Silk uses the Amazon Cloud to speed up web page loading. If you’re concerned with privacry, you might want to disable some of these features. All of them can be changed in your Silk Browser’s settings in the Cloud Features menu.
Cloud Features: Enabling this will allow Silk to use the Amazon Cloud to load web pages faster. It does this by storing some of your browsing data on the cloud. Disabling this will turn off all the cloud related features. By default, this is enabled.
Optional Encryption: Silk routinely makes from the cloud. Enabling this will encrypt web pages through Silk’s servers. As a result, it might slow down page loads. By default, this is disabled.
Instant Page Load: Silk will attempt to load the next page you are most likely to visit, resulting in a quicker page load experience. By default, this is enabled.
ESV Prompt: Silk notifies you when a web site is compatible with the experimental streaming viewer (ESV) allowing you to view some Adobe Flash videos. By default, this is enabled.
I use the default settings when I’m at home. While travelling, I turn off the feature. I don’t notice a big difference in terms of page loading speed. That said, I don’t do a lot of web browsing on my Kindle so your mileage might vary.