Only 4GB in Activity Monitor instead of 8GB

[n8210]

Geekbench and System Profiler shows that I have 8GB ram. I have 4 sets of these, taken from system profiler:-

BANK0/DIMM0:

Size: 2 GB
Type: DDR3
Speed: 1338 MHz
Status: OK
Manufacturer: Kingston
Part Number: 9905403-011.A03LF
Serial Number: 0x4f274065

The same for Bank2,3 & 4. Not sure if it is related, but I'm booting into 64-bit SL. Not sure if I'm running on 8GB or just wasting 4GB in my system. Appreciate some kind assistance. Thank you.

 

[n8210]

After a day of searching around, I still can't understand why only 4GB. I have downloaded TinkerTool, and it's Diagnostic tells me RAM usable by the operating system is only 4GB. Anyone, please.....

 

[MacMan]

After a day of searching around, I still can't understand why only 4GB. I have downloaded TinkerTool, and it's Diagnostic tells me RAM usable by the operating system is only 4GB. Anyone, please.....

Are you using Chameleon from MultiBeast as your boot-loader?

 

[n8210]

Thanks MacMan for your kind assistance.

Yes, used Multibeast version 2.0.2. But I have just discovered this in bios:

1)System memory: Usable size = 4088MB; &
2)Memory remap feature: PCI MMIO Allocation = 4GB to 3328MB

I have updated to the latest bios. What can I do now on my Asus P7P55 LX board to make it read 8GB? The board has MemOK feature, it does not show/indicate any problem. No beep sound during boot up as well. I don't think I've installed the ram wrongly.

 

[n8210]

I've solved my ram problem. Turns out the 4 sticks of ram cannot work with each other, although all 4 are Kingston, DDR3, 1333MHz. In fact, 3 sticks are similar while the 4th which is also Kingston, but has a different hologram sticker. And if you say that's the odd one causing problem, well no. This is what I did:-

First two sticks 2x2GB coupled with another brand new set Corsair 2x2GB = it works, total 8GB shows up in bios and in activity monitor.

Second two sticks with the different hologram 2x2GB coupled with Corsair = it works too, 8GB in total.

But if you put all 4 sticks of Kingston together = it does not work, only 4GB ram.

Any one knows why? I sure don't.

 

[Lnx2Mac]

Make sure you are pairing correctly your identical sticks on separate channels...

 

[n8210]

They are all Kingston DDR3 1333MHz!!

 

[Lnx2Mac]

Even if they are all Kingston DDR3 1333MHz, the timings and chip layouts might be different...
After carefully re-reading your post, I now realize you might have 3/1... Sorry about that.

 

[n8210]

Actually the odd one (with the different hologram) was the one that originally came with the system, provided by the shop. I recently purchased 2 sticks and of course they are the same. D*** shop.