-------- Original Message -------- Subject: Re: [CentOS] Power-outage From: m.roth at 5-cent.us To: CentOS mailing list <centos at centos.org> Date: Friday, July 01, 2011 9:57:41 AM > Blake Hudson wrote: >> From: m.roth at 5-cent.us >>> Nicolas Thierry-Mieg wrote: >>>> Colin Coles wrote: >>>>> On Friday 01 July 2011 12:05, Timothy Murphy wrote: >>>>>> Any advice or suggestions gratefully received. >>>>> If you are thinking of the UPS route a caveat: I have several HP >>>>> servers and most of them will not work on cheap UPS's as they do not >>>>> produce the pure sine wave modern HP machines require but rather a >>>>> crude stepped voltage. >>>> perhaps naively, I'm surprised: doesn't this mean they put crappy PSUs >>>> in those servers? >>>> I thought decent PSUs were expected to deal with dirty input AC? >>> I agree. Esp. since, other than in datacenters, *most* electric power is >>> pretty crappy. >> I would have to disagree. They probably put high efficiency active PFC >> power supplies in the servers to save YOU money. You could buy a cheaper >> PSU that will not be as efficient and would thus cost you more in >> electric costs and create more heat (which would again cost you more in >> AC bills and reduce server density). The active PFC supplies are > Except that I expect datacenters to have conditioned power, and so they > can cheap out with the servers, with the same expectations. And I would > expect consumer-grade systems to not have fancy power units, but ones that > won't die on power irregularities from the electric co's. > <snip> > mark I think you missed the point - While manufacturer's could (and probably sometimes do) "cheap out with the servers" power supplies, it is not in your best interest (or their's). More efficient PSUs create less waste heat and draw less power which means higher density, more performance, etc. This is more important in the server space where the computers are on 24/7 and tightly packed into racks. More efficient PSUs cost more upfront than inefficient ones, which mean that Dell/HP/etc can probably make a higher profit. In the long term, you may be saving $50-100 per server per year on reduced electric and associated costs. If you're in a colo with power draw restrictions, you may be saving even more.