How do I find the power consumption of a sound card?

Question

I have a custom built desktop PC where I carefully chosen the parts so that it is still relatively powerful but has very low energy consumption. Now after I see that the inboard audio is not able to put out a DTS signal, I looked for a good sound card.

Looking: 24bit bla bla -122db noise reduction bla bla 5./7.1 bla DSP bla DTS bla EAX bla OpenAL bla whatever.

But absolutely no information about power consumption !

I could not believe my eyes. I tried it with both Creative and Asus cards.

The next option is to ask the vendors directly but a) that will be cumbersome b) does not help the next person asking this question and c) I wonder why the vendors do not give the information

So how do I find out the power consumption of the sound cards without buying and testing them ?

Solution

Rather than answering "How" - I'd probably be better off explaining why the statistics don't exist, and why you shouldn't actually worry about this.

The simple fact is, compared to other components, Its probably negligible. There's no up to date statistics I can find with a quick search, but there's a comparison with older card models that shows at most a 15 watt difference between a onboard and discrete card and about 5w between cards adn the wall. Though, there were also differences in processor usage, and this reflects power usage of the system rather than the sound cards themselves

Theoretically you would use between 10W (for a half height x1 slot) and 25 watts (for a full size x1 or bigger card) maximum for a PCIe card and 5W for a USB device I'm referencing these numbers from the wikipedia - I used the pci e page, and a worst case scenario of 1A for the USB device, since they typically run from 0.5 to 0.9A.

In comparison, my desktop speakers use about 12W for a 2 speaker and no subwoofer set up, and the amplifiers for your speakers probably are going to use more, even if they're class D or T rather than the class A, B or AB designs.

That is to say, no one bothers with sound card power usage because it dosen't matter.

If you really wanted to minimise - consider this, a great headphone amplifier chip of the sort you would find in a high end sound card is only 1.5w, and I can't find overall power requirements for a DAC chip in a casual search (but quite a few good ones are usb powered, so we can assume a maximum of 5w) and that's likely one of the more power hungry 'add on' parts that would differenciate a sound card.

Anything with a heatsink is likely going to draw more power (and is probably a good, strange rule of thumb in this case), so all other specs being equal, go for the one that looks simpler, and has just the features you need. It'll end up being cheaper, and probably runs with less heat.

Comments

[Thorsten S.]

Citation ? "Maybe" is not good enough. I know that CPU/GPU normally eat most of the power, but I need a quotable reference. And why exactly is the power consumption not in the technical specs ?

[Thalys]

It may be negligible compared to other components - unlike a video card, it probably runs comfortably under 25 watts(the maximum for pci-e), and more likely 10 watts (the maximum for a x1, half height slot) . For that matter, you can get a reasonable sound configuration with USB, and that's 5 watts at most.This is outdated as hell but techreport.com/review/14500/asus-xonar-dx-sound-card/5 has some statistics on older models

[Thorsten S.]

@JourneymanGeek Why not add this comment as an answer ?

[Thorsten S.]

The given comparison is for me sufficient to support your conclusion. I have accepted the answer.