PC only using 2 out of 4 Dimm slots.

[xXDestroyer27Xx]

For some reason my PC is only using 2 out of the 4 Dimm slots. It sees all of my RAM but isn't using all of it. I have 12GB of RAM but my PC and BIOS only shows 8GB. I have an early 2012 Dell XPS 8500 with an Intel Core i5 3350P, 12GB of RAM, Windows 8 64-bit, and an Nvidia Geforce GTX 660. Help would be greatly appreciated.

 

[turkey3_scratch]

Either you have some broken RAM or a broken RAM slot. I am assuming you have 3 sticks and 4 DIMM slots. Try using only one stick and see which one is bad.

 

[brispuss]

Try ONE DIMM at a time and in different slots as well. This will help determine which DIMM and/or slot is/are faulty.

 

[xXDestroyer27Xx]

Either you have some broken RAM or a broken RAM slot. I am assuming you have 3 sticks and 4 DIMM slots. Try using only one stick and see which one is bad.

All of the RAM is fine and the DIMM slots are fine too. I have 2 4GB DIMMs and 2 2GB DIMMs. When I put them together it seems to not work.

 

[spentshells]

Are you staggering the ram in the appropriate slots? Just a shot in the dark.
Is all the ram the same speed?
What ram sets are you using? Make and model please.
Perhaps the voltage settings are too far apart.
It's also possible the dell bios isn't allowing two separate speeds to function at the speeds of the lower clocked kit.

Ill assume you have tested with only the 4GB installed. If not do that and test it out.

 

[turkey3_scratch]

Either you have some broken RAM or a broken RAM slot. I am assuming you have 3 sticks and 4 DIMM slots. Try using only one stick and see which one is bad.

All of the RAM is fine and the DIMM slots are fine too. I have 2 4GB DIMMs and 2 2GB DIMMs. When I put them together it seems to not work.

I highly doubt you tested it in the 15 minutes it took you to respond. That would require about 6 different combinations of RAM/slots. Did you do exactly the above?

 

[xXDestroyer27Xx]

Are you staggering the ram in the appropriate slots? Just a shot in the dark.
Is all the ram the same speed?
What ram sets are you using? Make and model please.
Perhaps the voltage settings are too far apart.
It's also possible the dell bios isn't allowing two separate speeds to function at the speeds of the lower clocked kit.

Ill assume you have tested with only the 4GB installed. If not do that and test it out.

The RAM is all the same speed, its 1600MHz. Im not sure what model it is, all i know is that it came with the computer when I bought it and it used to work. I checked and the Voltage is the some on all of them. I also have tested all of the RAM. I would put only the two 2GB Dimms and it would show 4GB and the same with the 2 4GB Dimms.

 

[xXDestroyer27Xx]

Are you staggering the ram in the appropriate slots? Just a shot in the dark.
Is all the ram the same speed?
What ram sets are you using? Make and model please.
Perhaps the voltage settings are too far apart.
It's also possible the dell bios isn't allowing two separate speeds to function at the speeds of the lower clocked kit.

Ill assume you have tested with only the 4GB installed. If not do that and test it out.

Either you have some broken RAM or a broken RAM slot. I am assuming you have 3 sticks and 4 DIMM slots. Try using only one stick and see which one is bad.

All of the RAM is fine and the DIMM slots are fine too. I have 2 4GB DIMMs and 2 2GB DIMMs. When I put them together it seems to not work.

I highly doubt you tested it in the 15 minutes it took you to respond. That would require about 6 different combinations of RAM/slots. Did you do exactly the above?

This has been a problem for quite some time. I have tested it before. It didn't just appear yesterday.