Originally Posted by sunburn39
I've always questioned factoring in MTBF into the mix. Do people experience sleeve bearing fans failing at a high rate?
Definitely another aspect of a fan to consider, but I don't think it should carry equal weight. Most fans have a few years MTBF. I honestly can't see myself keeping a fan for 10 years or complaining that it failed after 3. Curious to know if people are having bad experiences with 30,000 hour fans, thus switching to 150,000 hour fans.
I've noticed (especially on hot things like heatsinks) that the motor on a sleeve bearing fan tends to seize up a lot quicker than most other types of bearings. MTBF is also just an indicator of the mean time, not guaranteed lifetime. Remember, on a 30,000 hour fan, half of them likely failed before 30,000 hours (of course, half of them lasted longer).
For case fans, I'd say it's not a big deal. They usually won't be running in an environment hotter than 35-40c at the most, and if they fail, nothing is in serious danger of immediate failure. For a heatsink fan however, I'd definitely prefer to spend a little extra for peace-of-mind. It's just like how most of us buy high-quality power supplies - even if the difference in failures is numerically not that big, thinking about it as being three times less likely to fail is definitely worth a bit extra.