R
Robbie Hatley
First of all... wow, no new threads in this group in 6 days?!
That's rather unusual.
Now, to the main topic of this post: As some of you guys and gals
may recall, I've been posting in here every couple weeks for the last
few months about my "COMPUTER KEEPS CRASHING" issue. To recap, my
Win2K-SP4 system has been crashing roughly once a day for months.
The crash always involves the following symptoms happening
simultaneously:
- usb mouse goes offline (mouse pointer stops responding to it)
- serial mouse does NOT go offline (mouse pointer responds)
- all networks (ethernet, usb, 1384, Internet) go offline
- sound starts cutting in and out about 3 times per second
I've tried many things to fix it, all to no avail. At times
I thought I'd fixed the problem, only to have it come back
a few days later. As I put it in one post:
But de cat came back, he couldn't stay no long-er,
Yes de cat came back de very next day,
De cat came back -- thought she were a goner,
But de cat came back for it wouldn't stay away.
Well, guess what? I finally killed the damn cat, and the
problem wasn't even REMOTELY close to any of my previous
guesses, or to any of the advice others gave me. (No
criticism of folks here implied; the actual cause was so
bizarre that I don't blame anyone for not guessing it.)
The cause? Incorrect AGP aperture size.
I'd never have guessed that, but for an incident that
occurred about 10 days ago. I was working along, and
suddenly my screen froze for three seconds (stopped
responding to mouse or keyboard), went black for two
seconds, then returned to normal. THAT LOOKED VERY
FAMILIAR. I'd seen that before! It was a video-mode
reset. My old CRT monitor used to go "CLINK", go black
for 2 seconds, go "CLANK", then return to normal. My
new LCD monitor uses solid-state electronics instead of
noisy mechanical relays, so it doesn't CLINK/CLANK, but
it still goes black for 2 seconds during mode reset.
I seemed to recall having that problem before, so I looked
in my Computer Journal (a text file in which I record
computer maintainance issues from time to time). Sure
enough, from 2005, I found these entries:
~~~~~~~~~~~~ BEGIN COMPUTER JOURNAL EXCERPT ~~~~~~~~~~~~~~~~~~~
Sun. Jun. 19, 2005:
I've been having some annoying problems lately:
I've been experiencing frequent video-mode resets, especially
while operating scrollbars on windows screens; the monitor goes
"CLINK", goes black for 2 seconds, goes "CLANK", then returns to
normal, except for some scrambled content in windows, and some
bad pixels in window frames, both of which usually (but not
always) will correct themselves on minimize, restore.
Also, sometimes my system just freezes up in the middle of work,
video image frozen, no response from keyboard (CAP-LOCK and
NUM-LOCK buttons won't toggle LEDs), no response from mouse
(pointer is frozen). I have to press the front-panel "Reset"
button on my machine to un-freeze it.
Tue. Jun. 24, 2005, 4:00AM:
I replaced my video card with a BFG nVidia GeForce MX 4000 128MB
AGP8X. The instructions were very adamant about several issues:
1. The old drivers MUST be uninstalled before installing new
drivers.
2. The BIOS "AGP Aperature" setting MUST match the number of MB
of RAM on the video card.
3. System BIOS and video BIOS "shadow" or "caching" MUST be
turned OFF.
Sat Aug 27, 2005:
After about 90 days of heavy use, the problems listed above are
completely gone. I think now that these problems were entirely
due to a bad video card.
~~~~~~~~~~~~ END COMPUTER JOURNAL EXCERPT ~~~~~~~~~~~~~~~~~~~
So it turned out, I'd had both the crash problem and the video mode
reset problem before. And I'd fixed them, and they'd stayed fixed
for some months.
So, what did I do to fix them? Four things:
1. Replaced video card.
2. Set "System-BIOS Caching" to "Off" in BIOS settings.
3. Set "Video RAM Caching" to "Off" in BIOS settings.
4. Set "AGP Aperture Size" to match video RAM size in BIOS settings.
So what changed, that would cause the malfunctions to resume?
1. Video card? Still same card, and still seems to be working ok.
2. System BIOS Caching? Still "Off".
3. Video RAM Caching? Still "Off".
4. AGP Aperture Size = Video RAM size?
Video RAM Size = 128MB.
AGP Aperture Size = 256MB.
OOPS.
