definitely time to start backing up anything important me thinks

 

[ColinJ]

You can probably get a registry fix to make it less sensitive to CRC errors, but I'd be more inclined to think that you're fixing the symptoms rather than the problem. Definitely time to start backing up anything important me thinks

There is definitely something causing the errors, but the drive has passed all the tests that I've run on it. (And so has the system memory, the cache memory etc.) I will keep digging until I work out what is going on.

I should do a backup of the laptop anyway. I haven't used my desktop PC since I got ill in July and my backup drive is still connected to that!

 

[MrJamie]

You could check history of updates since you noticed it got really slow, incase a windows/driver update has made something bad. If it were a desktop i'd be suggesting trying different cables and messing around with drivers.

The hard disk diagnostics tend to give a yes/no answer, so AFAIK they rely on thresholds to decide if things are broken, perhaps they say the drive is still within normal parameters (sounds a bit star trek?) but it's still throwing up enough CRC errors to trigger switching to PIO mode. I think you'll be able to change a registry entry somewhere so that it takes more errors to switch modes, but im not sure if its a sign the disk is dying or just ageing.

I've had a nightmare with hard disks just this week and they can be a pain in the bum to diagnose, with possible problems from memory, power, board etc. My newish SSD would run fine alone as it did for months, but if paired with another drive (i tried a few) it would fail in windows and sometimes neither would be detected in BIOS. Drivers, reinstalls, firmware upgrades, underclocking, different cables/psu etc, then ended up deciding it was a good time for a mobo/cpu upgrade and its happy as can be

 

[ian turner]

so the smart check in speedfan isn't throwing up any warnings after online analysis then ?

 

[ColinJ]

I ran fan speed tests, temperature tests, all sorts of memory tests, anti-virus and malware tests, disk read/write tests, SMART tests, loads of other tests that I can't remember now ... Nothing threw up any problems.

What I have experienced recently is an occasional BSOD, sometimes with a mention of atapi.sys which might be a clue given what that does. I used fc to compare the installed version of atapi.sys with another copy that I have elsewhere and they are identical.

I can't find more up to date drivers than the ones that I have.

I have loads of free hard disk space and don't have a CD or DVD drive connected.

I use AVAST a/v software.

For now, I have a quick fix for the symptoms, but I still want to find out why this problem has started manifesting itself recently.

 

[ian turner]

Anything in the system logs ?

 

[ColinJ]

Anything in the system logs ?

I got distracted by a phone call and forgot to check.

Hang on ...

Oops - Bad block errors, paging errors, and timeouts!

I'll be back ...

 

[ColinJ]

Clusters containing the Java cacerts file were corrupted. Everything else is supposed to be okay so hopefully fixing the bad clusters will stop my disk problem coming back.

At some point, I'd like to replace the HDD with a SSD but I'm still concerned about the reliability of them.

 

[RussellZero]

Ssds are great but you need to treat them as if you expect them to fail sooner or later. I still use them, but I do make sure I backup everything on them regularly, 2 have failed on me in the last couple of years, and when they go they don't tend to give you any warning like y do with hdds. So my ssd is the windows boot drive, makes everything start up and run quickly, and my data and documents I keep on an hdd. I keep my source code on the ssd also to speed up big builds, but ensure I always backup to source control on a regular basis.

 

[ColinJ]

Ssds are great but you need to treat them as if you expect them to fail sooner or later. I still use them, but I do make sure I backup everything on them regularly, 2 have failed on me in the last couple of years, and when they go they don't tend to give you any warning like y do with hdds. So my ssd is the windows boot drive, makes everything start up and run quickly, and my data and documents I keep on an hdd. I keep my source code on the ssd also to speed up big builds, but ensure I always backup to source control on a regular basis.

I don't know if the laptop has room in it for two drives but I don't fancy that approach anyway. The main reason why I would prefer SSD is so I'd no longer be worried about knocking the laptop when the HDD is in use and damaging it***. I've known a few people who have suffered that problem, including my niece. I saw her tossing her laptop down onto a sofa after checking Facebook and warned her of the dangers of being so rough with it. She ignored what I said and carried on doing it. The laptop HDD died about a month later and she was charged over £100 to have it replaced!

I'm using my Galaxy Tab to make this post and love the fact that it is so rugged. (It also taught me that the laptop's 1.5 kg is a bit too heavy for comfortable portability wheareas this Tab's 0.5 kg is more like it.)

*** I wonder if that's what damaged the block on my laptop's HDD? I am careful with it but I literally do use it on my lap, and the occasional knock is inevitable.

 

[ian turner]

Unlikely. Using a laptop on your lap is more likely to damage your reproductive capability(overheating) than the harddrive, they're rated for drops of so many feet.

 

[ColinJ]

Unlikely. Using a laptop on your lap is more likely to damage your reproductive capability(overheating) than the harddrive, they're rated for drops of so many feet.

That wouldn't bother me because I don't intend to reproduce! I do find the heat a bit much though, so I sit the laptop on top of an A4 notebook (the paper/cardboard kind).

I know that laptop HDDs are supposed to be ruggedised, but as I mentioned above - I know people, including my niece, who trashed their drives by being a bit rough with their laptops while the HDDs were in use.

The laptop is working well today, but I won't really know for sure that the problem is fixed until I've had a few weeks without any further problems.

Incidentally, I checked the price of 60 GB SSDs and they are now as cheap as the Toshiba HDD that I currently use. I'm thinking of buying an SSD plus a USB drive enclosure such as this one and using the HDD in that to back up the SSD.

 

[ian turner]

Your neice was dropping her pc a few feet or throwing for that matter. Ipods don't keel over if you go jogging with them (the older harddrive based variety)