March 23, 201313 yr What is the most accurate tool or mathematical equation to calculate a power supply for unRAID? I'm looking for something that's dynamic. Thank you
March 25, 201313 yr I've used http://www.extreme.outervision.com/psucalculator.jsp for several years now. I have the pro version, but the lite version is the same thing it just lacks individual rail amperage data and a few other features.
March 25, 201313 yr I've used http://www.extreme.outervision.com/psucalculator.jsp for several years now. I have the pro version, but the lite version is the same thing it just lacks individual rail amperage data and a few other features. Apparently my build that's running a 750W PSU and maxes out at 445W when everything is in max use requires a 761W PSU. Decent, I guess, but, meh.
March 26, 201313 yr I've used http://www.extreme.outervision.com/psucalculator.jsp for several years now. I have the pro version, but the lite version is the same thing it just lacks individual rail amperage data and a few other features. Apparently my build that's running a 750W PSU and maxes out at 445W when everything is in max use requires a 761W PSU. Decent, I guess, but, meh. Didn't make it, but one must understand inrush, capacitor aging, and the fact a power supply is most efficient at 50% loading.
March 26, 201313 yr I've used http://www.extreme.outervision.com/psucalculator.jsp for several years now. I have the pro version, but the lite version is the same thing it just lacks individual rail amperage data and a few other features. Apparently my build that's running a 750W PSU and maxes out at 445W when everything is in max use requires a 761W PSU. Decent, I guess, but, meh. Didn't make it, but one must understand inrush, capacitor aging, and the fact a power supply is most efficient at 50% loading. I don't know where you get the "most efficient at 50% loading" figure from, but it is seldom true for modern switched mode power supplies. It is down to the detail of the design and will change according to the loading and also according to the input conditions. For example, a switching supply running from a lower mains voltage is generally slightly less efficient than one running of a higher mains voltage. (The increased losses are generated in the synchronous rectification stage just after the main switching inductor due to the correspondingly increased switching currents at lower input voltage. It sounds back to front until you look in detail at how buck regulators work.) If you study the power efficiency curves of switching power supply designs you will see that many such supplies will be more efficient towards the upper end of their working range but often with a sharp drop-off at the top 10 to 20% of the loading range. However, it is generally not considered good practice to continuously run a supply at or near its maximum loading, with figures in the region of 50% to 70% loading being regarded as very much better from the point of view of long term reliability. This is also to take into account the effects of ageing on components, especially capacitors (as you say) which are one of the main causes of power supply mortality. Thus a system with a total loading of around 400 - 450W would be well matched to a power supply in the 700W range, and would normally be expected to have a much longer working life than one using only a 450 or 500W supply. At the other end of the range, most power supplies are generally relatively inefficient at very light loadings, so it makes sense to avoid spending on a 750W supply if a system only draws (say) 200W maximum and is spending most of its time idle at perhaps only 50W loading.
March 27, 201313 yr http://www.tomshardware.com/reviews/power-supply-psu-review,2916-5.html http://www.tomshardware.com/charts/power-supplies,26.html http://www.onsemi.com/pub_link/Collateral/TND359-D.PDF
March 27, 201313 yr Interesting. But all that proves is that a switched mode power supply with a 50% load is more efficient than with a 20% load or 100% load, and that statement is true because those are the only three data points provided. What the data does not show (I think it is not required for the bronze/silver/gold classification) is that a switched mode power supply will generally be more efficient at (say) 75% load than at 50%. And that was simply my point - quoting that maximum efficiency is found at a 50% loading is not an accurate reflection of how these things actually work. (Ask any good power supply designer.)
March 30, 201313 yr http://psucalc.tk/ Its a tad outdated for CPU's, but the important thing is that it does break down the 12V rail into peak and average/idle ratings.
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