So about 10 days ago (around March 9, 2010) I changed my AGP Aperture
Size, which had somehow got set to 256MB, back to 128MB where it
belongs. I haven't had any crashes or mode resets since.
Odd that AGP Aperture Size is such a critical setting! I actually
examined that setting about a month ago while trying to fix my crash
problem. I looked it up on the web, and most sites give this advice:
"AGP Aperture size can be set to just about anything you want;
it doesn't matter; it has little effect on performance; most
people should just set it to 256MB and leave it there."
The only problem with that advice is, it's 100% pure unadulterated
BULLSHIT! The correct advice would be:
"Always set AGP Aperture Size to the value demanded by your video
card manufacturer. Failure to comply may cause memory corruption
and system crashes do to mis-match between how much memory the
video driver thinks is allocated for AGP usage, and how much memory
BIOS has *ACTUALLY* allocated. If Aperture size is set too high --
say, 256MB when it should be 128MB -- your video driver will tell
windows that the upper 128MB of AGP Aperture memory is 'unused and
available for system use'. Windows will then attempt to use memory
which is actually in-use by BIOS and Hardware. This will cause
other drivers -- mouse, networks, sound -- to be overwritten in
RAM, causing the system to crash. Conversely, if AGP Aperture Size
is set too low, your video driver will write video data to usused
memory which is *NOT* linked to your video card, resulting in
corruption of video images."
So I think now that my crashing and video problems in 2005 were *NOT*
due to a bad video card, but rather to AGP Aperture Size being set
incorrectly.
Similarly, my crashing problems over the last few months were not
due to viruses, software, hardware, BIOS, power glitches, cosmic
rays, driver conflicts, services, daemons, demons, aliens, karma,
etc, etc, etc... but rather to AGP Aperture Size being set
incorrectly.
Amazing (and infuriating) how one obscure, poorly-understood
(and completely undocumented) BIOS setting can reck so much havoc.
Live and Learn.
De cat didn't come back, no, he went away for good,
no more to be seen in dis neighborhood!
Yep, de cat didn't come back, fo he went to meet his maker;
that old man Hatley, he's a real cat breaker!
--
Cheers,
Robbie Hatley
lonewolf at well dot com
www dot well dot com slant tilde lonewolf slant
That's rather unusual.
Now, to the main topic of this post: As some of you guys and gals
may recall, I've been posting in here every couple weeks for the last
few months about my "COMPUTER KEEPS CRASHING" issue. To recap, my
Win2K-SP4 system has been crashing roughly once a day for months.
The crash always involves the following symptoms happening
simultaneously:
- usb mouse goes offline (mouse pointer stops responding to it)
- serial mouse does NOT go offline (mouse pointer responds)
- all networks (ethernet, usb, 1384, Internet) go offline
- sound starts cutting in and out about 3 times per second
I've tried many things to fix it, all to no avail. At times
I thought I'd fixed the problem, only to have it come back
a few days later. As I put it in one post:
But de cat came back, he couldn't stay no long-er,
Yes de cat came back de very next day,
De cat came back -- thought she were a goner,
But de cat came back for it wouldn't stay away.
Well, guess what? I finally killed the damn cat, and the
problem wasn't even REMOTELY close to any of my previous
guesses, or to any of the advice others gave me. (No
criticism of folks here implied; the actual cause was so
bizarre that I don't blame anyone for not guessing it.)
The cause? Incorrect AGP aperture size.
I'd never have guessed that, but for an incident that
occurred about 10 days ago. I was working along, and
suddenly my screen froze for three seconds (stopped
responding to mouse or keyboard), went black for two
seconds, then returned to normal. THAT LOOKED VERY
FAMILIAR. I'd seen that before! It was a video-mode
reset. My old CRT monitor used to go "CLINK", go black
for 2 seconds, go "CLANK", then return to normal. My
new LCD monitor uses solid-state electronics instead of
noisy mechanical relays, so it doesn't CLINK/CLANK, but
it still goes black for 2 seconds during mode reset.
I seemed to recall having that problem before, so I looked
in my Computer Journal (a text file in which I record
computer maintainance issues from time to time). Sure
enough, from 2005, I found these entries:
~~~~~~~~~~~~ BEGIN COMPUTER JOURNAL EXCERPT ~~~~~~~~~~~~~~~~~~~
Sun. Jun. 19, 2005:
I've been having some annoying problems lately:
I've been experiencing frequent video-mode resets, especially
while operating scrollbars on windows screens; the monitor goes
"CLINK", goes black for 2 seconds, goes "CLANK", then returns to
normal, except for some scrambled content in windows, and some
bad pixels in window frames, both of which usually (but not
always) will correct themselves on minimize, restore.
