are portable programs faster than installed programs?

There is nothing about the software itself that would make it faster (but if it has been hacked to be portable then the hacks may have made it faster or slower as a side effect … although almost certainly not in a noticeable way).

Running the software from a different drive might make a difference (e.g. a good USB memory stick will have faster access times then many hard disks) and you might be doing this as another side effect of using a portable edition. Any speed enhancements (or penalties, you might have a fast HDD and a slow memory stick too) will occur mostly while the application is starting (after which it will be loaded in memory and not need to access the drive often).

The short answer to that is no they're not.

An installed program on a drive will have faster access to the internal hardware.

Portable, I assume you mean running one through a USB port either

from a flash drive or external drive.

Even the fastest USB port would be slower than a hard drive's access.

This depends on alot of factors like..

1) Where it's ran from (if its on the hard drive it will run faster than a usb)

2) If the portable app needs to be extracted then that takes longer.

3) if the app is extracted on the HDD.. it should run as fast as installed apps.

As in running a program through a Flash Drive?

If so, no. Your computer needs to read through to the Flash Drive which may not send data to the processor as fast as a normal hard drive. Installing the program directly to the computer's hard drive, then running it would be much faster.