8GB of RAM in a Unibody Macbook Pro? Yes, but…

I know all this Mac stuff is off-topic for SharePoint readers but I get a lot of comments from other Mac users here so I thought I would post my experiences on a confusing topic. When I bought the new Unibody Macbook Pro back in October I did so with the hope that I would be able to install 8GB of RAM in the machine for virtualization purposes. I knew it wasn’t officially supported but I was hopeful; as DDR3 4GB SODIMM’s weren’t widely available yet I couldn’t really test it out at the time.

I now have conclusive results for other Macheads out there. The first generation Unibody MBP’s – 2.4GHz, 2.53GHz, and 2.8GHz models – do not reliably run any more than 4GB of RAM. Some people have had success with 6GB (one 4GB chip and one 2GB chip) but, using Apple’s own ridiculously overpriced 4GB chips, I could not get my 2.53 model to stabilize above 4GB.

Recently, Apple bumped up the specs on the 15” MBP’s to match the new 17” models; specifically, they now only offer the 15” in 2.66GHz and 2.93GHz models (the 2.93 can only be ordered online). Assuming that the firmware on the 15” had been updated to match the 17” board I bought a new 2.66 model and slapped the 4GB RAM chips into it. Success! I am now running 8GB on my 15” Unibody (and yes, I’ve stressed it up over 7GB utilization using VMWare Fusion and it works fine).

Somewhere along the line in my research I found a thread indicating that the motherboard revision numbers changed from the first generation to the second generation but I can’t find the thread now and I don’t see any markings on the greenboard to confirm or deny this. All I can tell you is this:

* The 4GB limitation in the first generation Unibody’s is *not* a Leopard issue. Leopard works just fine on my new 15 and the 17’s.
* You *must* have the 2.66 or 2.93 model to run 8GB (unless Apple releases a firmware update to fix this).
* SOMETHING is different between the first gen and second gen, either the actual hardware or the firmware, but there is no doubt that they’re not the same.

Also, I think you would be better off waiting for RAM prices to come down or, if you must have 8GB now, buy it from Crucial, OWC, etc. Apple’s price is just nonsensical (I had a credit to use so it didn’t hurt me quite as bad; full retail price is $1,200 in the US).

Now back to our regular SharePoint programming…

UPDATE: Not sure why but someone asked for a screenshot to prove this. You can’t really tell it’s a 15" (unless that’s what MacBookPro5,1 means) so you’ll just have to take my word on that.

Apparently, we still have some skeptics in the audience. Here’s a screenie of Activity Monitor showing nearly all 8GB being used. And, yes, this *IS* a 15" MacBook Pro and *not* the 17" version.