Amazing you got those gainwards that high! I usually see the Gainwards hitting 240/520 max! From my research, any 4 NS memory modules are good - Etrontech 4.0 NS on gainwards, asus, and leadteks, Hynix 4.0 NS on visionteks, PNY's, possibly MSI's, Creatives, Hercules, and possibly more. The Etrontech ones usually hit 520 to 560, in most cases 530. The Hynix ones usually hit 500 to 580, in most cases 500 and 530. The best oc cards i seen are:
EVGA ti200 E1 ( even though it can't hit 600, it surely hits 520 or 530 at least)
Gainward GF3 ti450 GS (not sure about the non GS)
Visiontek GF3ti200 model 4401
PNY GF3 ti200 latest revision
MSI ti200 (possibly the later revisions)
Hercules ti200
Asus ti200
Inno3d ? Palit Daytona ? Abit ?
Maybe you guys can help me finish this list by posting your results, thus i can get an average oc info on all the ti200s, the ones i need more info on are PNY's, MSI's, Abit's, Inno3d's, PalitDaytona's, Non Golden sample Gainwards, and if any others.
The ones that sucked at OC were:
Early revisions of Visionteks, Gainwards with 4.5 NS, any ti200 card with 5 NS memory Period, and i geuss EVGA if u wanted 600 mhz.