Subj : Re: Pi-FAN for RPi4 with 4 (instead of 3) cables? To : The Natural Philosopher From : Michael Schwingen Date : Mon Dec 09 2024 13:47:52 On 2024-12-09, The Natural Philosopher wrote: >> I was surprised you'd use MTBF for a component which is expected to >> steadily deteriorate due to wear and tear. >> >> I though MTBF was more a random failure thing. >> > No it isnt that at all. MTBF is a measure for the rate of failures *during normal lifetime* - ie. 1 / failure rate It is *not* the lifetime of a component. MTBF is a measure for failures during the flat part of the bathtub curve. Failures due to end of lifetime (like normal, not-premature wearout on a fan) are not part of MTBF. https://www.vitecpower.com/technische-daten/the-difference-between-mtbf-and-lifetime/ https://www.rs-online.com/designspark/why-l10-life-expectancy-is-key-for-fan-durability-over-mtbf-ratings https://www.digi.com/support/knowledge-base/understanding-mtbf-mean-time-between-failures cu Michael -- Some people have no respect of age unless it is bottled. --- SoupGate-Win32 v1.05 * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3) .