Beginners Guides: Diagnosing Bad Memory

Zardon · Apr 2, 2004, 07:27 AM

Does your Windows-based PC crash for no apparent reason? Well OK, mine does too, but does yours crash often? At random times? With Nasty blue Screens of Death? If the answer is "yes", you may very well have a memory problem. Faulty memory, or RAM, is often the cause of the dreaded 'flaky PC' syndrome, those hard-to-replicate errors that get you nasty looks from the store technician because "…nothing seems to be wrong with it. Sir."

pcstats

**dj_stick** · Apr 2, 2004, 10:40 AM

hmm this may just solve my problem…

Matth · Apr 2, 2004, 05:23 PM

You also need a LOT of patience to track down memory which is merely "unreliable".

The Bios RAM test (with quick boot disabled) will normally find any unconditionally bad, hard-fault ridden memory - and the system would be pretty well inoperable.

A single "all test" pass with any of the test software, should find any more complex, but repeatable errors.

I'm not convinced that most of the test programs have an optimum strategy for finding UNRELIABLE memory... I just wish I was good enough to add my own tests...

1. Use optimized writes - 8 byte MMX registers, or SIMD streaming.
2. Use a simple strategy (eg. seeded/reseeded random number generator)
3. To test working/holding, divide the memory into two groups, and alternate several rapid cycles on one, with a longer duration store and verify on the other

Apr 2, 2004, 07:27 AM	#1
Zardon DriverHeaven Founder Join Date: May 2002 Posts: 32,480 Rep Power: 179	Beginners Guides: Diagnosing Bad Memory Does your Windows-based PC crash for no apparent reason? Well OK, mine does too, but does yours crash often? At random times? With Nasty blue Screens of Death? If the answer is "yes", you may very well have a memory problem. Faulty memory, or RAM, is often the cause of the dreaded 'flaky PC' syndrome, those hard-to-replicate errors that get you nasty looks from the store technician because "…nothing seems to be wrong with it. Sir." pcstats

Apr 2, 2004, 05:23 PM	#3
Matth Flash Banner Hater Join Date: Jun 2002 Location: UK Posts: 3,426 Rep Power: 93 System Specs	You also need a LOT of patience to track down memory which is merely "unreliable". The Bios RAM test (with quick boot disabled) will normally find any unconditionally bad, hard-fault ridden memory - and the system would be pretty well inoperable. A single "all test" pass with any of the test software, should find any more complex, but repeatable errors. I'm not convinced that most of the test programs have an optimum strategy for finding UNRELIABLE memory... I just wish I was good enough to add my own tests... 1. Use optimized writes - 8 byte MMX registers, or SIMD streaming. 2. Use a simple strategy (eg. seeded/reseeded random number generator) 3. To test working/holding, divide the memory into two groups, and alternate several rapid cycles on one, with a longer duration store and verify on the other