Cluster (allocation Unit) Size For NTFS In Windows 7?

I am using Win 7 Pro x32 and have partitioned my hard drive into two NTFS partitions. One is for my Windows other one is for my files and personal documents.I'd like to know how to format the partitions in terms of cluster size. I read a lot of articles which didn't actually answer my question - what are the differences between formatting with a big and small cluster size, and how does all that influence the overall performance. I should also mention that I am willing to sacrifice some bits and bytes from my partitions, if needed, as long as I could somehow increase performance. Also, I noticed that the standard Windows 7's formatting dialogue allows to format a partition only with a limited size of clusters compared to trying to format a partition using software such as Acronis Disk Director or Paragon Hard Disk Manager where I was able to format with a much greater cluster size. What to do, what to do...? You could save the small talk such as - 'small cluster size wastes less disk space but works slower, and vice versa, greater cluster size wastes more space but gives better performance'.