Does modifying read cache on my SD card also affect the speed of reading my Ext3 partition? I'm trying to make Link2SD work on my phone so I partitioned my 16gb SD to 4gb for the Ext3 partition and the rest for normal storage.

I'm noticing some slight lag on my usage of the phone and I read on this article that I can in fact, increase the read cache to speed up reading contents on the SD. My question is; does increasing the read cache also affect the speed of reading my Ext3 partition? Or does it only affect the "normal" storage?
As with normal disks, this should apply to the disk and not a specific partition. Some file systems offer additional caching, which then would apply to the specific partition -- but disk cache should always apply to the entire disk.