iMac 2011 Memory Upgrade Slower Benchmark

Hey Guys!

Just upgraded my baseline 2011 21.5 from 4GB of RAM to 8GB of Ram for £20 through crucial.

After installing the ram decided to run some benchmarks on geekbench the result was a lower score than previously taken, the processor scored higher than before however the memory scored much lower. I then booted up Windows 7 via bootcamp to see if there was any difference in the windows index score and again it decreased by 0.3 on both CPU and RAM. Why is this?

My slots are currently:

Slot 1 - 2GB (Apple)
Slot 2- 2GB (Apple)
Slot 3 - 4GB (Crucial)
Slot 4 - None

Help would be much appreciated

nOw2 said:

The memory system is dual channel which requires matched pairs, as per the original Apple DIMMs. Installing an unmatched pair drops the access to single channel model which will affect memory access speed.

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Ahhh right i thought this may be the case, so would i need to buy another 4GB stick in order to get true 8GB of memory at the right speed? and if so would i get the correct dual speed by keeping both 2GB sticks and two 4GB sticks in the system, giving me 12GB?

aliensporebomb said:

Yes that would work and correct the dual channel issue.

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That's great, Cheers for your help guys