What kernel settings are recommended for an interactive and responsive desktop on a 6 core system with 8Gigs of RAM? I've set swappiness to 10 as recommended in a few guides but what other setting can be tweaked? Are there any tweaks for the CPU?
Your question is broad and the answer could vary from a short set of tips to a dissertation on the Linux kernel =)
Generally speaking, the default configuration is going to do well. From there you sort of need to start to break it down a bit more and start to get specific, specific to your hardware and what you want to optimize.
You can make some adjustments using sysctl
You will find many blogs / posts on suggested settings, such as
A google search will turn up additional tips, both for security and performance.
BUT they are often somewhat short on details. For a more in depth understanding of what and why you are making kernel settings you need to start reading the kernel documentation.
From there , you start building and benchmarking custom kernels.
You can read the documentation here
In my experience, the default configuration of your Ubuntu kernel is likely to be sufficient and if you want to improve your performance you are going to need to do a bit of reading and to some extent experimentation with your hardware.
You can also get significant performance boots from using or tuning your video card, hard drive, wireless, etc as outlined in the links below.
Third party, Custom kernels
There are also custom kernels, some for power management, some for performance. The Liquorix kernel is popular
It is the Zen kernel packaged for Debian (Ubuntu) systems.
The Liquirix / Zen kernel is a patch + some customizations in the kernel configuration.
You can review the configuration here
And compare it to your customizations or the Ubuntu kernel here
This information should get you started, and you can read as much or as little as you like. If you have a more specific question ...