I am using now 6 GB of RAM instead of 8, is this STILL okay???

Just a comment...

I have a system built around an ASUS P5Q3 board, which I believe is essentially the same as your P5Q board except for supporting faster DDR3 memory. My CPU is a Duo E8400, and I only have 2x2GB of DDR3 (PC3-10700) memory installed into DIMM slots A1+B1.

And my board has the same layout of A1/A2 and B1/B2 color-coded DIMM slots for memory.

I believe that to take advantage of dual-channel memory configurations, if you only have TWO cards (e.g. a 2x2GB "kit" with two 2GB cards) you would insert them into A1 and B1, not A1 and A2 (which would force single-channel memory operation). Is that how you originally had your two cards installed, before you upgraded? A1+B1?

Now in your upgraded setup, you've bought what you believed to be identical memory... which simply had a newer "version number" on it from the manufacturer. Personally I think that means nothing in terms of it being compatible with the older versions of the identical memory. I think the new ones should really be considered identical.

So now you have FOUR identical cards. I would have thought that if you inserted the new cards into the "second pair of dual-channel slots", namely A2+B2, leaving your original memory cards in A1+B1, that this should likely provide perfect operation. Sure seems like all four cards are "identical" and have the same internally recognizable part # from CPU-Z's output. The three screenshots look identical (although the "version" number is not shown) in every respect, but if there is even the slightest difference in the old pair and new pair I would think inserting them as A1+B1 and A2+B2, that this should certainly minimize or eliminate any possible effect.

With only three memory cards inserted, again I would put the old pair in A1+B1 and the new "orphan" in A2... as you've done (although I don't know if your original two card setup was A1+B1 to utilize dual-channel performance, or A1+A2 which would have forced single-channel performance).

But other than being caused by some other instability on this whole hardware setup (perhaps from other hardware), I do believe that since you've tried FOUR identical memory sticks it really shouldn't make a difference where you insert them, except that my own understanding is that for dual-channel operation you should be using A1+B1 for 2x2GB, and then A2+B2 for the upgrade to use the second 2x2GB purchase.

@ dsperber:

Hello. Regarding your comment...

"But other than being caused by some other instability on this whole hardware setup (perhaps from other hardware), I do believe that since you've tried FOUR identical memory sticks it really shouldn't make a difference where you insert them, except that my own understanding is that for dual-channel operation you should be using A1+B1 for 2x2GB, and then A2+B2 for the upgrade to use the second 2x2GB purchase."

...Yes, that makes complete sense to me! I did have the correct module arrangement when the 8 GB RAM was installed. I must of confused you, sorry! Now, the only slot I am not using is the B2 slot. The orphan RAM module is in A2 for me. I am thinking just maybe I should try the other way that is not recommended (A1 +A2) with one kit just to see what happens?!? You never know. Who knows? I may get single channel configuration now, but without this issue I am getting?!?

Is it possible the B2 *slot* on the mobo is defective, maybe???

It STILL could mean that a module in the NEW kit is bad and it just may be the other module I am not using now that is defective regardless if Memtest and Windows Memory Diagnostic tests indicated they all are okay? I have heard these tests are NOT 100% perfect.

I am also wondering if my slower RAM could be the reason for this issue????????????????????????

Let me ask you this... ....did YOU have to change the voltages and timings (like the DRAM or the northbridge) at all with your ASUS P5Q3 with 8 GB of RAM installed????????? PLEASE LET ME KNOW!





Let me bring up this and please let me know what you think. This is what I found about my RAM and where I found my mistake AFTER THE FACT:

I want to mention this...