Also, sometimes my system just freezes up in the middle of work,
video image frozen, no response from keyboard (CAP-LOCK and
NUM-LOCK buttons won't toggle LEDs), no response from mouse
(pointer is frozen). I have to press the front-panel "Reset"
button on my machine to un-freeze it.
Tue. Jun. 24, 2005, 4:00AM:
I replaced my video card with a BFG nVidia GeForce MX 4000 128MB
AGP8X. The instructions were very adamant about several issues:
1. The old drivers MUST be uninstalled before installing new
drivers.
2. The BIOS "AGP Aperature" setting MUST match the number of MB
of RAM on the video card.
3. System BIOS and video BIOS "shadow" or "caching" MUST be
turned OFF.
Sat Aug 27, 2005:
After about 90 days of heavy use, the problems listed above are
completely gone. I think now that these problems were entirely
due to a bad video card.
~~~~~~~~~~~~ END COMPUTER JOURNAL EXCERPT ~~~~~~~~~~~~~~~~~~~
So it turned out, I'd had both the crash problem and the video mode
reset problem before. And I'd fixed them, and they'd stayed fixed
for some months.
So, what did I do to fix them? Four things:
1. Replaced video card.
2. Set "System-BIOS Caching" to "Off" in BIOS settings.
3. Set "Video RAM Caching" to "Off" in BIOS settings.
4. Set "AGP Aperture Size" to match video RAM size in BIOS settings.
So what changed, that would cause the malfunctions to resume?
1. Video card? Still same card, and still seems to be working ok.
2. System BIOS Caching? Still "Off".
3. Video RAM Caching? Still "Off".
4. AGP Aperture Size = Video RAM size?
Video RAM Size = 128MB.
AGP Aperture Size = 256MB.
OOPS.
So about 10 days ago (around March 9, 2010) I changed my AGP Aperture
Size, which had somehow got set to 256MB, back to 128MB where it
belongs. I haven't had any crashes or mode resets since.
Odd that AGP Aperture Size is such a critical setting! I actually
examined that setting about a month ago while trying to fix my crash
problem. I looked it up on the web, and most sites give this advice:
"AGP Aperture size can be set to just about anything you want;
it doesn't matter; it has little effect on performance; most
people should just set it to 256MB and leave it there."
The only problem with that advice is, it's 100% pure unadulterated
BULLSHIT! The correct advice would be:
"Always set AGP Aperture Size to the value demanded by your video
card manufacturer. Failure to comply may cause memory corruption
and system crashes do to mis-match between how much memory the
video driver thinks is allocated for AGP usage, and how much memory
BIOS has *ACTUALLY* allocated. If Aperture size is set too high --
say, 256MB when it should be 128MB -- your video driver will tell
windows that the upper 128MB of AGP Aperture memory is 'unused and
available for system use'. Windows will then attempt to use memory
which is actually in-use by BIOS and Hardware. This will cause
other drivers -- mouse, networks, sound -- to be overwritten in
RAM, causing the system to crash. Conversely, if AGP Aperture Size
is set too low, your video driver will write video data to usused
memory which is *NOT* linked to your video card, resulting in
corruption of video images."
So I think now that my crashing and video problems in 2005 were *NOT*
due to a bad video card, but rather to AGP Aperture Size being set
incorrectly.
Similarly, my crashing problems over the last few months were not
due to viruses, software, hardware, BIOS, power glitches, cosmic
rays, driver conflicts, services, daemons, demons, aliens, karma,
etc, etc, etc... but rather to AGP Aperture Size being set
incorrectly.
Amazing (and infuriating) how one obscure, poorly-understood
(and completely undocumented) BIOS setting can reck so much havoc.
Live and Learn.
De cat didn't come back, no, he went away for good,
no more to be seen in dis neighborhood!
Yep, de cat didn't come back, fo he went to meet his maker;
that old man Hatley, he's a real cat breaker!
--
Cheers,
Robbie Hatley
lonewolf at well dot com
www dot well dot com slant tilde lonewolf slant
