2x 2.8GHz Quad core ram problem. I Bought the 3,1 cMP and it had 32g (4x8g modules 667) ram running High Sierra on a 240G SSD. I used DosDude to install Catalina on one of my drives. and all was well. I saw on EveryMac.com that OWC says it will run on 64g. I had 16g (2x8g modules 667) and added it and it ran great in both OS's. I ordered 16g more (2x8g modules 667) and they just came in. Catalina sees the 64 but drags and hangs and it won't even fully boot in High Sierra, the progress line goes all the way on the apple boot screen but then hangs from there. I can revert back to the 48g and all is well. I understand 800 ram is what I should be using but it had 667, I had a couple, so I didn't want to mix.
I tried going a little further with the High Sierra drive. with these new and old sticks, they are all 667. I tried one riser at a time, two old and two new, mixed old and new, then just old then just new. 4 at a time just top, then I repeated it on the bottom. I then tried just pairs on the bottom, sockets 1/2 then 3/4, old and new. It wasn't until I tried pairs only in the top front most slots that the power button started blinking. With the bottom riser pulled, any pair I tried did not work in the front two upper slots alone. Although when I tried all four upper slots using any configuration old and/or new, they all were seen and showed under "about this mac" under memory. Is it the ram? The sticks all work in any configuration old/new in any position, either riser using only one riser at a time. Is it the riser? All four slots show with any four sticks installed. I'm stumped.
As I type this I'm waiting for El Capitan ( I read this was the original OS for the 2008? ) to load on a spare drive. I'm not sure if it will run 64g?
Thanks for any help.
I tried going a little further with the High Sierra drive. with these new and old sticks, they are all 667. I tried one riser at a time, two old and two new, mixed old and new, then just old then just new. 4 at a time just top, then I repeated it on the bottom. I then tried just pairs on the bottom, sockets 1/2 then 3/4, old and new. It wasn't until I tried pairs only in the top front most slots that the power button started blinking. With the bottom riser pulled, any pair I tried did not work in the front two upper slots alone. Although when I tried all four upper slots using any configuration old and/or new, they all were seen and showed under "about this mac" under memory. Is it the ram? The sticks all work in any configuration old/new in any position, either riser using only one riser at a time. Is it the riser? All four slots show with any four sticks installed. I'm stumped.
As I type this I'm waiting for El Capitan ( I read this was the original OS for the 2008? ) to load on a spare drive. I'm not sure if it will run 64g?
Thanks for any help.
. I hope yours is a joy.
