4GB Memory Unusable

I finally got my new I7 980X CPU today so went to fire up my newly built PC but the POST screen only shows 4GB of memory. Re-seated the chips and still only 4GB. Memtest86+ V4 shows all 4 sticks of 2GB Corsair ram as present but only says 4GB as well.

Installed Windows 7 and it says 8GB installed. 4GB usable. This is the 64bit version so I am expecting to get the whole 8GB.

Anyone know who or what is holding the other 4GB to ransom and what do I have to pay to get it released?

It is brand spanking new all round. POST shows 4GB. Have everything in the BIOS set to auto so timings should be pretty loose as I wanted to get it working before starting to tweak. The memory chips speeds are rated much higher than what they are actually running at (needed room to move).

Will try the CPU cooler. It was a dog to get on. Artic Cooler Pro and has two screws to tighten but you cant see them to put them in.

veldthui said:

It is brand spanking new all round. POST shows 4GB. Have everything in the BIOS set to auto so timings should be pretty loose as I wanted to get it working before starting to tweak. The memory chips speeds are rated much higher than what they are actually running at (needed room to move).

Will try the CPU cooler. It was a dog to get on. Artic Cooler Pro and has two screws to tighten but you cant see them to put them in.

Check what max memory is set to in msconfig. (type msconfig in search). It should be unchecked.

Besides trying Smarteyeballs good advice I would try the following procedure.

I would try shutting down the machine, unplug power from PSU and drain power by pushing start button. Remove half the Ram from every other slot. Restart the machine check to make sure all 4GB are picked up by Windows. Shut down again and repeat procedure of draining power, install one stick at a time repeating the same procedure each time and see if Windows picks them up each time you restart.

I tried the cooler. When I loosened it off it only POSTed 2GB. When I tighten it back up regardless of how much it still only POST's 4GB. What is strange is that MemTest86 and Windows both show 8GB there. Windows 8GB installed, 4Usable. MemTest86 shows all 4 stcks of 2GB but again only tests 4GB of it.

Cant see any options in the BIOS that would disable the mem. The timings are 7-7-7-24 @ 2020mhz. Well within the specs of them.

veldthui said:

I tried the cooler. When I loosened it off it only POSTed 2GB. When I tighten it back up regardless of how much it still only POST's 4GB. What is strange is that MemTest86 and Windows both show 8GB there. Windows 8GB installed, 4Usable. MemTest86 shows all 4 stcks of 2GB but again only tests 4GB of it.

Cant see any options in the BIOS that would disable the mem. The timings are 7-7-7-24 @ 2020mhz. Well within the specs of them.

Here's a semi-random suggestion:

Your system must support triple channel memory. What happens when you use only 3 DIMMs, in a triple channel configuration?

The system is a DDR3 system with 6 DIMM slots. It says to stick memory into slots 2,1,3,5 for 4 modules. I stuck one moduke in 1 and it would not POST. 2 modules in 1 & 3 and it posted with 2GB. 3 modules in 1,3,5 and it posted with 4GB. I then tried slots 4 and 5 with more modules and got the 8GB. However it will work with anything in slots 1 & 2. It is detected but it wont POST the size and it cant be used.

I may have a faulty motherboard. I have had one BSOD as well with the 8GB but I was playing around with the timings and it may not like the memory in the other slots. The manual says 1 first but it is out of action.