What happens if part of your RAM stick is defective?

[Richard]

I've bought some second-hand RAM (2 x 128Mb PC100). I'm now using it in
conjunction with a 64Mb PC100 stick I already had. System Information ought
to show 320Mb but only shows 288Mb, thats 32Mb too low. I guess one of those
128Mb RAM sticks is defective. True? I have done a memory test and that
shows no problems, but of course, it just tests the 288Mb.

 

[Ken Blake, MVP]

I've bought some second-hand RAM (2 x 128Mb PC100). I'm now using it
in conjunction with a 64Mb PC100 stick I already had. System
Information ought to show 320Mb but only shows 288Mb, thats 32Mb too
low. I guess one of those 128Mb RAM sticks is defective. True?

No, not true. A defective RAM stick just wouldn't work. It wouldn't decrease
the amount of memory it had.

Almost certainly you have no separate video card, but your motherboard
provides video support and is using 32MB of your main memory for that. That
leaves only 288MB for Windows.

This was always true, not just now after you added memory. You just never
noticed it before.

 

[Jacques Trépanier]

Try running MEMTEST86. it will tell you how much RAM is installes plus more
info.

Go to http://www.memtest86.com/

Good luck,

 

[Leythos]

A defective RAM stick just wouldn't work.

Technically, RAM can be bad and still work until you reach that point in
memory where it's faulty. I've seen instances where applications ran
fine until they reached the memory point where there was a problem -
although very rare, it does happen.

 

[Richard]

The missing ram could be dedicated to a motherboard video chip.

I wonder if the 64Mb RAM stick is different memory from the two new 128Mb
RAM sticks. Everything is PC100. When I put in the two 128Mb sticks I do
see 256Mb. I'm sure the 64Mb is okay, I've used that for quite some time,
but just 32Mb just gets added when that is put in the DIMM socket alongside
the new 128Mb sticks I just purchased.

I've got:

Bank 0 128Mb
Bank 1 128Mb
Bank 2 64Mb

Sadly, it just adds up to 288Mb om my PC.

 

[MAP]

I've bought some second-hand RAM (2 x 128Mb PC100). I'm now using it
in conjunction with a 64Mb PC100 stick I already had. System
Information ought to show 320Mb but only shows 288Mb, thats 32Mb too
low. I guess one of those 128Mb RAM sticks is defective. True? I have
done a memory test and that shows no problems, but of course, it just
tests the 288Mb.

The missing ram could be dedicated to a motherboard video chip.

 

[Ken Blake, MVP]

Technically, RAM can be bad and still work until you reach that point
in memory where it's faulty. I've seen instances where applications
ran fine until they reached the memory point where there was a
problem - although very rare, it does happen.

Yes, but it still wouldn't report a size lower than what it actually was.
The size report would still be accurate; it just wouldn't work, as I said.
Where or when it failed is a different issue, and wasn't the point I was
trying to make