First, let me throw out a tidbit and be MORE SPECIFIC about the memory I HAVE and the similar 'recommended' Corsair RAM that is recommend for all 4 slots or 8 GB:

A. What I am using (I HAVE) that is NOT recommended for ALL 4 slots in my mobo, only 2 slots max. is:
Corsair XMS2 4 GB 2 x 2 GB Modules DDR2 TWIN2X4096-6400C5

B. What is recommended to use with my mobo for ALL 4 slots for 8 GB:
Please see the attached QVL RAM Mobo chart for your help. You may have seen this at some point. Basically, my RAM is NOT recommended for 2 set of kits, but only 1 kit. [SOURCE: ASUS P5Q Motherboard User Guide E3790]

Take note of the 4 Corsair modules groupings in the chart. The two sets of kits I have is the same one and is highlighted in yellow. Like I said in my initial post, I misread the QVL chart before I purchased the second RAM kit and realized the mistake no too long ago.

Also...
*let me add some information to the charts so you can interpret A, B, and C for "DIMM Socket Support" mean since it is not explained here:

A = Supports one module inserted into either slot as a single-channel memory configuration.

B = Supports one pair of modules inserted into either the yellow slots or the black slots as one pair of dual-channel memory configuration.

C = Supports four modules inserted into both the yellow and black slots as two pairs of dual-channel memory configuration.

My highlighted memory is missing the "C" potential. That is what I am trying to do. I already have "B". I mean... ...and the real question is this... ...CAN I STILL TRY TO GET IT WORK FOR ALL 4 SLOTS (BOTH KITS) IF IT IS NOT RECOMMENDED OR CAN'T I?!?!? In-other-words, does "not recommended" mean that it MAY not work or NOT WORK at ALL?????????????????????????????
Hmmmmmm....


Please reply.

Thanks again!

montecarlo1987 said:

I did have the correct module arrangement when the 8 GB RAM was installed. I must of confused you, sorry! Now, the only slot I am not using is the B2 slot. The orphan RAM module is in A2 for me.

I see. Sounds perfect to me.

I am thinking just maybe I should try the other way that is not recommended (A1 +A2) with one kit just to see what happens?!? You never know. Who knows? I may get single channel configuration now, but without this issue I am getting?!?

But that would only be 4GB, and surely undesirable. No? Am I misreading what you're suggesting?

Is it possible the B2 *slot* on the mobo is defective, maybe???

I suppose so. It does seem like you have some kind of intermittent or flaky hardware issue, rather than a hard failure.

It STILL could mean that a module in the NEW kit is bad and it just may be the other module I am not using now that is defective regardless if Memtest and Windows Memory Diagnostic tests indicated they all are okay? I have heard these tests are NOT 100% perfect.

Possible, I suppose.

I am also wondering if my slower RAM could be the reason for this issue????????????????????????

WHAT "SLOWER RAM"???

Did I miss something?? I thought these were all four "identical" memory cards in all respects, other than for the minor "version number" difference on the newer ones.

Let me ask you this... ....did YOU have to change the voltages and timings (like the DRAM or the northbridge) at all with your ASUS P5Q3 with 8 GB of RAM installed????????? PLEASE LET ME KNOW!

I don't have 8GB of RAM installed. I only have 2x2GB=4GB installed, with 2GB in each slot A1+B1.

But the answer is NO, I did not change anything in my BIOS memory settings. I let the hardware figure out for itself what is right and proper. Every single one of my memory-related settings is set to "AUTO". I never changed one of them.

My memory is from Crucial (aka Micron) as has ALL of my memory been ever since I built my very first computer. The QVL chart in the ASUS user manual for the P5Q3 shows the exact "part number" for my Crucial memory that is presented by CPU-Z:



Again, I only have A1+B1 (slot #1 and slot #3 for CPU-Z) populated, with truly identical 2GB memory cards from Crucial as shown above. The two cards were purchased as a "2x2GB kit".





As far as your other thoughts and comments, I would still like to see the four slots on the SPD tab from CPU-Z. I'd thought all four memory cards were identical, but now I think you're saying that they're NOT identical... but rather have "different speeds".

A picture's worth 1000 words, so let's see those screenshots from CPU-Z.