Joel's widget number 2
On Sep 26, 2010, at 10:47, Chris Adams <cmad...@hiwaay.net> wrote: > Once upon a time, Joel Jaeggli <joe...@bogus.com> said: >> On Sep 26, 2010, at 8:26, Chris Adams <cmad...@hiwaay.net> wrote: >>> There are servers and storage arrays that have a front that is nothing >>> but hot-swap hard drive bays (plugged into backplanes), and they've been >>> doing front-to-back cooling since day one. Maybe the router vendors >>> need to buy a Dell, open the case, and take a look. >> >> The backplane for a sata disk array is 8 wires per drive plus a common power >> bus. > > Server vendors managed cooling just fine for years with 80 pin SCA > connectors. Hard drives are also harder to cool, as they are a solid > block, filling the space, unlike a card of chips. It's the same 80 wires on every single drive in the string. There are fewer conductors embedded in 12 drive sca backplane as there are in a 12 drive sata backplane, in both cases they are generally two layer pcbs. Compared to what 10+ layer pcbs that are a approaching 1/4" thick on the router. Hard drives are 6-12w each, a processor complex that's north of 200w per card is a rather different cooling exercise. > I'm not saying the problems are the same, but I am saying that a > backplane making cooling "hard" is not a good excuse, especially when > the small empty chassis costs $10K+. > -- > Chris Adams <cmad...@hiwaay.net> > Systems and Network Administrator - HiWAAY Internet Services > I don't speak for anybody but myself - that's enough trouble. >
