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Off topic: Using `background-attachment: fixed` for your background image will cause high CPU usage as the user scrolls.

http://fourkitchens.com/blog/article/fix-scrolling-performan...

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Nah, modern browsers simply offload this to your GPU. They send the background layer to the GPU once, update the foreground as you scroll, and let the GPU composite them for display. Since this is a screen-space effect, and the fill-rate of a modern GPU is immense, this is pretty cheap overall.

Well a lot of people use Chrome and I immediately noticed a problem with the site when using Chrome, so maybe it's still something to keep in mind until it's improved.

That talks about Chrome, which is known to use a lot of resources in general (see: battery life tests).

Is it also an issue on IE/Edge or Firefox? What about Safari/Mobile Safari?

This line from the article makes me think it affects Mobile Safari (or did in the past).

> The performance for this feature is so bad that iOS simply ignores this property.

Oh, I guess that's why it seemed perfectly smooth on my iPad. Thanks.

position: fixed wasn't supported until iOS 5 and not completely/well until iOS 8: http://caniuse.com/#feat=css-fixed

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