I set up Magento CE 1.9 on Synology DS 1515+(DSM version: 5.2).
There are two websites, one of which has 364 products, the other has none.
Recently, when I add a product to cart as a registered customer, it takes more than two minutes to respond.
If I add a product to cart as a visitor, it responds fast.
I've enlarged memories of PHP runtime and Mariadb, but there is no improvement.
Does it need to adjust any other places to improve performance?
There are many items to calculate total amounts when add cart and checkout.
What takes most time is Mage_Sales_Model_Quote_Address_Total_Shipping.
I enter into Admin>System>Configuration>Sales>Shipping Methods, and disable those not required, for example, UPS, FedEx.