I'm just "having fun" to use ado.net entity framework. I did a little test:
to wonder about 16000 times an sql table of fifty records to extract information. Using extension "First" combined with a lambda expression processing time is about 4 times that of lead in the local store (in a dataset) and interrogate him. I also tried to compile the linq query but I saved a few seconds.
It should then, for operations like the one above, where the stock is the subject of the selection remains unchanged during processing, working again with the dataset or entity framework offers alternative but maybe I have not yet discovered?