Here are Bootchart
results indicating the boot speed from the Linux 3.0 kernel
through the latest Linux 3.6
These concise Bootchart results are from an AMD FX-8150 Bulldozer
system with 8GB of RAM and an OCZ SSD. I'm in the process of running a number of new AMD Bulldozer Linux tests for publishing in future articles and along the way Bootchart was installed for one of the comparisons.
The Bootchart results in this article for the latest-generation AMD Bulldozer come after using each of the main Ubuntu Linux mainline "vanilla" kernels and allowing the kernel to boot twice and then archiving the Bootchart-produced graph. Ubuntu 12.10 from 12 September was used as the base operating system with the vanilla Linux kernel Debian packages. The Bootchart package used was what's available from the Ubuntu Quantal repository.
Beginning with the Linux 3.0 kernel from July of 2011 for this Bulldozer eight-core system, it booted in 16.61 seconds with a peak disk throughput of 232 MB/s. With the Linux 3.1 kernel the boot time increased; Bootchart measured a time of 24.19 seconds while the peak disk throughput was slightly higher at 236 MB/s. In the Linux 3.2 kernel the boot performance improved with the time dropping down to 15.55 seconds and a maximum disk throughput of 246 MB/s. Strangely, for the Linux 3.3 kernel, the recorded boot time was 48.56 seconds with a peak disk throughput of 246 MB/s for the OCZ solid-state drive.
When on the Linux 3.4 kernel the boot time was at 11.40 seconds with a maximum disk throughput of 256MB/s. Then onto the Linux 3.5 kernel, which is similar to what will be found in Ubuntu 12.10, the boot time fell back to 17.78 seconds while the peak disk throughput was at 251MB/s. Lastly, when using the Linux 3.6 daily kernel from this morning (14 September), the boot time recorded was 16.56 seconds with a maximum disk throughput of 252MB/s.
The peak disk throughput has levelled out mostly for this high-end AMD desktop system backed by a solid-state drive, but the boot times were rather sporadic with no clear trend across the past seven Linux kernel versions. Well, that's the case for this particular Bulldozer system at least, results for more Linux systems with different hardware configurations are on the way. The best kernel for boot performance witnessed from the AMD FX-8150
Bulldozer was 11 seconds on the Linux 3.4 kernel.