gh_discussions/Query/3598.md

# Detailed routing time for mock-array as a function of area

Tool: Detailed Routing

Subcategory: Performance analysis

## Conversation

### oharboe
Using https://github.com/The-OpenROAD-Project/OpenROAD-flow-scripts/pull/1211 and https://github.com/The-OpenROAD-Project/OpenROAD-flow-scripts/pull/1212, I've plotted detailed routing times for the same Verilog 8x8 8 bit datapath mock-array, changing only the size of the element macros.

Any thoughts on these running times for the mock-array for detailed routing? Expected? Unexpected?

The algorithm seems to be MUCH faster for smaller areas

![image](https://github.com/The-OpenROAD-Project/OpenROAD/assets/2798822/c2e92b32-302f-4ac5-9381-1178c6520b76)


Biggest array:

![image](https://github.com/The-OpenROAD-Project/OpenROAD/assets/2798822/a7ca8cb1-030d-488a-99c7-c80809e46529)

The element-element wires are not straight, lots of little deviations from horizontal/vertical:

![image](https://github.com/The-OpenROAD-Project/OpenROAD/assets/2798822/67bb32ef-cd99-4369-bd27-becaabd73e8d)

Smallest array:

![image](https://github.com/The-OpenROAD-Project/OpenROAD/assets/2798822/8b5ce6e6-c647-4623-9fa9-26420ec0d7a8)


"All" element to element wires are horizontal/vertical (didn't check exhaustively):

![image](https://github.com/The-OpenROAD-Project/OpenROAD/assets/2798822/4e3f7f0e-ae10-451e-bb61-a012a48c28bd)



### maliberty
How do the number of routing iterations and iter0 DRCs compare between datapoints? 

### oharboe
I wasn't able to follow up on this in a timely manner.