Hi,
The thing is, in the situations where less memory shows up because of
the way that it was installed or because of a "feature" that the board
has, you usually loos half the memory, not a quarter. For example, I
have systems where I can have the full amount installed, or if I or
someone else makes a change in the bios, I can half the amount but
have it emulate faster memory.
The coloring of slots is a good point which I forgot about.
Essentially, the reason why this is done is so that people can make
sure their memory is running in duel channel which is meant to combat
a bottlenec between the CPU and the memory controlor. The important
thing to remember here is that your eventual aim should be to have
your 2 channels fully populated so that both channels are runing in
duel channel.
Lets assume that you have 3x 2gb sticks and 4 slots on a board,
channel a having wite slots and channel b having blue slots. If we
install 2x sticks in channel a and 1x in channel b, the 4gb in channel
a will be running in duel channel mode because channel a is balanced -
E.G. both slots are populated with dims of the same capacity. The 2gb
in channel b will still function, but it will be running in single
channel mode as the channel is only half populated. If we increased
the total to 4x sticks, we would be able to fully populate both a and
b, so at last, both channels would be running in duel channel mode.
So, how do you make sure that you are installing your memory in such a
way that it all runs in duel channel as a blind person:
The easiest way is to populate all 4 slots. This is the approach that
I usually take; I tend to go a bit overkill on the memory side because
it's so cheap these days, so the problem of wanting to upgrade but
having to throw out 2 dims instead of one won't be happening for me
for a few years at least. Using this approach, it's simply not
possible for the channels to be unbalanced, because you've filled
every possible slot on your board.
If this is not possible - E.G. you have 4 slots but not 4 sticks, the
best approach depends on how many sticks you have. Assuming 2 sticks
and 4 slots, the best setup would be to fully populate one of the
channels and leave the other one empty, which begs the question of how
to tell which slots belong to which channel:
*Usually*, slot 1 and 3 will belong to a and slot 2 and 4 will belong
to b. Note that your motherboard manual will probably define which
slot is slot 1 or slot a, but that is of little importance; just
install a dim in the slot nearest you, skip a slot then install the
remaining dim and you will have most likely fully populated channel a
or b.
Getting back to the issue at hand after that rather long detour:
You have some very good suggestions baring in mind how hard it is to
troubleshoot hardware remotely. To completely rule out faulty
hardware, take the time to install dim 1 in slot 1, dim 2 in slot 1,
dim 3 in slot 1 etc. Make sure that you only have one dim in the
system so that if a dim is faulty, the board simply won't post- in
other words: every time windows lodes, you should see 8gb of ram. If
all of the tests complete successfully, we can assume all the dims
(I've used dims and sticks interchangeabley in this email) are working
and that in this example, slot 1 is functional. You next need to take
one of the dims and try it in slots 2, 3 and 4 and see what happens -
since we've verified that all the dims are functional, from a hardware
point of view, the only fault can now be a faulty slot. Assuming that
the board doesn't post with a dim installed in a given slot then
finally, you've diagnosed the fault.
However, if all of the above tests pass then it is most likely a
software issue and short of their being some sort of "feature" in your
bios that is doing this, I'm stumped. In this situation I'd probably
ask Gigabyte for help; it sounds like a new system, so the board
should still be under warranty which means you should still be able to
have free tech support.
I hope all the above helped someone.
Cheers,
Ben.
On 5/3/13, George Bell
David,
You say: "Processors, I've got an AMD fx8120 8 core processor in the system."
But the motherboard manufacturer says, "(Note 2) To support a DDR3 1866 MHz (and above) memory, you must install an AMD AM3+ CPU first."
Seems to be some debate regarding AMD FX series in an AM3+ board.
George.
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