about:home with its noisy background image combined with a gradient, and its big logo implemented as a background image is quite slow on my Retina MBP. Switching to and closing an about:home tab has a noticeable delay. Opening a new about:home tab by middle-clicking the home button has a janky tabopen animation. All these symptoms are not present on my other machines with lower resolutions and less power. CC'ing roc to see if there's anything we can do about this.

about:home is much more responsive when removing the noisy background image and using an <img> element for the logo. This is certainly something we can do if fixing this in the core is not feasible in the short term.

It would be good to see a profile of this. My guess is that the time will show up in our good friend CreateSamplingRestrictedDrawable.

Here's a profile of switching a few times between about:blank and about:home, starting from about:blank. http://people.mozilla.com/~bgirard/cleopatra/#report=64a343cad3cad36e8fb8adadf2744e6ab8003c9f

I was expecting so, but apparently not. Maybe because the image is only 48x48. The profile shows a lot of time in CGContextDrawLinearGradient and even more time in CGContextDrawImage.