Only 5.99 GB RAM usable with 12GB installed on MSI 990FXA-GD80

[#4]

I have installed the new MSI 990FXA-GD80 motherboard. Everything went fine. The system boots up as usual. First there was BIOS locking issue when entering into it. For that reason I updated the BIOS which have fixed this little issue. Now the only problem is with the RAM installed. Currently I have 12GB RAM installed on this motherboard. But the BIOS show only 5.99GB usable? I have 965BE X4 processor installed and overclocked it to 3.8GHZ with 2 x 4GB Corsair Vengeance 1600MHZ, and 2 x 2GB Corsair Dominator 1600MHZ. Is it the problem with 2 Dual Channels side by side?

[AkshatShetty]

It seems to me that you have overclocked the RAM. Try to remove any OC and load the BIOS Defaults setting. Now boot the system and see what you can get. However using 2 different Channel memory sticks is not recommended here. Also it is not the best idea to use 2 different manufacturer’s RAM on the same motherboard.

[LavinaD]

In 1600MHz slot my RAM is running so well, but they're designed for 1866. Then I would need to buy any 1833. So I'm on my 990FXA-GD80 and Corsair Vengeance 1866 C9 run 8GB without problems. There are also 16GB Vengeance kits. The Vengeance kits are optimized for AMD. Dual channel means that by putting two modules, the bandwidth is shared and increases from 64 bits to 128, having only one module lose that profit, but will run smoothly. And if you doubt, this "increase" in performance for the single-double channel, it cannot be possible since it has a significant impact.

[Mayoor]

What is strange is happening to you, I've owned a motherboard of your type and I've never had anything enabled in the bios to get the dual channel: are you sure that slots 3 and 4 are operating? Almost certainly the assembler has encountered your same problem and, quietly, I installed the ram in Single to avoid trouble. Try updating the bios and reset the settings (by updating the bios settings are reset automatically).

[JyotiT]

No 32-bit operating system for client computers can use more 4GB of memory. Another story goes for server systems 32 (Win2003/2008, Linux server versions, and others) which if you could use up these theoretical 64GB extra bits to process redirection report that the / PAE.

[Izna]

There is no way to use more than 3GB of RAM on a PC with Windows consumer 32-bit edition. The solution to use 4GB or more on a consumer PC is to upgrade to Windows 64-bit version: this is the solution recommended by Microsoft. Nowadays, many drivers and applications are 64 bit compatible, especially since the release of Windows 7. To use 4 GB or more RAM with Windows 7 64-bit, you must enable 'Memory Remap Feature' in the BIOS of your motherboard; this option is often disabled by default.

[Vance]

All recent programs work without problems, and no need to impose any compatibility mode. There is a software subsystem called WOW64 (Windows on Windows 64), present in 64-bit Windows operating systems, you need to turn the 32-bit applications on 64 bit systems. Personally, I was able to smoothly run everything I need, including a program a bit dated. Compatibility mode is applied only in some cases, very rarely in recent programs, and serves both for compatibility with 64-bit and for compatibility with Windows 7 itself. Some programs only work well with XP, for example, and these programs need to set compatibility mode to make them work properly under Windows 7.