My AMD blows my Pentium away in these areas: compilation of C++ file which go overboard with templates, scripting languages (perl, python, php), exotic compiled languages (Common Lisp). The mysql benchmark suite also shows a huge advantage but I am not sure this benchmark suite is reliable and that I ran it correctly.
The Pentium is competitive when compiling C and moderate C++ files and for video and audio encoding.
Both judgements are adjusted for CPU price, that means "faster for the money" or "competitive for the money" for my CPUs (see sig).
Hyperthreading is mostly a joke when it comes to just run CPU-intensive things at the same time, and at work I had to turn it off because it lead to a huge slowdown.
However, Hypterthreading is a huge advantage if you mix one CPU eater in the background with a game in the foreground. I suspect this is because the hyperthreaded CPU can initiate bus transfers in situations where the normal CPU is blocked. The effect is the same under Windows and Linux so I think you can mostly rule out scheduler oddities, this is something hardware-wise. I suspect but did not verify that this applies to other heavy graphical applications on the AGP bus (GIMP/photoshop, Mozilla) as well.
Having said all that, I still like my Intel box better. I will get some extreme edition CPU for it and it will serve me long and well and as main allround machine, while the AMD is reserved to single things like blowing up tanks or experimenting with 64 bit OSes.