windows 7 x64 memory problem: "4.00 GB (1.99 GB usable)"

G

grenadier

Limp Gawd
Joined
May 5, 2002
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494
Just installed my new p7p55d pro & i5 750 combo and my 32-bit vista system info was showing "4.00 GB (1.99 GB usable)" - then did a fresh install of windows 7 x64 thinking that the new os would solve the problem. With windows 7 x64 installed I've still got exactly the same 4GB/2GB problem.

CPU-Z is detecting both dimms (slots 1 & 3) and is listing my memory size as 4096, which is correct. CPU-Z is telling me I'm running single channel memory though.

Any idea what my problem is?
 
sounds like one of your memory modules isn't really enabled? try a different config if possible.
 
First, and most obvious, make sure both DIMM's are fully seated in their respective slots. Second, make sure your RAM voltage and timings are set to manufacturer's specs. Try raising CPU VTT voltage a bit as well if manually setting voltage and timings doesn't help. Last, make sure your CPU is seated correctly and there are no bent pins in the socket. The i7/i5 CPU's have and their memory controller integrated into the CPU and if the wrong pins are bent or not making proper contact with the CPU you can experience this type of problem. Another potential cause is a heatsink that is tightened down too tightly causing the traces between the socket and DIMM slots to not connect.
 
criccio said:
Why would that matter?
Click to expand...

I think he's thinking that it is memory that is being allocated by the system for hardware addressing. The OP stated he was running a 32 bit system, so that would make sense. In this case, however, it doesn't. The OP also stated that the same thing happens under Windows 7 64 bit, and also that CPUz is reporting the memory running in single channel mode, so something else is going on here besides the usual disappearing memory due to 32 bit OS limitation.
 
Ken Clean-Air System said:
I think he's thinking that it is memory that is being allocated by the system for hardware addressing. The OP stated he was running a 32 bit system, so that would make sense. In this case, however, it doesn't. The OP also stated that the same thing happens under Windows 7 64 bit, and also that CPUz is reporting the memory running in single channel mode, so something else is going on here besides the usual disappearing memory due to 32 bit OS limitation.
Click to expand...

Yea thanks, lol. I was just trying to call the guy out on not reading the thread because the OP clearly said he tried a 64bit OS with the same effects.
 
I was having this issue and after spending hours troubleshooting the voltages and crap I reseated my CPU which ended up fixing the issue. Who would have thought?

Try reseating the CPU.
 
There's 1 video card in my rig. Also I've tried turning memory remapping on / off and it doesn't help anything.

Both the bios & Memtest 86 are detecting a pair of 2GB dimms - one in each of the populated dimm slots. Both are also listing total system memory as 2GB... so maybe this isn't an OS issue. I'm going to move to the motherboard forum. Thanks for everyone's help.
 
First, press Windows Key + Pause Break and make sure it says

Installed Memory (RAM): xxxx
System Type: 64 bit Operating System.

Second. Absolutely as Clean Air pointed out, INSURE that your memory modules are set to the right timings, bus frequency and voltage. Some boards auto detect well, others do not.

Third. Look for any type of memory remapping/hi memory option in the bios. Occasionally boards still come with this ancient switch that needs to be toggled on.

Last. Flash the bios to the latest n greatest version.
 
1. what does the windows memory test show? Windows may have disabled memory due to errors
 
I have the P7P55D and I can only see 3 GB of my 4 installed (2x2). Not sure why. x64 Windows 7 sees 4GB.

Would memtest help?
 
criccio said:
Your not sure why you can see all 4GB with a 64bit OS? Kind of obvious, no?
Click to expand...

I can see where skimming would read that way, but there are two periods in there ;) (emphasized below):

I have the P7P55D and I can only see 3 GB of my 4 installed (2x2)<period> Not sure why<period> x64 Windows 7 sees 4GB.
 
take a screen shot of your Computer properties and post it.

does all your ram show in the bios or on boot?
 
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