Hi everyone, I had early 2011 Macbook white 7.1 (the last macbook white apple supplied). It came with 2GB (1GBx2) RAM. I read many articles online and decided to upgrade it to 8GB (4GBx2). What i ordered was 2 RAM 4GB DDR3 1066MHz PC3-8500. After i got those two RAMs, I started replacing them, following trial errors took place: 1) When I replaced both 4GB (i.e. total 8GB) into my mac (removing both the hynix 1GB RAM PC3 8500S), macbook did not boot, it beeped many times and I had to shut it down. 2) When i put only one 4GB (i.e. total 4 GB) into my mac (keeping one channel open), macbook did not boot, it beeped many times and I had to shut it down. 3) Using the same method, i used 4GB in either channels, (only one 4GB RAM in either channels) macbook did not boot, it beeped many times and I had to shut it down. 4) When I put only one 1GB hynix (original) back in only one channel, macbook booted properly, no problem but it was slow. 5) When I put one 4GB (new RAM) and one !GB (hynix) original then computer booted, fast, the sytem shows now 5GB RAM. However, as the memory size in both the channel is different so I think this would affect overall speed. Is it so? Also, I wonder why macbook did not accepted 8GB memory (as internet and many youtube videos mention that it works)? Why single 4GB RAM when inserted keeping one channel open, macbook did not start? I am pretty confused with way macbook kept beeping, and also, regarding acceptance of new RAM, any problem with new RAMs?? Well, this is pretty weird, anyone would like to help me in this regard? I ordered the RAM on ebay, the provider has sent the similar one that of Crucial memory. The details of RAM shows: BANK 0/DIMM0: Size: 1 GB Type: DDR3 Speed: 1067 MHz Status: OK Manufacturer: 0x80AD Part Number: 0x484D54313132533654465238432D47372020 Serial Number: 0x1E1518D8 BANK 1/DIMM0: Size: 4 GB Type: DDR3 Speed: 1067 MHz Status: OK Manufacturer: 0x80CE Part Number: 0x4D34373142353237334348302D4348392020 Serial Number: 0x64133DA7 Should I return those 4GB RAM back and check with other supplier or try the hynix brand or this is usually the same problem??