By "high performance" I think he meant they run at a high frequency, which, in addition to high voltages is the cause of heat production. As far as not needing active cooling... every bit of airflow helps, especially when it comes to overclocking. It certainly doesn't hurt to have fewer dead spots where stagnant air can accumulate, one of which being near the ram. As long as you don't go deaf because of all the fans, I wouldn't advise against it. However, the thread starter's DDR400 memory shouldn't be running at temps typically associated with DDR2 or even RDRAM, for that matter.