Ah, didn't even think about iostream taking up time. However, if it is, it's very small, since the results were the same.
@ Jmaster. It's pretty accurate. IE loading in 10 of the same image gives you a factor of 10 greater than a single image +/- a few % because the time for each individual load can vary by a mS or two. While I'm sure that this method is no substitute for an atomic clock it's producing the results one would expect given the symptoms that are occurring. I know I'm really breaking the 16 mS barrier because a file that times in at greater than 16mS can cause me to stutter in my game which is running at 60fps.
@ dario in my test example I load in the same file twice. If there is a difference then it's not very large at this scale. We're talking 25 mS for a small file. Aside from that the goal is to load in a file once without it holding up the main logic loop.
That just seems excessive for such small files, but then again I'm not an expert on such matters. Currently looking into a different, non allegro method to get a comparison.
Update: Enabling openGL and using png's got me down to 9-15mS on the 350x350 and 60~ on the 1100x1100. So a decent improvement there. Reading the 350x350, writing it to an HDC, copying it, and then writing the copy to a bmp file on the HD takes 2mS. A lot faster than I thought. It seems A5 got rid of the ability to load bmps from hdc though =/