Hey there, sigm4!
@GhislainG is totally right! So I'd recommend you to try copying some large files as well just for the sake of troubleshooting and see how the speed will be then. If you have any concerns regarding the SSD, you should follow the link to this thread with some SSD diagnostic tools you can use to test its health: http://www.tomshardware.co.uk/answers/id-1926483/ssd-diagnostic-tools.html
As for the WD Green, I'd suggest you to use WD's Data LifeGuard diagnostics tool to check up on its health and SMART status. Here's a link to the utility: http://products.wdc.com/support/kb.ashx?id=ssdzl0
Though I doubt there's anything wrong with them, it's good to have those drive monitoring software tools.
Hope I was helpful! Keep us posted though!