Sorry, I have a little question about the power consumption measurement's topology in the article "GeForce FX 5700 Ultra goes GDDR3" (http://www20.tomshardware.com/graphic/20040405/gddr3-11.html).
According to the description, THG use "Conrad Elektronik Energy-Check 3000" to do power measurement. I check the "Energy-Check 3000" on web site (http://www.elektronik-online-bestellen.at/energy_check_3000/125319.html), and this one seems can only measure the PSU¡¦s AC input power, not the real system power consumption.
Because the PSU also wastes (consumes) some power during AC-DC transformation, there is a term called "PSU efficiency". A simple way to express this phenomenon is:
"Real System Power Consumption" = "AC Power Consumption (in Watt, not VA)" x "PSU efficiency"
That is, if the real system (MB+CPU+Graphic+HD...etc) power consumption is 200W, and the PSU efficiency = 70% at this moment, than we need about 285W AC power. Every PSU has different "PSU efficiency", and different load has different "PSU efficiency" too. (ATX spec. has some requirements about the efficiency in different loading circumstances. http://www.formfactors.org/).
Because some PSU's efficiency are good (~80%), but others probably don't. (for example, there is some efficiency data here: http://www.oc.com.tw/article/0307/readcmtarticle.asp?id=1637). Using AC power measurement data probably mislead the reader about the real system power consumption to a bigger value.
My question is very simple, if THG measure the ATX's AC power input, then we must know the "efficiency" to get the real system's power consumption value. Or, THG use some other ways to measure the real system power consumption, like "dc current meter"?
PS:
Because the article doesn't provide much detail, please forgive me to waste your time to clarify my confusion. Thank you!
According to the description, THG use "Conrad Elektronik Energy-Check 3000" to do power measurement. I check the "Energy-Check 3000" on web site (http://www.elektronik-online-bestellen.at/energy_check_3000/125319.html), and this one seems can only measure the PSU¡¦s AC input power, not the real system power consumption.
Because the PSU also wastes (consumes) some power during AC-DC transformation, there is a term called "PSU efficiency". A simple way to express this phenomenon is:
"Real System Power Consumption" = "AC Power Consumption (in Watt, not VA)" x "PSU efficiency"
That is, if the real system (MB+CPU+Graphic+HD...etc) power consumption is 200W, and the PSU efficiency = 70% at this moment, than we need about 285W AC power. Every PSU has different "PSU efficiency", and different load has different "PSU efficiency" too. (ATX spec. has some requirements about the efficiency in different loading circumstances. http://www.formfactors.org/).
Because some PSU's efficiency are good (~80%), but others probably don't. (for example, there is some efficiency data here: http://www.oc.com.tw/article/0307/readcmtarticle.asp?id=1637). Using AC power measurement data probably mislead the reader about the real system power consumption to a bigger value.
My question is very simple, if THG measure the ATX's AC power input, then we must know the "efficiency" to get the real system's power consumption value. Or, THG use some other ways to measure the real system power consumption, like "dc current meter"?
PS:
Because the article doesn't provide much detail, please forgive me to waste your time to clarify my confusion. Thank you!