Installing 8GB RAM in late '08 Unibody 13,3" MacBook gives 3 beeps

Return the Corsair ram, it soesn't work well in Macs. Buy from either Crucial http://www.crucial.com/ or

OWC http://eshop.macsales.com/

Stay away from Corsair, Kingston, Centon and pretty much another's not sold by one of the two vendors I listed.

Doesn't crucial ship internationally? Those are really your best bets. The other brands even though their specs seem to match, are oftentimes misrepresented, 1066 mHz ram will actually be 1068mHz. Their specs just aren't up to Apples standards.

http://www.crucial.com/eu/ is in England.

Two comments, if I may. I too tried adding 2 x 4 gB to a mid 2010 Macbook Model ID 7.1 without success. The best I have achieved is 1 + 4 - see below. (Original config was 2 x 1 gB). Each of the 4's work individually, but not together.

I bought my RAM off a Amazon link, and I cannot complain since the RAM modules do work. It's my Macbook that won't do what others say it can.

Because of exactly the reason I mentioned above. Do either of your new ram modules work by themselves without the addition of the original 1gb module? My guess is no. It works with the original because the original module forces the system to clock down the new module that on it's own runs at the wrong speed. The other manufacturers state that their ram works but Crucial and OWC guarantee it.

If you bought your RAM at a place that also sells PC RAM you may have gotten mislabelled RAM. PCs can handle different RAM speeds so they’ll often label higher speed RAM as a lower speed rather than make two different speeds of RAM. But Macs are much more picky. They require a RAM stick to be exactly 667mhz not 675mhz or 800mhz. The way to tell is to put one of your old RAM sticks in and it will force the new RAM to run at the correct speed.

This is from one review of PNY RAM:
"These modules are actually 800Mhz. PNY no longer makes or sells 667Mhz modules. Not all computers that require 667Mhz are compatible with 2 800Mhz modules. They refuse to down clock properly. This is especially true with a number of Core 2 Duo MacBooks. Spoke to PNY support, they flat out told me that yes, they sell 800Mhz modules in 667Mhz packaging. If you RMA a module that is 667Mhz (or supposed to be 667Mhz) they will replace it with an 800Mhz module as they no longer have any 667Mhz SODIMMs, not even for RMA replacement!"

Do either of your new ram modules work by themselves without the addition of the original 1gb module?

Indeed yes. That was my first test when the 4 + 4 did not work. I tested each one by itself, in each slot. 4 + 0 worked every time, either module in either slot. And so does 4 + 1, in either slot.

If you used Crucial's memory advisor and chose your MacBook you'll get exactly what you need. You won't be disappointed.

I'm surprised by that. Apparently the system can force one module to run at the proper speed but not both. You should return the ram and get ram that works. Your MacBook WILL run 8gb but it's got to be the right ram.

That's not a single 8gb module is it? You don't want that, you want 4gb x 2

That looks good to me.