My Nokia Blog has done some real browser tests between an iPhone 4S running iOS 5, iPhone 4 running iOS 4.3 and a Nokia Lumia 800 winning Windows Phone 7.

Long story short is that the iPhone 4S dominates.

Check out the results below as well as the video comparing the three side by side.

Complete scores:

iPhone 4 – iOS 4.3
Nokia Lumia 800 – WP 7.5 (aka Mango)
iPhone 4S – iOS 5

Browsermark Test: Higher is better
iPhone 4 (iOS 4.3) – 37 503
Nokia Lumia 800 (WP7.5 aka Mango) – 30 452
iPhone 4S (iOS 5) – 86 702

Speed Reading Test:
iPhone 4 (iOS 4.3) – 2 fps (iPhone 4 with iOS 5.0 – around 37 fps)
Nokia Lumia 800 (WP7.5 aka Mango) – 40 fps
iPhone 4S (iOS 5) – 60 fps

Sunspider Test: Lower is better
iPhone 4 (iOS 4.3) – 4018.2 ms
Nokia Lumia 800 (WP7.5 aka Mango) – 7188.7 ms
iPhone 4S (iOS 5) – 2266 ms

Acid3 Test:
iPhone 4 (iOS 4.3) – 100/100
Nokia Lumia 800 (WP7.5 aka Mango) – 100/100
iPhone 4S (iOS 5) – 100/100

HTML5 Test:
iPhone 4 (iOS 4.3) – 210
Nokia Lumia 800 (WP7.5 aka Mango) – 141
iPhone 4S (iOS 5) – 296