Jumbo said:
Son is having memory problems.
With 4 x 2GB sticks installed the BIOS sees 8GB but Win7 blue screens.
With 3 x 2GB + 1 x 1GB Win7 runs no problems.
When Googling there appears to be 100's Win7-64bit users with similar
problems and numerous suggestions to fix.
Anyone have a similar problem and did they fix it and how.
A BIOS address map problem ?
Why would Windows 7 choose to freak at 8GB ?
A more natural place for an OS to have problems, is at the 4GB point.
The vintage of the motherboard, the chipset used, may be part of the
problem. While modern chipsets have much larger address spaces, than
the installed RAM, there were some in the past, where 8GB installed
memory needs to be "shoe horned". (I.e. Chipset max address space is
8GB, OS reports "7GB free", so you don't actually get to use all the
RAM.)
*******
If you post the make and model number of computer, or the make
and model number of motherboard used (on a home build), it allows
the comments to be a bit more focused.
*******
If you thought the problems were RAM related, you could use memtest86+.
(Scroll half way down the page, to find the download links)
http://www.memtest.org/
Test cases:
1) Start with single sticks of RAM first. This is to allow easy isolation
of exactly the defective stick. If you're in a hurry, just complete
one pass of Test 5. If you spot a stuck-at error, where the same address
is bad each time the test is run, then you have a stick of bad RAM.
Memtest86+ isn't really the best tool, for dynamic faults, and passing
memtest86+ is not an "acceptance test". A tool like Prime95 is better
for that, and on a "large RAM" machine, you have to test with more care
(design your test case a bit better, for it to be valid).
2) If you suspected a "bad RAM slot" problem, you'd walk the same single
stick, through all four RAM slots, then compare the test results.
This is an optional test, unless you have evidence that a single slot
is implicated for some reason.
3) Once each stick has been tested singly, and is completely error free,
you test a matched pair. You put one stick on each memory channel.
This is a "dual channel" test. Some chipsets, become unstable from
the extra noise from the second channel operating. That's why, this
is a separate test case, to see if the system is minimally
"dual channel stable". Now, we're not talking about the RAM
being at fault, but more about the motherboard or memory bus being
the problem.
4) Your next test, would be four matched sticks. Some Nvidia chipsets,
have had a good deal of problems, and you'll see different behavior
depending on RAM configuration (blows up with four sticks). If this
happens, you may need to trace down a forum that has characterized
the problem. In some cases, you have to drop the memory clock, a lot.
It really isn't necessary to test multiple passes with memtest86+. Since
it isn't a good enough test to be considered an acceptance test, multiple
passes are pointless. Try one pass minimum, and if you're in a real rush
(i.e. had too much caffeine), just do Test 5 the one time, then move on.
That will speed up the test process, at the expense of thoroughness.
With the latest versions of memtest86+, the tool will test larger quantities
of memory. A nice bonus from this, is if you watch how the test progresses,
you'll see memtest86+ "testing in chunks". The chunks, hint at how the
address space is arranged. Like, if the chipset is remapping memory addresses,
you may see memory below 4GB tested first (a 3GB region, as the upper 1GB
may be reserved for PCI or PCI Express cards). Then, a 1GB segment, which
is remapped above 4GB. Then, some number of addition tests, for memory
which is higher in address space than that. So if you watch the range of
addresses being tested, it tells you something about whether remapping
is being used, and how it is set up.
I'm not aware of any tools that decode the hardware setup in a machine,
in a human friendly way. At least, with regard to remapping, max
address boundaries, or the like.
HTH,
Paul
So no wastage.