It is all in the title. While Flash and Cyborg have science pedigrees, I am just comparing Clark and Bruce.
Generally speaking Batman.
There are some stories where Superman is a genius and has some pretty impressive feats, or just super advanced Kryptonian tech at his disposal.
But on average Batman is generally the smarter of the two, especially when they appear together.
Superman, in terms of capabilities relating to the hard sciences. He generally possesses or creates superior technology, understands scientific principles and hypotheses better than most experts in the related fields, and has made some genuinely wacky stuff like machines that make alternate dimensions and whatnot. Batman's niche is more in the fields of strategic/tactical thinking and analytical ability. I don't remember who, but someone on this site said Superman is smarter than Batman in the way that an advanced supercomputer is smarter than the world's smartest man. If you need to build a rocket to fly to the end of the universe, Superman will come up with a design in a few minutes (and then probably build it for you as well); if you need someone to toss around war strategies and analyze a foe's behavioral patterns to predict their next plan of action, you're better off asking Batman. It's why Batman is usually portrayed as smarter when they're together in books like Superman/Batman or JLA; Batman's knowledge is best suited for in-the-moment conflict scenarios (which comprise about 95% of all superhero adventures); Superman's knowledge, not so much.
Barry Allen doesn't have much of a science pedigree to speak of, at least not compared to Superman or Batman or the Atom or Steel or whomever. Batman's forensic skills are substantially better. He's an expert on the Speed Force for obvious reasons, and his experience with that occasionally lends itself to scientific capabilities in the fields of dynamics and kinematics, but not very often. I don't know why Cyborg is even being mentioned here, but ok.....
I don't know why Cyborg is even being mentioned here, but ok.....
I'm assuming you're being rhetorical but likely because he is equating Cyborg's ability to rabidly gain information from machines as an indication of intelligence and/or his ability to manipulate machines as some indication of actually understanding their inner mechanisms...
Putting aside PIS or WIS, Superman should be smarter. Kryptonians have a far more advanced society than humans and Clark has access to their technology, which he studies along with various other alien disciplines. In addition, Clark learns faster and has built insanely complicated and advanced devices, while Bruce has not. And Clark keeps up with human scientific developments which keeps him ahead of the curb.
But to make Batman a good partner, writers feel like they need to knock Clark's IQ down a few pegs. Bruce is really just a better detective. Clark is the better scientist.
In the beginning of the video below, Clark, Barry, and Victor display a strong knowledge of inter-dimensional travel that Bruce has not, or else he would be a more effective hero--for example, using advanced tech to banishing enemies like Superman and Flash do. He can't even give himself powers like Clark has demonstrated above with his super charger.
As it was said Superman is smarter than Batman in terms of scientific stuff while Batman is more of a strategist and his knowledge in that area is stunning.While Superman can create machines and technologies that he only and a few smart men understand.