I expected a little bit slower performance since the British GDP and market is considerably bigger than in the 1.7.0 save, but it looks pretty similar. A couple seconds slower in 1900, 2 seconds faster in 1840. I also wanted to test the impact of trade a bit, so the third test is with me adding some extra trade routes (going to the trade tab, seeing what the game recommends that I import/export, and set up trade routes that it thinks would grow larger than size 1, so I was being pretty lazy), and the fourth test is with isolationism enabled. Isolationism was marginally faster (AI Britain only has a small handful of trade routes), adding extra trade routes had a noticeable impact.
GPU: GTX 1080
CPU: i7-6700K CPU @ 4.00GHz
RAM: 16GB (2x8) 2133MHz DDR4
SSD: Yes
1840 time: 2 minutes 27 seconds
1840 Slow Tick Operations:
GPU: GTX 1080
CPU: i7-6700K CPU @ 4.00GHz
RAM: 16GB (2x8) 2133MHz DDR4
SSD: Yes
1900 time: 5 minutes 9 seconds
1900 Slow Tick Operations:
1900 with extra trade routes
GPU: GTX 1080
CPU: i7-6700K CPU @ 4.00GHz
RAM: 16GB (2x8) 2133MHz DDR4
SSD: Yes
1900 time: 6 minutes 23 seconds
1900 Slow Tick Operations:
1900 with isolationism
GPU: GTX 1080
CPU: i7-6700K CPU @ 4.00GHz
RAM: 16GB (2x8) 2133MHz DDR4
SSD: Yes
1900 time: 5 minutes 7 seconds
1900 Slow Tick Operations: