I have DDR533 by GEIL, 2x512 MB dual channel, "ultra platinum."
1. Awesome memory, I am running it at 269x2 = 538 MHz at 2.5-4-4-8, 2.85V, passing 10 rounds of MemTest and 2 hours of Prime95 (that is my methodology and I am not interested in debating it).
2. It gets very hot, I am using active cooling.
3. The scores are the best I got with any memory ever, talking about Sandra, Aida, PCMark.