The first one: [EDIT: Found it! Thanks to RolfAndreassen]
This is turning out to be *really* hard to find; I would have made a point of saving it if I'd expected no-one else to have heard of it. I need to make a page of all the weird singularity/transhuman fiction I've read. -_-
Anyways, what I can remember:
I think I read this on the web. I *think* it was a short story; at most novelette length. This was within the last 5 years or so.
Basically, it's the future, humans have done lots and lots of intelligence enhancement; each generation is smarter than the one before. Then we find a planet with alien ruins. There is a ship sent there. For reasons I can no longer remember, one of the people (female?) on the ship tries to destroy the ruins, and another tries to stop her (pretty sure male). The destroyer is younger, and hence smarter, than the protector, so he ends up taking lots of heavy-side-effect nootropics to keep up with her. The war is fought almost entirely by 3-D printed robots from the ships machine shops.
The emphasis is very much on intelligence: that a standard deviation of IQ is going to determine the results of any strategy game (probably mostly true, given equal experience) and that war is basically that (also mostly true in this case, since the robots won't freak out and run).
I particularily remember a scene in which the main character takes a drug that will up his IQ by 20 points or so for a while, at the expense of 12+ hours of very bad (insanity? unconsciousness? can't remember). Also waves of (remote control?) robots fighting on the surface of the planet below.
The second one: [EDIT: Found! Thanks to nazgulnarsil]
Humans develop AIs, which are fully benevolent and try to help/protect humanity. There end up being problems with the sun, and they try to fix it but create a horrible ice age, and eventually they just upload everybody and go looking for something better. They decide that stars are true problematic, and park humanity around an interstellar brown dwarf.
One particular AI ship is somewhat eccentric and thinks that protecting humans isn't everything. A group of humans convince him to take them (or rather, their descendants) to earth. To prove they are capable of the (extremely long) journey, the ship requires that they live on him, without going anywhere, in a functional society for a thousand years. Then he takes them to earth.
FWIW, I'm trying to make a page of all the singularity/transhuman stuff I've read; it's at http://teddyb.org/robin/tiki-index.php?page=Post-Singularity+And+Transhumanist+Fiction+I%27ve+Enjoyed&no_bl=y (just started).