I posted a few weeks ago about beachballs etc especially with Safari and iTunes on my 2010 MacBook with 4GB Ram running El Capitan, so I decided to reinstall, I did a clean install of El Capitan, don't get me wrong most of the time it is OK but it is prone to beachballs especially with Safari so I decided to give Bootcamp and W7 a go.
The initial install process was quite slow, slower than a Windows machine but once installed I might be imagining it but I think its faster than OS X, there is no delay in opening programs etc, everything happens in a instant.
Now I am wondering why this would be? I think my 2.4 processor with 4gb or ram just isn't enough for El Capitan.
******
This is only for information for any interested reader trying to install Windows 8.1 or Windows 10 in an "unsupported" (according to Apple) Mac, and not an answer to your question.
I installed Windows 10 in a much older model than your machine, a MacBook 4.1 early 2008 and it runs with all the necessary drivers including WiFi, iSight, sound, etc.

I couldn't do it through BootCamp though...for unknown reasons.

According to Apple that mac model can only reach Lion on the OSX side and Windows 7 through BootCamp.
Since BootCamp refused "to see" both a DVD and a .iso of Windows 7 for reasons I don't understand, I followed a procedure found in YouTube.
It requires to download drivers from Apple, Tuxera NTFS and a free boot tool called reFind.
One partitions the inner drive (assuming one has only one hard drive like in my mac) to make a second partition and formats that second partition with Tuxera NTFS.
With the reFind boot manager installed one can reach the Windows installing DVD and bring it to install Windows in the NTFS partition.
In my case I had a Windows 8.1 DVD.
I used the Apple Windows Drivers plus a Windows tool called Driver Easy to complete those drivers.
Then I updated from 8.1 to Windows 10.
It is very strange and entirely unlogical

that in older (well, relatively old) perfectly working Apple hardware, OSX is much more difficult to bring to a present day system (in many cases impossible) than Microsoft's Windows.
Using MCPF mentioned in other threads in this Forum I succeeded however to update the OSX Lion to Mavericks, also entirely excluded if one only listens to Apple.
It is sad

that Apple itself does not provide ways to bring newer life to good working aged Macs and one must look for third part solutions.

Ed