First, it is useless to store data in memory if you want them be committed into disk storage. The general idea here isn't about switching to some new version of mysql or SSD disks, it is about to realize that you have a data-flow inadequate for your one-server architecture.
Second - check-point intervals should be adjusted to your actual data-flow, which means they should be executed often enough. If there is situation of almost constant checkpoint - non-stop data writes, that is the sign that you need to consider sharding/multi-server solution.
The hints that there must be no other disk activity on the same hardware volume or any swapping in OS, I suppose, are obvious. People who have a /var/log and /var/db on the same volume are idiots.
There are also good idea to use one file per table storage and put a data and physical logs on a separate hardware volumes (links are your friends). One raid-X volume that fits all is a quite naive solution. Raid isn't a guaranty of reliability. Replications to a back-up servers are.
Third, when you test your configuration before put it into production, you should tune-up your servers to perform with data and log syncing, and then figure out appropriate buffer sizes and checkpoint intervals. Then, in production, when you're experiencing an increasing flow of queries, you may choice to switch into different syncing strategy and/or more often but a little bit faster checkpoints.
Configuring mysql with huge buffers and no sync means lack of understanding the basic concepts, self-delusion and misuse of software and hardware. ^_^