Performance
With Access all tables involved in a form, report or a query are copied across the network from the server to the client's machine. The tables are then processed and filtered to generate the required recordset. For example if looking up details for one particular order from an orders table containing, say, 50,000 records then the whole table (all 50,000 records) is dragged over the network and then 49,999 of these records are thrown away (this is an over-simplification since indexing can be used to mitigate this to some extent). Contrast this with SQL Server where the filtering takes place on the server (if designed properly) and only 1 record is transmitted over the network.
This can affect performance in two ways. Firstly SQL Server is highly optimised and can usually perform the required filtering much more quickly than the client machine and secondly the amount of data sent across the network link is vastly reduced. For most databases the main performance bottleneck is data transmission over the network hence reducing this can give a really dramatic improvement in performance.
Predicting likely performance improvements is very difficult .
