Originally Posted by cadaveca
Desktop chips aren't really built for taking 24/7 high loading, even though many users do so. Xeon chips are, adn hence are typically higher-quality wafers. I understand why there is a pricing difference, but at time it does seem that those pricing gaps between the two are rather high.
I don't know about the quality of the silicon itself (The Xeons do run at lower voltage) and how long it takes to degrade but by the time you degrade a desktop chip it will be really old and slow (would you use a Core 2 Duo for rendering or a quad IB).
The problem I see is the VRM (it needs to be made from quality components and very well cooled).
As long as you keep the CPU cool you won't see any major problems.
However, some people render with highly overclocked CPU's which IMO is a big no no (stability is a serious issue and VRM strain is huge). You can forget about using prime for stability, it's a kids game compared to long term heavy load.