On Thu, 11 Mar 2004 17:38:09 -0500, "Martin Racette"
Good one!
You've pretty much reached the end of this tshooting wizard, so I'll
step back from the SCSI-to-IDE focus and take a biiger view
The following problems can cause massive slowdown:
1) Disabled L1 and/or L2 cache in CMOS
Expect a smooth but profound slowdown, while the system runs
reasonably stably. Slowdown kicks in from power up onwards.
2) Failing HD and sector retries
Accessing HD should take a fraction of a second, but can get bogged
down for seconds at a time if the sector is physically unreadable, as:
- each calling layer may retry several times; nesting/multiplication
- the HD's firmware tries to relocate the sector contents on the fly
- if NTFS, OS also tries to relocate the sector contents on the fly
Expect a patchy slowdown that isn't related to uptime, and can be
associated with instabilities (depending on what files are affected -
often it will be those most often used, so expect registry crises)
While slow, the HD LED will be on, and the HD will either be silent or
make cyclical noises (cylinder seeks). The mouse pointer will
typically stick and keystrokes be ignored during the pauses.
3) Processor retreating into thermal protection
If processor overheats, it may protect itself by stopping for a while
(e.g. the old Socket 7 generation) or by slowing down smoothly but
failry profoundly (newer generations). This will start a while after
cold boot, and may be associated with instability.
4) Interrupt flooding
A defective hardware device may flood the system with interrupt
requests, crowding out processing time for everything else. Expect
stability issues if this is the cause.
5) Malware
Sometimes the performace impact of malware will be so severe as to
fall into the category. The effect may be worse when online.
The following problems can cause significant slowdown:
a) Malware and other underfootware
Traditional malware (worms, viruses etc.), commercial malware (usually
worse when online) and other underfootware such as multiple resident
antiviruses, indexing services and so on.
Suppress these in MSConfig and test, and compare with Safe Mode. Safe
Mode is usually slower because less efficient drivers are used, so if
you get the reverse mileage, chase this category of problem.
b) Less efficient HD operating modes
If you use a 40-pin IDE data cable, you restrict your HD to sub-UIDE66
modes. Other issues - controller drivers, CMOS settings etc. - may
force PIO or lower UIDE modes, and hurt too. Expect the system to be
smoothly slower from the moment you start up, and stable.
c) Cluttered directories
More likely to be a problem in FATxx than NTFS, because NTFS uses an
indexed structure to avoid linear look-up. Anything that dumps masses
of entries in an oft-used directory will have this effect, even if the
files themselves are small; it's the long and fragmented directory
itself that causese the slowdown, which also opens the critical window
for updates and thus increases the risk of corruption. Cases:
- TIF (a given, when MS's stupid defaults are left in)
- Temp
- the Windows base dir, if MDM.EXE running (kill via IE's Options)
- the root dir (certain malware in particular)
d) System Restore
Anything that "strobes" a monitored file will have an exaggerated
effect as SR continually makes backup copies of the altered file.
This is typical when a program uses a monitored file type as a log
file, as log files are typically opened and closed repeatedly so that
changes are kept even if the system suddenly dies.
Commercial av have been implicated in this on WinME.
e) Fragmentation issues
After a volume conversion, your files may be left fragmented
(especially if cluster size increased) or in the "wrong place". The
first defrag you do after such cases will take forever, but will
likely help overcome the problem immediately.
f) Networking issues
A bad LAN cable can have similar impact to a failing HD, looking much
the same except less "patchy" and the HD LED won't always be on.
Other LAN issues will have a milder effect. The problem may be off
your PC, i.e. some other PC or device constantly accessing yours.
g) Memory (mis)management
If left to its own devices, Windows will generally not screw up here.
It's when "memory optimizers" are added or custom settings are
applied, such as forced limits on swap or cache, that things slow down
That's all that comes to mind right now - I do have the feeling I've
left out stuff, but must move on, alas!
"Why do I keep open buckets of petrol next to all the
ashtrays in the lounge, when I don't even have a car?"
