On Jan 15, 6:26 am, William Stein <[email protected]> wrote: > On Sat, Jan 14, 2012 at 3:14 PM, Dr David Kirkby <[email protected]> wrote: > > > > > > > > > > > > > On Jan 10, 4:04 am, William Stein <[email protected]> wrote: > >> On Mon, Jan 9, 2012 at 7:12 PM, Dr. David Kirkby > > >> <[email protected]> wrote: > >> > I'm not sure if this idea will go down well, but I'll mute it anyway. > > >> > I know William has switched off machines (t2.math for example), as he > >> > does > >> > not have the power/cooling for them. That seems a real shame for that > >> > machine to sit and collect dust, when it could be used. > > >> I have the power now. The only machine that is off is t2.math. No > >> other machine is off. That was a temporary measure in light of a > >> *major* electrical issue that arose in the UW math server room, which > >> was beyond my control. If anybody will volunteer to maintain > >> t2.math at a software level, I'm happy to turn it on and give that > >> person root. > > > I'll do my best in the limited time I have available if you switch it > > back on. > > >> > So would William consider paying the electric costs for those that make > >> > servers available, and are not covered by their institution? Would it be > >> > a > >> > waste of money, or good use of money? > > >> How much exactly would the electrical costs be? > > > I have two decent servers decent (both IBM) but want to move CPU from > > the 1U unit to the 2U unit, as the 1U unit has faster processors. But > > I've had to order the necessary heatsink and VRM to make the change. I > > will have a machine with a pair of quad core 3.16 GHz Xeons (8 cores > > in total) and a significant amount of RAM - perhaps as much as 48 GB. > > > Once I get set up, I'll measure the power consumption. Obviously it's > > impossible to give an exact figure for electric costs. > > > But I was more thinking of the general principle that if you want more > > buildbots, then at the end of the day someone has to pay for them. > > Electricity cost is a significant cost of the ownership of servers. > > I think the electrical bill for the house I own is about $20/month > total. Thus I view electricity as being fairly cheap, at least, > compared to water and gas. I don't know what your rates are where > you live, etc., but I might be surprised if running a few computers > costs substantially more than my entire house.
The situation is very different here. Gas is about 1/4 the price per kW hr as electric. We are not even metered for water. I can't get gas to my property, so all heating is either with oil (main source of heat), electricity (for water and cooking), and coal (very occasionally used if other forms of heating fail). I pay about £0.11/kW hr for electric. I don't know what a server with 48 GB RAM and 8 cores would use, but lets say 500 W. So over 24 hours I'd use 0.5*24*0.11=£1.32 or $2.02. So that's just over $60/month to keep a server on. So whilst you use $20/month, keeping a single computer on that uses 500 W would cost me 3 x as much. It seems if you want buildbots, and are willing to pay the cost of them, it would be better if they were located where you are. Dave -- To post to this group, send an email to [email protected] To unsubscribe from this group, send an email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
