10-19-2011 10:34 AM - edited 11-03-2011 03:46 PM
My brand new Edge 11 (2545-3RG) that supports Max 2x2GB=4GB RAM was delivered with 2GB RAM in SLOT-0 (FRU 55Y3716, 2GB PC3-10600 DDR3-1333, which is the default, according to the hardware maintenance manual and the information on Lenovo Support site).
In order to upgrade to 4GB Dual channel, I put an identical second 2GB stick (also FRU 55Y3716) in SLOT-1.
The following happened:
- BIOS recognizes that 4096MB are installed.
- Win 7 x64 reports in System Properties that "Installed memory (RAM): 4GB (1.75GB usable)".
The size of the usable RAM, 1.75GB is 2GB in SLOT-0 minus 256MB allocated for the graphics.
- Windows applications can only "see" and use 1.75GB
- Special utilities, such as Speccy, do "see" both modules.
Speccy reports Total Memory Size as 4096MB. It is also supposed to display some detailed information about the memory in both slots. The information about the memory in SLOT-0 (here called Slot #1) contains, as expected, all details about Manufacturer, Part number, Serial number etc. However, the detailed information about the memory in SLOT-1 (here called Slot #2) is missing! Not even frequency in Max Bandwidth field is displayed!
The bottom line is that the memory in the second slot (SLOT-1) is unusable. To avoid speculations, there is 100% guarantee that all memory sticks are in full working order.
Has anyone else had this problem?
10-19-2011 10:47 AM - edited 10-19-2011 11:43 AM
I have experimented a lot and found a temporary workaround.
If you keep the original 2GB PC3-10600 DDR3-1333Mhz in SLOT-0 and put instead 2GB PC3-8500 DDR3-1066Mhz in SLOT-1, suddenly the second stick is correctly recognized everywhere, and everything works as it should.
As a curiosity, the opposite doesn't work at all and the laptop won't even boot!
Even if this workaround does work, the core issue still remains.
Lenovo, please provide a response to this hardware issue!
10-20-2011 02:25 AM
I have now discovered this document:
Note that, suddenly, PC3-10600 DDR3-1333 memory that was included with the laptop and recommended in the documentation as the default choice, is not even mentioned:
Lenovo, what is going on?