determining whether or not ram has gone bad

How does one go about determining whether or not RAM has gone bad? It
seems to me that any symptoms attributable to bad RAM could also be
attributed to a problem that a simple reformat would fix.

 

Memtest86+ (memtest.org) tests memory, and has nothing to do with
the hard drive. It can be used to test the computer memory.

Similarly, a program like Prime95 from mersenne.org, has a torture
test option, and it tests the operation of the CPU, Northbridge, and
memory DIMMs. It doesn't touch the hard drive either. So this program
can help determine whether there is a problem, with something other than
the hard drive. A nice version, suitable for testing while in Windows,
for a single or multi core processor, is here. If you get an error,
you've got a problem. If that happens, come back, for more help.

http://www.mersenne.org/gimps/p95v255a.zip

A "reformat" is for fixing a hard drive. A different animal altogether.
RAM and hard drives are two different kinds of hardware.

Paul

 

If you're computer periodically freezes, it could be because you've
gotten some badly written spyware installed that causes it to freeze
or (it seems to me) could be because you have some bad RAM. Based on
that, alone, could you tell me, for sure, where the problem lay? If
not, then why are you assuming that I don't know the difference
between RAM and hard drives when, by that same criteria, you wouldn't,
either?

Regardless, I do appreciate the post and the links - thanks!

 

Well, at least now I have some clue what you were thinking about.

Paul

 

The confusion comes from your question about reformatting RAM. You can not
reformat the RAM.

You can have a pile of processes loading into RAM that you do not need, and
the result is significant reduction of performance. A program such as
HiJacker.exe will tell you what is loading, and where it came from. You can
tell an app that loads at boot time to stop loading, and this will free up
resources. There are other programs that do this as well, I just mentioned
one to get you started.

As for apps that load at boot time, you can have Adobe Acrobat -- for
example -- get loaded every time you start your machine, but maybe you only
open PDF files once in a great while. If this is the case, set Adobe Acrobat
to NOT load, then start it manually when you feel like viewing PDF files.
There are other files like Adobe that will load with every boot cycle, and
these apps will rob you of memory that you might want to have available for
other stuff.

You can not reformat RAM, but you can empty it.

 

When I said reformat in my orig. message I was referring to the hard
drive. If rebooting (ie. clearing the RAM) doesn't fix the problem,
then the problem is likely due to something a bit more persistent.
Like bad RAM or a bad combination of software (ie. something that "a
simple reformat would fix"). The reason I said it that way is because
I couldn't, at the time I was making my post, think of a good way to
succinctly (ie. 2-4 words or something) describe the scenario I
described earlier, so I opted to circumlocute my way around it.

 

Okay, now I get it. That was not clear. Sorry for my confusion.



If rebooting (ie. clearing the RAM) doesn't fix the problem,

Well, you still need to look to see what is loading on boot. The Task
Manager will tell you what is running. Right Click onmthe Tool Bar at the
bottom of the Desktop, select Task Manager, then choose the Processes tab.
My brother dropped off HiJacker.exe, and it tells me what is loading and
where it came from. I can look at a process and determine if it is from an
app that I know about, or one that came to be via a virual enhancement.

If you have 512M of RAM, and load 500M of shit, then your RAM is not going
to perform very well. You might want all of that stuff to load, but then you
would need more RAM. My guess is that you really don't want all of the stuff
to load, and you probably want more RAM anyhow. (I don't recall how much RAM
you said you have, and I just tossed a number.)

"Bad" RAM should show up during boot-up if the BIOS screen is set on. "Bad"
RAM should show up in the Environment Variables too.

Right Click on My Computer, then select Properties. The available RAM should
be shown. You have to know how much RAM is installed to know if the
available RAM is the correct number.

