I am looking to add more RAM to my 2010 Polycarbonate unibody MacBook. It has Core 2 Duo with Nvidia 320M chipset.
I've read that this model can run 16GB RAM (even though Apple states otherwise), and I've seen people running it with 1333MHz sticks instead of the 1066MHz ones as well. macOS reports the memory to be running at 1333MHz as well.
Now my question is, can it run 1600MHz sticks as well? It's much easier to get those sticks nowadays.
Best Answer
The people at OWC do this sort of thing on a common basis -- test to see what combinations of memory will work.
If I've figured your mac correctly, this page: https://eshop.macsales.com/shop/memory/Apple_MacBook_MacBook_Pro/Upgrade/DDR3_White
says that the most you can have is 2 8GB sticks.
Haven't done it, so take this with a grain of salt, but most of the time using a faster stick is tolerated. It won't run at the higher speed.
There are few cases where some odd combinations of memory work. One instance where a mac could use a 4GB chip in the second slot, but only a 2 in the first. I've also heard of combinations that had flakey performance with certain size chips -- would boot, but crashed at random intervals. I suspect that the chips drew more power than the main board could easily supply, and so were running at a marginal voltage.
More ram isn't a panacea. Fetching data from ram into cache still takes hundreds of CPU cycles. At one point I analyzed a raft of test results spanning several years from tests on Tom's Hardware Site. The major determinate of bench mark tests was front side bus speed -- usually a divisor of the clock speed. This sometimes meant that under clocking the CPU could allow a lower divisor and a higher FSB.
Some apps are greedy. Chrome on my mac will just use whatever its available. As I speak, Chrome is 1 G, and has 14 helpers ranging form 2 GB down to 400 MB.
Certain apps can really use more ram. Photoshop. Final Cut Pro.