PC slow for no apparent reason

[goldtech]

Hi,

I realize my laptop is not homebuilt but I need expertise...

I am completely clueless here. My laptop has slowed to a crawl for no
apparent reason. It's as if the CPU itself has slowed, or acting like
it is starved for physical memory. The slowness is not on the OS
software level. Linux and XP are both slow. Booting is slow, bios
flashing is slow everything no matter what crawls. Video is slow.

I have a fast machine with 3gig memory.

What could cause everything to slow?
My HD checks OK on tests I've tried...I thought maybe the HD is on
it's way out. But there's not noise or excessive cranking.

What could it be?

Tried a reformat and reinstall. Reinstall was slow - took hours were
is usually takes about 1/2 hr...

Lee g.

 

[goldtech]

I should add. Everything works. All processes complete but at a
crawling speed. It's not like any function is overtly broken but
evrything crawls...

 

[Sjouke Burry]

Hi,

I realize my laptop is not homebuilt but I need expertise...

I am completely clueless here. My laptop has slowed to a crawl for no
apparent reason. It's as if the CPU itself has slowed, or acting like
it is starved for physical memory. The slowness is not on the OS
software level. Linux and XP are both slow. Booting is slow, bios
flashing is slow everything no matter what crawls. Video is slow.

I have a fast machine with 3gig memory.

What could cause everything to slow?
My HD checks OK on tests I've tried...I thought maybe the HD is on
it's way out. But there's not noise or excessive cranking.

What could it be?

Tried a reformat and reinstall. Reinstall was slow - took hours were
is usually takes about 1/2 hr...

Lee g.

Disk might have switched from dma to PIO data transport.
I have "repaired" 3 systems with that error.
Go into SYSTEM hardware section, and delete the disk interface.
Sounds scary, but it seems oke.
On reboot, repair of that follows, and with luck your dma
access will be restored, and your speed back.
What happened, is that windows had a disk error, and went to
PIO mode because of that. Very safe, but slow.

 

[goldtech]

Disk might have switched from dma to PIO data transport.
I have "repaired" 3 systems with that error.
Go into SYSTEM hardware section, and delete the disk interface.
Sounds scary, but it seems oke.
On reboot, repair of that follows, and with luck your dma
access will be restored, and your speed back.
What happened, is that windows had a disk error, and went to
PIO mode because of that. Very safe, but slow.- Hide quoted text -

- Show quoted text -

Bad hard disk according to a test I can run from laptop's BIOS. You
are correct - it's the disk. I get new one - still under warranty and
hope that solves it.
Tried what you said but seems it's bad HD. Laptop disks are not as
robust as desktops imo...

Thanks

 

[Loren Pechtel]

Hi,

I realize my laptop is not homebuilt but I need expertise...

I am completely clueless here. My laptop has slowed to a crawl for no
apparent reason. It's as if the CPU itself has slowed, or acting like
it is starved for physical memory. The slowness is not on the OS
software level. Linux and XP are both slow. Booting is slow, bios
flashing is slow everything no matter what crawls. Video is slow.

I have a fast machine with 3gig memory.

What could cause everything to slow?
My HD checks OK on tests I've tried...I thought maybe the HD is on
it's way out. But there's not noise or excessive cranking.

What could it be?

Tried a reformat and reinstall. Reinstall was slow - took hours were
is usually takes about 1/2 hr...

Lee g.

I don't have any answers but I've seen this before with a PC. One day
it got about 10x as slow as it used to be. It was old and pretty
barren anyway, we didn't spend much time trying to solve it.

I had a suspicion something had happened to the oscillator that drives
it but nobody around had the electronics knowledge to test this.

 

[Paul]

I don't have any answers but I've seen this before with a PC. One day
it got about 10x as slow as it used to be. It was old and pretty
barren anyway, we didn't spend much time trying to solve it.

I had a suspicion something had happened to the oscillator that drives
it but nobody around had the electronics knowledge to test this.

An "interrupt storm" can slow down a PC. It doesn't have to be
an off-frequency oscillator.

http://en.wikipedia.org/wiki/Interrupt_storm

Also, the BIOS ability to deliver an SMI (system management interrupt),
can hobble a PC, and the SMM subsystem isn't even visible to Windows
(you can only tell something is going on, by loss of "time"). A problem
with SMM would be hard to debug, because the root cause might be the
motherboard itself.

http://en.wikipedia.org/wiki/System_Management_Mode

There are also things like "Throttlegate" (a Dell problem).

http://www.engadget.com/2010/07/25/dell-finally-makes-right-offers-up-rated-power-adapters-to-clos/

Someone did a lot of analysis, to get Dell's attention. This
document has been on a couple different sites, and probably
gets moved because of the bandwidth it consumes when people
download it. I don't know if it's still here or not.

http://www.sigmirror.com/files/44490_iweoz/throttlegate.pdf

Some of the other causes might be easier to debug, because
certain things may trigger them. For example, a computer
may be held hostage by the hard drive, if say, there is a
bad sector on the disk, you ask for it, and it takes ten
seconds for the drive to read the sector. It might not
take that much disk activity (not that many operations),
to result in long stalls.

I've seen a PC, pretty well frozen, trying to read a bad DVD.
Those kinds of things, are easier to figure out, because
something you do, tends to kick off the behavior.

Sometimes it's software. I found my CD burning software,
would freeze up, if there was software present which would
mount an ISO as a "virtual CD". Apparently the burner software
was trying to "talk" to the other piece of software. And the
results weren't good. Disabling the "virtual CD" (as I wasn't
using it and had forgot about it), fixed it.

Paul

 

[Loren Pechtel]

An "interrupt storm" can slow down a PC. It doesn't have to be
an off-frequency oscillator.

http://en.wikipedia.org/wiki/Interrupt_storm

Also, the BIOS ability to deliver an SMI (system management interrupt),
can hobble a PC, and the SMM subsystem isn't even visible to Windows
(you can only tell something is going on, by loss of "time"). A problem
with SMM would be hard to debug, because the root cause might be the
motherboard itself.

http://en.wikipedia.org/wiki/System_Management_Mode

There are also things like "Throttlegate" (a Dell problem).

http://www.engadget.com/2010/07/25/dell-finally-makes-right-offers-up-rated-power-adapters-to-clos/

Someone did a lot of analysis, to get Dell's attention. This
document has been on a couple different sites, and probably
gets moved because of the bandwidth it consumes when people
download it. I don't know if it's still here or not.

http://www.sigmirror.com/files/44490_iweoz/throttlegate.pdf

Some of the other causes might be easier to debug, because
certain things may trigger them. For example, a computer
may be held hostage by the hard drive, if say, there is a
bad sector on the disk, you ask for it, and it takes ten
seconds for the drive to read the sector. It might not
take that much disk activity (not that many operations),
to result in long stalls.

I've seen a PC, pretty well frozen, trying to read a bad DVD.
Those kinds of things, are easier to figure out, because
something you do, tends to kick off the behavior.

Sometimes it's software. I found my CD burning software,
would freeze up, if there was software present which would
mount an ISO as a "virtual CD". Apparently the burner software
was trying to "talk" to the other piece of software. And the
results weren't good. Disabling the "virtual CD" (as I wasn't
using it and had forgot about it), fixed it.

Most of these couldn't apply in the situation in question: This was a
dos box and the problem was evident even when doing things that didn't
do any disk activity. CPU time was going somewhere. I do agree that
errant interrupts could have been the cause--as I said, we didn't
investigate it much. We ruled out obvious problems and then chucked
it.