Only 8 GB Ram recognised of 12 GB

Wordsworth said:

Mesa, I have a P6T and have upgraded the memory first from 3GB to 6, then 6 to 12. No problems. Go to Newegg and look up the Gigabyte GA-X58A-UD3R motherboard reviews, another very popular board. There you find some who have the missing memory problem, the vast majority do not. Same with the Asus P6T. This can be a problem with the X58 boards and the reasons can vary. Take a look at this page.

I hope the suggestions in this thread lead you to a resolution of your problem. I would first check the CPU and cooler mounting.

We who like to build our own systems must accept the fact that problems can arise.

Yeah after more research it looks like it's an x58 issue altogether. I have done the troubleshooting on that page and clearly there are more reasons this can happen as none of those are the cause of my issue. I have been a technician for many major corporations and the Department of Defense and have built thousands of systems. I have never encountered such an odd issue that seemed to have no definite cause.

Something weird I did notice is that if I remove the last 2GB chip from the C channel it registers 10GB. If I place another (confirmed working) 2GB chip in the last C slot it only registers 8GB instead of 12 for the whole system. Bad slot or bad chip that is weird behavior. For some reason having the last slot full not only doesn't add to the total but subtracts from it.

I know we don't live in a perfect world and I've had my share of PC issues to deal with but when there are this many people with issues it seems clear to me that it's a problem from the ground up. I wonder how many of these issues that were "solved" by that troubleshooting list actually had nothing to do with the troubleshooting in general. Removing the CPU causes a BIOS reevaluation whether anything actually changed or not for what it's worth.

Anyway, good luck to all of you with this issue. One day when we find the definite cause of this issue, I have a feeling it's not going to be anything on that list.

Something weird I did notice is that if I remove the last 2GB chip from the C channel it registers 10GB. If I place another (confirmed working) 2GB chip in the last C slot it only registers 8GB instead of 12 for the whole system. Bad slot or bad chip that is weird behavior. For some reason having the last slot full not only doesn't add to the total but subtracts from it.

I tried this, because 4 GB are too less... but it didnt work out...
Im really out of options here... does anyone have any other idea to fix this problem or atleast make my board recognize more then 4 gb?

You may have already tried this, but I had a similar problem and found that on the first cold bootup in the morning my computer would recognize just 4 of 6GB of RAM. If I turned off the computer (even right after the BIOS screen showed the wrong RAM total), I could boot up again and it always showed the correct total. It would then show the correct total all day no matter how many reboots. But the next morning on the first cold boot up, back to the wrong RAM total. Oh, and this was with both a Gigabyte board and now an ASUS board (just one of many fixes I tried).

I found huge threads on my ASUS motherboard forum, with this issue and all kinds of suggestions similar to those you've received. In most cases--where someone reported their fix--a change of RAM modules fixed the problem (even though the original RAM tests fine). In my case, I changed to another brand of RAM and it works perfectly.

I agree with MesA--there's a deeper problem somewhere in the i7 CPU memory controller and/or the X58 motherboards, and their sensitivity to identifying the RAM modules. It's a mess if you're one of the unfortunate ones that has this issue.