Samsung 840 Pro SSD Temperature too high?

Hi guys so I got 3 SSDs on my Laptop (Clevo W370ET) 1 of them is a Samsung 840 Pro (256) which is the one I use for windows 8.1, the other 2 are for Steam and Data.. so I notices that since day 1 the Samsung SSD temperature rises to 45C, is this a normal operating temperature?, my other 2 never go above 30C, even when I used to use them as the main OS.. so is this temp normal?

Thanks

PS, I have tried re-arranging the Drives around the laptop but the temperature has not changed.. also I notices that the Samsung is the only one which seem to be encased in some kind of Metal alloyed? (aluminium perhaps?) the other 2 are plastic and am wondering if this is what is helping the SSD to get hot?

Thanks again :D