you seem pretty ignorant about pocessors. do you do any research before you buy your electronics at all? i would highly recommend organizing your needs, then read reviews. do a little reshearch before purchasing your next motherboad and processor.
i'm truly amazed that you could have assembeled this system correctly on what little information you seem to have.
anyhow, the 1.9gh processor you bought is plenty powerful.
if you have heavy 3d graphic needs (ie. gaming, expecially shooters) than i would recommend that you purchase a powerful graphics card as well, a gforce4 ti4200 would be a good budget choice.
anyhow, your processor will perform about equal or better (thus the 1900+) than a pentium 4 1900mhz processor. since intel sells the vast majority of processors (over 80% i believe) their pentium 4 is the standard by which everthing else is measured, expecially for the novice such as yourself.
megahertz is somewhat irrelevant in todays processors and other factors are becoming more relevant as processors increase in speed. try thinking of a processor as a big math calculator. the intel calculator can do 1 problem (calculation) per megahertz (speed). the AMD processor can calculate 1.5 or 1 1/2 problems per megahertz. thus calculation x speed = actual performance
it gets even more complicated. other factors have to be include also, so this math is not very exact. factors such as fontside bus speed, memory speeds and latency issues, chipset performance, casche size..... you can get the picture.
the best way to test overall performance is to judge with benchmarks.... take several programs (popular ones)from different groups (ie. 3d, audio, video, word processing, several from each group). then see how fast the processor runs them, the benchmarks will produce a score(number) based on performance. then average those (number) benchmarks together and get a (mean) or average performance of them all.
this is why i say do your research, becase if you know what benchmarks are most important to you (applications your will run most frequent), you can help to configure your system to perform best in those areas.
chances are, if you got an athlon, you will be ok. they tend to have good performance in a wider spectrum of programs. intel generally has 1 or 2 types of programs that run exceptionally fast on thier systems......
hope this clears things up a little...
athlon1gh@1.4gh avia
asus a7v133 w/raid
gforce3 ti 500@255core/570memory