ces wrote:dhanson865 wrote:No batteries involved, what he means is that there is an inefficiency converting from AD to DC (all computer parts run on DC power) and that has to be taken into account to compare numbers.
The
AMD Fusion on an Asus E35M1-M Pro Motherboard uses
a total of 18 watts AC at idle, and
a total of 28 watts AC under an average load (H.264 playback)
http://www.silentpcreview.com/article1167-page5.html
vs
The Intel Core
i5-2500K running on an Intel DP67BG motherboard uses
a total of 16 watts DC at idle, and
a total of 23 watts DC under an average load (H.264 playback)
http://www.silentpcreview.com/article1148-page5.html
No, you can't compare those two numbers like that. You either have to convert the Intel DC back to AC or you have to convert the AMD AC to DC.
HFat says we can rely on the AMD numbers being truly AC, so to convert to DC we can take a range between 66% and 72% efficiency per the reviews use of a Seasonic SS-400ET power supply (totally unrelated to any technology used by Intel or AMD, it just happens to be what SPCR used for that particular review).
18 watts AC x 66% = ~12W DC
18 watts AC x 72% = ~13W DC
28 watts AC x 66% = ~18W DC
28 watts AC x 72% = ~20W DC
so The
AMD E-350 on an Asus E35M1-M Pro Motherboard uses
a total of 18 watts AC at idle, and
a total of 28 watts AC under load (H.264 playback)
and we assume by doing math that translates to something like
a total of ~12W watts DC at idle, and
a total of ~19W watts DC under load (H.264 playback)
versus
The Intel Core
i5-2500K running on an Intel DP67BG motherboard uses
a total of 16 watts DC at idle, and
a total of 23 watts DC under an average load (H.264 playback)
Or we could convert the other way and figure out how much higher the Intel used using math like
16 watts DC / 66% = ~24W AC
16 watts DC / 72% = ~22W AC
28 watts DC / 66% = ~42W AC
28 watts DC / 72% = ~39W AC
and get to something like
a total of ~23W watts AC at idle, and
a total of ~40W watts AC under load (H.264 playback)
It'd be clearer if the articles with conversion to estimated DC usage had the raw data somewhere in an appendix, footnote, or sidebar of some kind. It'd be clearer if all the articles had the same conversion.
I'm not really sure what you are trying to say with all that TDP talk and the rest of the post below that.
You seem to be missing the concept of translating from AC power consumption to DC power consumption.
AC power comes from the wall to the power supply. The power supply converts it from AC to DC and sends it out to the parts inside the PC. How efficient this process is varies from Power Supply to Power Supply and from low wattages to high wattages.
If I tell you that my PC draws 72 Watts at idle and say nothing else your first question should be how did I measure that and you should expect an answer that says with a Kill-a-watt meter (or similar wall plug device) which measures AC or by probes at certain contact points inside the PC which gives a number in DC (but is hard to do and requires measuring every possible sub-component at the same time if you want total system consumption). When I answer Kill-a-watt (AC) you should have a follow up question of what power supply am I using. So you can do figure out if I'm drawing 72 watts because I have an inefficient PSU or if the rest of the system is power hungry (or a combination of both).
In a shorter version if I tell you 72 Watts at idle you should come back with the question "AC or DC?". And I'd say AC (because nobody measures total system consumption in DC).
As far as I'm concerned we'd be having this conversation if there was only one power supply on the entire planet and it wouldn't matter if it were a 650W Seasonic or a 1200W OCZ or a 20,000W Taipai Electric (OK, I made the last one up). This isn't about how to choose a Power Supply this is about how to convert from one type of measurement to another.
Maybe the table at
http://www.silentpcreview.com/article28-page4.html would make it clearer to you the relationship between AC power and DC power in a PC?
I hope that clears it up for you. I honestly don't know where the Fusion E series compares vs what Intel part. I have to stop and read all the articles to catch up. I have faith in the power of capitilism to adjust the price of both parts to reflect their advantages/disadvantages.
But tonight being Valentines my girlfriend will expect me to spend some time off the PC so I won't be trying to predict the market right now.