my system shows 14GB. I had 6 GB ram then recently installed a 12GB (4 x 3) kit. If I go into the BIOS during startup and go to configure my RAM speed, it shows 18GB.
The limit for windows 7 home premium is 16GB so the other two won't show up. You will need to upgrade you windows install unfortunately.
Should have mentioned: Also I just look in the bios during startup to see the RAM, then at desktop I check the system amount, it says 18gb. But if I restart and don't go into the bios screen, it says 14GB.
I just updated and upon restart it showed 18GB in the windows information box. Then I restarted to setup bios for my previous overclock and now it says 14GB again :/ Cpu-Z and the bios both show Memory size as 18432 MBytes
And here we go again, good old X58 memory detection bug. Play with IMC voltages, reseat memory, reseat CPU, check if CPU cooler is not overtightened. If nothing helps, bad luck, it's X58. In our case RAM size was randomly detected between 8, 10 and 12GB with 6x2GB modules (SPD reported all 6 of them). If you go to Resource Monitor and click to the Memory tab, yo will have most of those 4GB listed as "Hardware reserved" in the chart there, with grey color.
It just confuses me as to why it detects it in CPU-Z, but not anything else. Then sometimes after I boot up it will show all 18GB then I have to restart for an update, back to 14GB. The resource monitor shows: Is it a big enough technology gap to upgrade to today's CPU's, motherboards, etc...
Ok, that is a new one for me, it usually comes up as Hardware Reserved. Still, the point stands - it is the useless memory controller on Nehalem unfortunately. Core 2 had it absolutely useless (anything more than 2 modules were pure random if it will work or not), Nehalem had this "i won't detect your RAM sometimes" behavior, the first absolutely problem free platform in this regard is unfortunately for you Sandy Bridge and newer. CPU-Z detects the RAM because it reads SPD, it doesn't ask BIOS/OS about the RAM at all. The solutions that resolved this problem were listed before, but don't believe me, believe others : https://www.google.com/search?q=full+amount+of+ram+not+detected+x58 Even EVGA has a checklist to check for X58 boards before even contacting support : http://www.evga.com/support/faq/afmviewfaq.aspx?faqid=58783 In short - it is common for X58 systems to detect only 3-4 of 6 modules.
Dropped my IMC Voltage by one unit (to ~1.345) in the BIOS and all is well. 18GB recognized! You get a hug faugusztin. (+rep) EDIT: Kept searching incase it happens again and also found you can change your DRAM Timing: Reference Cycle Timing to 100 clocks. Then keep in mind the QPI might have to be upwards of 1.4/1.5 depending on how large of a RAM kit is installed. SOURCE: http://www.youtube.com/watch?v=R_9MwkZ8cjs
