OptiFine was released differently back then. It consisted of four editions.
If you're confused on which one to use, read further.
The standard edition. There's usually no reason to install this specific edition, unless all you care about is the base OptiFine functionality, that being some extra options and texturepack features.
It does provide optimizations, but there are other editions that are straight up upgrades in this matter.
The smooth edition. Expands upon the standard edition.
Makes the chunk updates distributed better over ticks, removing lag spikes.
This edition is a good balance between performance and stability, as it's better than HD G but also lacks the issues of HD MT G2
The multicore edition. Expands upon the standard edition.
Makes the chunk updates run off-thread, removing lag spikes and greatly improving performance, sometimes doubling FPS in areas that are constantly being updated.
However, has issues on some hardware configurations. If you notice frequent chunk flickering, it's probably a good idea to switch to HD S G.
The antialiasing edition. Expands upon the standard edition.
Adds the anisotropic filtering and antialiasing options, making the game look way nicer and smoother.
However, lacks the optimizations from other editions.
A good choice if you care about visuals more than optimizations.
All Minecraft Beta 1.7.3 OptiFine editions suffer on long distances (noticeable even 10000 blocks away from spawn).
However, there are community-made patches for this issue.