Now this isn't a direct fight where we see is which would beat the other directly.
This is an overall power gauge of the two.
Now we know Silver Surfer doesn't hit as hard as non-holding back Superman. (Yes even an amped Silver Surfer would still be weaker than Superman)
We also know that Superman can not create a blast as strong as non-holding back Silver Surfer. (Yes HV isn't as good as the Power Cosmic)
So the question becomes which one possess the most damage output.
Parameters
A) They are bloodlusted
B) They are putting everything they have into this particular attack.
C) And for circumstances sake we will ignore things like energy vs blunt resistance. These attacks will be considered the same attack for this scenario.
So in this which one possess the most damage output.
I would say a Surfer blast, Supes back up his punch with momentum, speed and the fact that is harder to keep at bay a charging opponent, he is a very effective fighter but it doesn't come just from sheer strenght. I mean, Superman cannot really charge his punches and Surfer can charge his beams.
I believe an all out blast from Silver Surfer would probably have a higher damage output than an all out/not holding back punch from Superman. However, that statement is considering the fact that energy projection is probably more potent than pure physical force. Therefore, if what you mean by "these attacks are the same" is we can channel the force of Supermans punch into pure energy, and measure who actually produces more power then i might be inclined to say Superman. Ultimately, im undecided, and will leave it up to the greater minds to figure this one out.
I'd say Surfer's blast, actually. Superman's punches are very powerful, but the properties behind a blast from Surfer exceed a punch. The punch is simply one extremely strong impact on one point of a surface. The blast contains near equal concussive force as the punch, as well as heat, radiation, and whatever other properties Surfer wishes to channel into it, and it will also engulf the target's entirety and strike at all points on the surface, or Surfer can fine tune the blast to be surgical and strike a particular point. Surfer can also custom make his blasts tailored for any target to bypass it's defenses, or simply disintegrate matter.