0Eficiencia PSU 2 — A typical gaming PC

Fol­low­ing on from the slight sur­prise that a new PSU is a poor invest­ment for a low power PC I decided I’d reas­sure myself that an effi­cient PSU is a good invest­ment for a typ­ic­al “enthu­si­ast” PC.

To do this depends on the con­fig­ur­a­tion, how much time the PC spends on, and how much time it spends being heav­ily util­ised. I’m basing this on a fairly-high power single-GPU sys­tem with a Core i7 CPU and a Radeon 5870. I’m also going to assume the sys­tem is oper­ated from 3pm — 11pm week­days and 9am — 1am week­ends, mak­ing for a total of 72 hours a week. I’ll also assume the sys­tem spends 50% time idle and 50% full-load.

los sistema en cuestión pulls ~80w idle and ~340w under full load. Find­ing effi­cien­cies for this is tricky, so the value will be roun­ded up to 400w (la PSU’s in ques­tion don’t vary greatly between 300w and 400w)

All of these estim­ates are delib­er­ately on the high side. I expect a typ­ic­al PC will spend more time off, more time idle, and wont be loaded as intensely as the example. Most sys­tems also use lower power CPU’s and GPU’s too.

The fig­ure for the gen­er­ic PSU is based on the min­im­um require­ment and is there­fore a worst case. Even with a very poor effi­ciency PSU the AC draw from the wall won’t increase as the DC draw decreases. I have cal­cu­lated a best-case yearly sav­ing, based on a kWh charge of 10p.

A new PSU in this scen­ario is prob­ably not advis­able on a fin­an­cial only basis. Even with quite a lot of heavy use, y comparando los más eficientes PSUTiene el peor presupuesto ATX PSU can per­form the sav­ing will take around 5 years to recoup. A real world upgrade is unlikely to net this much saving.

Si está considerando reemplazar un PSU mi consejo seria no molestarse, a menos que tenga razones adicionales. Si está comprando nuevo, entonces vale la pena pagar más por un mejor PSU, dentro de lo razonable. Por supuesto, si desea la eficiencia por otras razones. (Ruido bajo, fuego lento) entonces esos factores pueden hacer que la diferencia de valor sea irrelevante.

Actualizar (25-Dic-2011)

Added the HuntKey Jump­er R90. Whilst it is sold as a 300W PSU, it does work slightly above spec, espe­cially if well cooled. This PSU does make a bit of dif­fer­ent to the con­clu­sions. It pro­duces sav­ings of over £20, which is a sig­ni­fic­ant pro­por­tion of the price of the PSU!  Un período de recuperación de 2 año, with an expect­a­tion that elec­tri­city prices will con­tin­ue to rise would cer­tainly be worth think­ing about. How­ever, the HuntKey isn’t spe­cified high enough to really provide for the con­fig­ur­a­tion spe­cified in this scen­ario, and as such we could­n’t recom­mend run­ning it bey­ond its rating.