I've noticed a bit of instability when I try to use 8GB of RAM in my late 2008 unibody Macbook, it causes Memtest to crash and reboot my system. When I have a single 4GB stick installed, memtest passes fine.
My Boot ROM Version is: MB51.007D.B03
And I am running the latest version of Mountain Lion.
I'm currently using this Mushkin RAM:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820226015&Tpk=mushkin 976644A
System Information reads my RAM as 1333MHz, despite the product on the box saying 1066MHz, is that a factor?
Also, there is a backstory to this. I was recently on OSX 10.5, but decided to upgrade to 10.6 via DVD. My install kept failing telling me "OS X could not copy the system files". After much pain and the Apple Guru failing to install even with a network install, I thought I was forever doomed to be stuck in OSX 10.5 forever.
I read somewhere that some people had success with installing by using 1 stick of RAM. So since I tried 2x4GB and 2x1GB, I decided to try 1x1GB. And guess what, Snow Leopard installed! After that, I downloaded Software Updates then purchased ML on the App Store, but I needed 2GB of RAM to install it. So I put back in 2x4GB and the upgrade to ML succeeds fine.
I tried install XCode, and the Macbook crashed and restarted on me as it attempted to install. I then tried running Memtest and that also crashed. So that's when I try 1x4GB and the XCode installs fine and Memtest passes.
So I dunno, is my motherboard finicky such that it doesn't play nice with 2 sticks anymore? Is my RAM defective? Is my RAM speed reported at 1333MHz problematic?
Also, prior to any upgrades (while in 10.5), I ran Memtest86+ for a good hour with no errors with the 2x4GB and 10.5 never crashed on me. I wonder if ML is being finicky.
