I have seen the DDR3 with varying numbers. Like 10200 or similar, 12800, etc.
On my box I seem to have 100% CPU usage regularly.
I did notice that for the past few months my update notifier keeps saying do not upgrade.
I'm not sure why.
Shut down update-notifier, then upgrade with Synaptic. It will point out any problems to be corrected. Once that's done and the upgrade has finished, close Synaptic and restart update-notifier. It should then continue to work as expected.
I like PCLOS but have been thinking about going to Mint because of all the extra software available.
PCLOS is still 32 bit too. Mint you can get either way.
We will too, very shortly. The main hold up, at this point, is the new graphics theme being made for the official 64 bit release. I'm running it right now, and have been doing so for months. It is very stable and user friendly, just needs the final polish to make it pretty.

If I have a CPU with multiple cores I expect every one of the cores to share equally in the load, not max out one then go onto the next. That would be pointless.
If I run any VM I will have XP on it since the memory will exceed the 4gb limit for XP.
I would also set up my two SSD drives in a RAID 1 via on board hardware settings so as not to have linux do it. I don't want to have to configure anything. Just plug and play.
I am hoping that the new generation of SSD's have on board TRIM support. Maybe buy one of those.
I pretty much want double my existing speed. At least the computer would be good for a few years yet.
I expect this build of my machine to last quite some time too. I may, at some point, replace the four core with a six or eight core, and maybe add an SSD or two, but otherwise it's pretty much set for the long haul. I put it in a new case because the old one was 12 years old, and lacked front USB, eSATA and audio jacks. I was looking for an add in panel, and found what I wanted for $29.99. Then I saw this case, on the same web page, with the same front ports included, with the drive bays facing the left side, and all the drive and external bays requiring no tools to mount whatever was placed in them. The side panels are held in place with large thumb screws too, so no tools are required to make changes to the hardware, except for fan mounting screws. It came with three 120 mm fans, already mounted, and an option for two extra 120 mm speed controlled left side panel fans for $39.99, on sale. The optional fans were another $7.98 for the pair. It seemed more prudent to buy the case, and extra fans, than spend the $29.99 for just the front port panel.
It really is a nice case, well thought out, well built, and the 120 mm fans are very quiet, as in, I have to place my hand in front of them to be sure they are running. I don't hear them at all. The front fan and the two side panel fans blow inward, while the top and back fans exhaust, giving excellent cooling to the interior and all components. One of the drive bays has a special carrier for up to two SSDs, and extra ones can be ordered, if desired. The bay itself can be used for either a standard hard drive, or the SSD carrier, and the carrier will work with any one of the internal bays. The power supply is bottom mounted also, so that big heavy power cord is on the floor, not in the way of everything else connected at the rear.