Goldeneye 007 has the highest processor requirements of Nintendo 64 games, thus I can't help you much.
First off, Azimer's audio plugins have been known to cause repeated game jerkiness and stuttering. Goldeneye 007 probably is going to be unplayably slow with Azimer's audio plugin, at least with the earlier versions.
Also, if you want to enjoy Goldeneye 007, you're going to want to raise the processor clock speed. Seeing that it's underclocked.
Your processor, if it's an Athlon XP 1500+, it's made to do at least 1.3 ghz!
Otherwise, the lowest Athlon XP that I heard of is an Athlon XP 1400+, which is at least 1.2 ghz.
Then if you upgrade your processor, an Athlon XP 3200+ or higher is recommended.