Memtest86+ not recognizing all RAM.

[Sandstorm3000]

So ive had this problem for maybe a week now, since ive resetted CMOS/BIOS my PC can only use 3GB of its full 4GB. So i decided to run memtest86+

Memtest sees two sticks, both 2048MB DDR2-800MHz followed by a serial number.

But it is only testing 3GB of the full 4GB, i have absolutely no idea or even a clue how this is possible. Could it be that half a stick is faulty? (which i never heard of)

 

[razerg]

"Half a stick" cannot be faulty. If you have 32bit windows OS then it will be able to use max 3.75GB i think. Though i've seen it using only 3.25GB sometimes.

 

[Sandstorm3000]

"Half a stick" cannot be faulty. If you have 32bit windows OS then it will be able to use max 3.75GB i think. Though i've seen it using only 3.25GB sometimes.

Im using Windows 7 ultimate, 64bit.

 

[razerg]

Is the whole 4GB recognized by BIOS? Did you test individual ram sticks or just both of them. Also you may not put them in correct slots on your motherboard.
Again try memtest on each stick individually then see what happens. You may have a bad stick.

 

[Sandstorm3000]

Is the whole 4GB recognized by BIOS? Did you test individual ram sticks or just both of them. Also you may not put them in correct slots on your motherboard.
Again try memtest on each stick individually then see what happens. You may have a bad stick.

The whole 4GB is actually not recognized by the BIOS, its '''sees'' about 3007MB (not sure but somewhere between 3000-3009MB), ill test the sticks individually. I will also try using the other available slots.

 

[razerg]

Okay, you do that. If it turns out that one of the sticks is causing the problem not both of them then bring it over to a friend and see if it works in his PC properly. If it doesn't then replace it. Also, did you do anything in the BIOS before you reset it that could possibly cause the problem?
Usually ram slots are marked with letters near slots such as DIMMA1, DIMMA2, DIMMB1, DIMMB2 or with different colours. Make sure you put sticks in A and B slots first (so you would put in DIMMA1 and DIMMB1 OR DIMMA2 and DIMMB2)

 

[Sandstorm3000]

Okay, you do that. If it turns out that one of the sticks is causing the problem not both of them then bring it over to a friend and see if it works in his PC properly. If it doesn't then replace it. Also, did you do anything in the BIOS before you reset it that could possibly cause the problem?
Usually ram slots are marked with letters near slots such as DIMMA1, DIMMA2, DIMMB1, DIMMB2 or with different colours. Make sure you put sticks in A and B slots first (so you would put in DIMMA1 and DIMMB1 OR DIMMA2 and DIMMB2)

I tried both sticks individually, both showed 2048mb available when inserted one at the time, whenever i put in both i only get 3000mb, the weird thing is, my bios shows 3gb, memtest shows 3gb but windows says there is 4gb installed but also uses just 3gb.

I don´t know what caused the problem, it must be a setting in my BIOS but i don´t have a single clue what setting it would be, the problem occured since i resetted the BIOS. (to remove the OC on my CPU which caused other problems)

The sticks are in slot #1 and #3, in this way they should operate in dual channel mode. (both slots used are blue, the white slots are free.)

 

[razerg]

Well they are in correct slots. With that out of the way it is probably something with windows, or BIOS. Do you remember have you changed any values in BIOS besides clock speeds? And how do you know your PC uses 3GB when you said it shows 4GB is installed? Though you can try this, go to msconfig (type msconfig in start) then when opened go to "boot" tab, click advanced and make sure maximum memory is ticked. Then hit ok, restart and see what happens.
If the problem persists, then could you give me the correct model of your ram sticks?

 

[Paperdoc]

So, you reset the BIOS. ONE of the settings in BIOS Setup controls just how RAM is organized. AND the tricky part is, RAM on your video card also must be included.

Now, 32-bit OS's can only address 4GB of RAM in all forms, and that must include the video card RAM. The default settings in BIOS (which is what must now be in place because of your reset) will insist that whatever RAM is on your video card must be within the 4 GB range to be sure that even a 32-bit OS can work. The BIOS does not know that you are using a 64-bit OS yet. Thus it limits you to using LESS than 4 GB of main RAM. For example, if your video card has 1 GB of on-board memory, your mobo can only allow 3 GB of main board RAM to be used by the OS.

The solution is to find in BIOS Setup the controls used to tell it to allow video RAM to be located above the 4 GB barrier. THEN it can allow the mobo to recognize the video RAM above that address limit, and allow it to use all 4GB of main board RAM.

 

[Sandstorm3000]

Well they are in correct slots. With that out of the way it is probably something with windows, or BIOS. Do you remember have you changed any values in BIOS besides clock speeds? And how do you know your PC uses 3GB when you said it shows 4GB is installed? Though you can try this, go to msconfig (type msconfig in start) then when opened go to "boot" tab, click advanced and make sure maximum memory is ticked. Then hit ok, restart and see what happens.
If the problem persists, then could you give me the correct model of your ram sticks?

I have changed nothing in the BIOS besides some CPU settings. I am already sure there is only 3GB because one game i max it out a lot of times, which i usually don't, when i go play a game now i close all unnecesairy programs so i have enough RAM available.

The exact model is Corsair XMS2 - 800MHz DDR2.

Ill try the MSCONFIG thing in a few minutes

 

[Sandstorm3000]

So, you reset the BIOS. ONE of the settings in BIOS Setup controls just how RAM is organized. AND the tricky part is, RAM on your video card also must be included.

Now, 32-bit OS's can only address 4GB of RAM in all forms, and that must include the video card RAM. The default settings in BIOS (which is what must now be in place because of your reset) will insist that whatever RAM is on your video card must be within the 4 GB range to be sure that even a 32-bit OS can work. The BIOS does not know that you are using a 64-bit OS yet. Thus it limits you to using LESS than 4 GB of main RAM. For example, if your video card has 1 GB of on-board memory, your mobo can only allow 3 GB of main board RAM to be used by the OS.

The solution is to find in BIOS Setup the controls used to tell it to allow video RAM to be located above the 4 GB barrier. THEN it can allow the mobo to recognize the video RAM above that address limit, and allow it to use all 4GB of main board RAM.

My graphics card indeed has 1GB of VRAM, but i just can't find this option in the BIOS. What you are saying does sound like that is the problem.