I wanna overclock my pc

my spec is as below:-
AMD Athlon 64 2800 1.8ghz
DDR 400 1gb ram


i lower my ram ddr400 to ddr200, lower ht x4 to ht x3, but increase fsb from default 200 to 300 (multipier using defaut x9)

at stock i have a 1.8ghz, but now i have a 2.7ghz, i gain 1ghz

i wonder it is a waste or gain? since the DDR400 to DDR200

if benchmark is low then mean i was a waste?

and should i compare it? like i compare the current overclock setting with the stock speed?

then wat kind of benchmark should i do???
mem benchmark is test that the memory can run stable or not, is it?
superpi to test the overall performance fast or not, is it?
3d mark? i think is test for the graphic card performance? is it?

i found it it was a gain, but not a big gain, just a small gain even i have a higher FSB and higher ghz, but the Ram is affect the rest too, if compare to DDR333, benchmark is higher eventhrough i have a lower FSB and lower ghz