Automapper running extremely slow on mapping 1400 records

Question

I am using AUtomapper which I am very impressed with however, I have a complex object with many nested collections. I\'m using Telerik OpenAccess and it returns the 1400 records

Answer 1

There was a team at my previous job who were also using Automapper but in the end they removed it because of the performance impact.

I think in this specific scenario it's best to write the mapping code yourself, or start replacing them one by one. Maybe one mapping is causing the bad performance?

Answer 2

I benchmarked automapper. A single core of a 2.0GHz Xeon is able to handle 85,000 maps per second, on a small object (3 properties). It was 60 times slower than manually copying the properties. If you'd like, I can benchmark other values for you.

Answer 3

For those coming to this later, AutoMapper 5.x release made significant performance improvements, where mapping speed is only slightly slower than hand mapping (1M items):

• Native: 0.19s
• AutoMapper: 0.49s
• AutoMapper 4.2.1: 29s

Answer 4

I don't think tools like this are designed for mapping so many records. I think AutoMapper is designed for mapping a View Model and it is not normal to display 1400 records on the screen.