Running your memory the right way/ running 4 DIMM slots on P55 boards

Question

Dear Forumers,
Lately there are a lot of questions, about motherboards from the P55 range not starting on first boot.
This could be due to wrongly arranged memory DIMM's in your slots.
Some people out there, like me, were convinced that you could choose either dualchannel.
Well, its not the case.
Like I was pointed out earlier, you must use a certain slot, otherwise the memory will not be detected properly.
According to Intel specs, DIMM0, must always be populated.
This means that to run dualchannel with only 2 DIMM's, that you must check your manual and look carefully which slot is for DIMM0.
According to the manual, it will be slot DIMM1 on your board, but watch out, this is not the slot closest to cpu, on current MSI P55 boards, (CD-53, GD-41, GD-45, GD-55, GD-65, GD-80 and the Big Bang Trinergy), its the second slot from cpu.
Picture of P55 mainboard:
From a manual from a MSI P55 board:
So for dualchannel with 2 sticks, you must populate the black slots, DIMM1 and DIMM3 and for single channel with one stick DIMM1 most be used.
Please bear in mind that DIMM0 in Intel spec.sheets means DIMM1 on your board.
The link to technical sheet from intel about : i7 8xx cpu's
http://download.intel.com/design/processor/datashts/322164.pdf
A short quote with the relevant data:
Quote
Rules for Populating Memory Slots
In all modes, the frequency of system memory is the lowest frequency of all memory
modules placed in the system, as determined through the SPD registers on the
memory modules. The system memory controller supports one or two DIMM
connectors per channel for unbuffered DIMMs. For dual-channel modes, both channels
must have at least one DIMM connector populated and for single-channel mode only a
single-channel may have one or more DIMM connectors populated.
Note: DIMM0 must always be populated within any memory configuration. DIMM0 is the
furthest DIMM within a channel and is identified by the CS#[1:0], ODT[1:0], and
CKE[1:0] signals.
For more info, please read datasheet
Also, let me remind you that this goes for ALL P55 boards out there, its not just an MSI thing.
This has to do with the fact that the memorycontroller now sits on die on the Lynnfield cpu's.
Im hoping to end the debate, like I had (and I was wrong), about the fact that you should be able to use any channel, like you could on the S775 boards, you just cant anymore.
Update 26 december 2009:
Running all 4 DIMM slots with memorysticks
It seems that a lot of people are having problems running with all memoryslots occupied, e.g. not booting, BSOD and other crazy stuff.
If you have such problems try the following first, before running back to the store to swap stuff out.
- Raise Vdimm to 1.65V, its still a save voltage for the board and this way the memory gets a little more power and in 99% of the cases, this will solve the issue.
- Try booting/installing with one stick first in DIMM1 on the board  (see above).
- If it boots/installs, let it go all the way till windows is done.
- Turn off pc and add a second DIMM in DIMM slot 3, restart and let i boot all the way again in windows till its done.
- Do the same again for DIMM2 and last DIMM4.
We know its a bit of a hassle, but it worked for a lot of people, so be sure to try this before anything else.
And again, its not just an MSI thing, there are more manufacturers out there with the same issues, this also has to do with the fact the memorycontroller now sits on die with cpu.
I'll edit if new boards come out.
--I made your images clickable
  Click the modify button to see how I did it.
--Mike

Answer 1

Upgrading Mother Board (P55-GD65 with i3 processor) BIOS [/b] from 1.3 to 1.6 corrected my Computer re-starting soon after the Boot sequence began.  Putting the four 2GB RAM in one at a time in the suggested order in sequence with the socket numbers fixed the problem earlier, but only for the next, one boot.  The problem then returned as long as all 4 DRAM were installed.  Raising the DRAM voltage did not improve things. 
I used the Forum's program for flashing the new version of Bios using USB Flash Memory for boot into DOS.
Thank you, DaLoona, for your post notifying me this had to do with the motherboard and was probably not a failure, but a "normal" occurance in certain conditions.  I was no longer inclined to return the board and perhaps end up with the same error in the replacement, and no longer worried about the rebooting doing damage. 
In Bios Setup I had already reduced an entry to do with number of overclocking tries from 3 to 1 (the minimum choice) which reduced the number of re-boots to 1.