if you insert the DDR2 800Mhz ram into the board... it will run at 667mhz only..
DDR2 ram are downward clockable.. means.. if you hve 800mhz, itcan clock back to 667 or 533 ..
you may try inserting the ram.. if it works mean... great.. but if there is a beep sound.. try reseting the bios and try again.. if not.. don't
We have the same mobo....i have the same dilemma as you do....2GB ram wanting to go to 4GB....suggest you read this persons story at http://communities.intel.com/thread/4186 under name: francisxavier.p
Personally, I am gonna do what I can, hoping the 4GB will work....not a pro, but I know a 1/2 doz or so who are tech pros...will find out, that is for sure. the reason I am so adamant about it is because I am just setting this up for my sweets and she needs that 4GB with what she does.....so, we are at least gonna give it a whirl. any-who, recommend you read that other individuals post at link I gave you....if I hadn't read it for myself, don't think I would even be trying at all....but now, I at least have hope....and have come to the conclusion that not all is as said. Some things work defying the odds.
Best of luck to you w/ your mobo and ram.
Today I replaced my (2 x 1 GB 667 MHz) DDR2 with (2 x 2 GB 800 MHz) DDR2 ram modules on Intel D945GCNL motherboard (with latest BIOS update = NL94510J.86A ver. 0036)
& the RESULTS are:
Bios: Shows 4096 MB of ram running at 667 MHz. (that's the max. ram FSB supported by motherboard)
OS: (Win 7 SP1 64bit) Shows ram = 4.00 GB (3.24 GB usable)
Task Manager: In performance tab under physical memory shows Total memory = 3317 MB.
Hence, i have no idea what francisxavier.p is talking about as (in any case) the real usable memory still remains about 3.24 GB.
As proof see the following snapshots:
My advice is to upgrade upto 3 GB ram max. that's it instead of ruining your money on 4 GB ram.
If francisxavier.p has motherboard with BIOS NL94510J.86i ver. 0005 (iPAT support) then may be his PC is running on 4 GB usable memory but I cant confirm that.
System Configuration Details:
Mother Board: Intel D945GCNL
Processor: Intel Core 2 Duo E4600 @ 2.40 GHz
RAM: 2 x 2 GB DDR2 @ 800MHz (Running @ 667MHz)
OS: Microsoft Windows 7 Ultimate SP1 64bit