HTPC Gurus: Help with Power Draw Calculation Please.

Howdy all,
I'll be installing a Pico PSU in my HTPC soon for the purpose of clearing things out and maximizing space and airflow within my mITX case.

THIS one.

My System is as follows:

CPU- E8200 (Stock w IEST, C1E enabled)
Mobo - Zotac 9300 D-E
RAM - 2x2GB Gskill DDR2-1000
HDD - Seagate Momentus 7200.4 250GB 2.5"
Optical - LG Super-Multi 22x DVD Writer

I've yet to purchase a killawatt meter to get an idea of how much my machines are pulling from the wall, but I did some research on the net tonight and came up with some numbers.

Below is a list of power draw numbers I found for each component and the source of the info in each case. If I could, I'd like to get some opinions based on experience on whether or not you figure these numbers are accurate, and if not, why not.
I'm fairly sure the proposed PSU will be more than sufficient, but there's also a rather large curiosity factor involved and I'd really appreciate your input.

CPU - 65w TDP (27.7w 100% Load)
http://www.xbitlabs.com/articles/cpu/display/intel-wolfdale_11.html


Mobo - ?

HDD - 2.25w (5v, .451a)
http://www.techwarelabs.com/seagate-momentus-7200-4/

DVD Drive - 5-15W
http://www.silentpcreview.com/article265-page4.html

RAM - 24w Max Usage(4GB @ ~3w per 512mb) ~10w typical
http://www.silentpcreview.com/article265-page4.html

SYSTEM - E7200 + GF9300 + 2.5" hard drive + 1GB RAM pulls less than 70W from the wall at full load:
http://www.silentpcreview.com/article892-page5.html

The only question mark is the motherboard. Chipset, integrated GFX etc.
I figure, assuming everything running full load at same time from HDD with 2GB memory usage= ~40w+Mobo Power draw.
~65w(from figure above)-40w=~25w for Chipset and GPU. This seems a bit high, but I'm really not sure.

So whataya figure, am I way off base?
Thx in advance for any input you can provide.

EDIT: Just found THIS. Uses an E8500, a full size Barracuda 7200 and 2GB of DDR2-800 for a total of 86w under load.
Considering this, the 65w system total under load for my system doesn't seem too far off assuming the Optical drive's not running.

In light of the information you provided, I can't see how your system could draw more than 100w.

DDR2 is quite a power hog, but a laptop hard disk drive is a nice choice for low-power consumption.


Good luck!

Yeah, I knew DDR2 kinda sucked the juice, but I'm not sure exactly how the power consumption scales exactly. For example, if we assume the 3w/512mb and I've been monitoring Everest and found that the typical memory usage while say... watching a movie from the HDD is ~40%, then 40% of 4GB is 1.6GB or ~9.375w?

As for the HDD, I just couldn't justify grabbing a 120 or 256G SSD for a HTPC until price per GB comes down, so I got the next best thing. I had my eye on the WD Scorpio Black 320G ~$95, but again couldn't justify the premium over the Seagate ~$65. Gotta say, so far I am really impressed with the performance, low noise and low heat from this thing. I have it in one of THESE in the front of the case and I can't hear it. When I point the Digital Thermometer at the bare drive while it is busy reading or writing I see 34-38deg max. Nice little drive for the money.

Regardless dostov, thank you for being the first of 52 people to view and actually reply to my thread.

Bump. Any one else have some experience with power draw of typical HTPC components?

baditude_df said:

Bump. Any one else have some experience with power draw of typical HTPC components?

Click to expand...

The HTPC in my sig draws (I think, it's listed) 60 idle, 72 bluray at the wall, so figure something like 48-58 at the psu. I can't imagine your planned build coming anywhere near 100 watts at the PSU.

Thx Ratbuddy.
The build this thread refers to is actually my current HTPC. Right now I'm using the PSU tha came with the enclosure . It's a 250w mITX PSU, but even with it's tiny FormFactor, it takes up too much room and makes things harder to get at that they really need to be.
I plan on removing the PSU and covering the hole with an acrylic plate which will have a hole drilled for fitting the picoPSU plugin.
I've already removed the full size HDD, and freed up the whole right side of the case where the ventilation holes are so I can install a couple of 80x11mm intakes to go with the exhaust fans on the other side. By the time I'm done, there should be a good amount of work room and airflow. That CPU and chipset get pretty hot, especially in the summer.

not sure this will help, but....

http://www.extreme.outervision.com/psucalculatorlite.jsp

scoobydoo said:

not sure this will help, but....

http://www.extreme.outervision.com/psucalculatorlite.jsp

Click to expand...

Yes it does to a certain extent and I have used this calculator b4. Obviously it's a bit generic though and not sure how it would calculate a mITX mobo with integrated graphics.
Sorry for thread resurrection, but I have renewed interest in revamping my HTPC and a picoPSU and power brick are tops on my list. I'm basically trying to clean out the interior of the case and maximize airflow, so the SFF PSU has to go.
If anyone else has input, please speak up.