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I had 4GB of RAM and just installed another 4GB. When I go to my computer's properties I see it recognizes all 8GB but I'm still only able to use 3.47GB.

My motherboard is an Asus P7H55-M which is supposed to handle up to 16GB. I'm running Windows 7 Enterprise 64-bit as well, so what might be causing this? How can I use all 8GB?

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How are your RAM modules arranged, e.g. what capacities are each of them, what speeds are they and what slots are the installed into? – Windos Aug 15 '11 at 21:09
does the BIOS detect all 8G? – Earlz Aug 15 '11 at 22:06
Post a print screen of your System Properties – Canadian Luke Aug 15 '11 at 22:56
You'll have to make sure your mother board, chipset, CPU and BIOS supports the configuration of your RAM. Some cannot accept RAMs that use too many banks. – Aug 15 '11 at 23:13
Just out of curiosity, how do you know it can only access 3.47GB? Where are you getting that information from. The reason I ask is that 3.47GB is the exact size of the windows 7 iso file which is a little suspicious. – Col Aug 16 '11 at 20:39

Have you done a bios flash recently? Start with that. Get your bios to the most current version.

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Several tips to follow when adding ram, you should also trouble shoot the new RAM module by testing it in isolation (only have it connected)

  1. Install the RAM in order of size, largest first, review motherboard manual
  2. Ensure firm connection
  3. Pair up ram modules in their corresponding pair channel
  4. Update BIOS
  5. Ensure the modules are of the same type, and compatible


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up vote 1 down vote accepted

On the bios I saw this as well as in the OS that all 8Gbs are recognized but not all of the memory is usable. I updated the bios and also flushed CMOS but it didn't do any good

Eventually I just started playing with the positioning on the chips, and every time I got a new and different result, until I got an order that somehow made all 4 of them work togeather.

Right now they are in a mix, meaning every new stick is paired with an old stick and not with his rightful match, and somehow

(By the way, all chips are Kingston 2GB and same Hz, just some old (and from china) and some new(and from Taiwan))

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Are you sure that your memory sticks are free of errors? If one of the sticks is bad, the BIOS will block off the address range above where it finds the error. That would explain why you get a different result each time you swap around the sticks, since the bad stick will be in a different position each time. Run memtest86 to help narrow down which stick is bad.

Another possibility is that the motherboard itself is bad. I've seen it before, and it causes erratic results with different RAM sticks.

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all 8Gbs are now working and loading just fine now, none is blocked. – Roy Toledo Aug 22 '11 at 6:54

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