 

It's impossible to give a definitive cause for
periodical freezes, but RAM is certainly one area to
investigate.
Download memtest86, make a boot floppy and run all the
tests.
This can take quite some time but will tell you for
certain the state of your RAM.
Having said this, a faulty RAM module can be found and
replaced and your PC may still freeze due to software
or other hardware issues.
At least you will eliminate one possible source.

 

I tried memtest86 once. Drove me mad. You cannot use the computer
while you are doing it - multitasking. It runs off a boot disk. And
recall starting itt, going to bed, getting up, and it was still going.

My way, is like all computer things. How do you check anything. You
have a replacement. RAM, Hard Drive. It takes ages to scandisk or
chkdsk a hard drive too. (win9x one used scandisk, and chkdsk was a
little dos program. With win xp, chkdsk is bigger, and there is no
scandisk)

If 2 sticks of RAM, remove one, and/or the other. See if any
difference.

Or just change the RAM in there with RAM on your shelf. You cannot
troubleshoot anything if you do not have "redundant" parts

You wanna fix your computer yourself you`re going to have to be a
techie. A good techie preferably. And that means redundant parts.For
me it is buying in parallel, researched technology that I know works,
is reliable.

 

And don't overlook the number one cause of most PC problems, the power
supply!...

 

Memtest86+ crashes with the following:

Unexpected Interrupt - Halting.

It shows the contents of a bunch of registers and shows the contents
of the stack.

I guess that means the RAM's bad? I would have expected Memtest86+ to
explicitly say "RAM is bad" or "RAM is good" - not to crash...

 

That suggests a mainboard problem. Could be CPU overheating. Or bad
caps.

 

Could be caused by a number of things, not necessarily
bad RAM.
Memtest may be trying to write to an area of reserved
memory due to an incorrectly reported map, fairly
common with some boards, try updating your BIOS.
What is the make and model of the motherboard?
Download a program called Prime95 to test your
processor.
http://www.mersenne.org/freesoft.htm
Use the CPU test first. If it can do it for several
hours, then CPU is OK.
After that you can test RAM also.
Are all your fans OK?
Have you blown everything out with a can of compressed
air?
Removed and reseated RAM, Video card etc?
If you have two sticks of RAM try removing alternate
ones and see if the problem remains.

 

I have seen more problems from CPU overheating than from any other single
cause.

Now, occasionally boards will just become unstable, intermittently. In
those cases,
there is but one cure.

There is, I am told, a process called "wear leveling" by which the
inevitable degradation
of solid state memory can be combated. All solid state memory can and will
suffer
some degradation because of radiation damage, and other issues. Wear
leveling
identifies those damaged areas and sidesteps them, IIUC.

 

AFAIAW "Wear Levelling" is not applicable to mainboard RAM. It is a
technique that is/can be used with "Flash Memory" in USB keys.

 

There is a nice article here, with some pointers to other docs.
Flash memory has a limit to the number of update cycles per sector,
and the general class of "Wear Leveling" algorithms are intended to
prevent one sector from being pounded to death. Due to the existence
of patents, the quality and type of method may vary from one
kind of flash product to another. It is quite possible that
some flash devices, have no wear leveling at all, which helps
explain the short usable lifetime. Even with wear leveling,
a concerted effort to use up the maximum cycles, can work to
ruin it.

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

System memory (dynamic random access memory) does not have the same
wear characteristic, and you can hammer the same location in RAM,
day after day, for years, without having to worry about it. Dynamic
RAM stores charge on a capacitor per cell, and the charge leaks off
in a short period of time. DRAM has a "refresh" feature, which
recharges the capacitors on a regular basis. That is how it remembers
stuff, by constantly restoring the state of each capacitor. But as
soon as the power is lost, the contents of the DRAM are gone.

(When you put a computer in "S3 sleep", the DRAM and refresh are
still running. Some motherboards have a green colored LED, that
shows power is still available to the sticks of DRAM. So the DRAM
continues to remember everything, because the refresh is still
running automatically. The processor is not needed to make the
refresh work, and the processor in that case is powered off.)

Paul