Building an energy efficient PC

tapout72 · Apr 12, 2013

I'm looking to build a new pc. The PC will be on 24/7 with the primary function to run Blue Iris software for my 5 IP megapixel security camera system. I'm also would like it to twilight as a lightly used HTPC.

My requirements for the system:

1) Must be energy efficient. My current 4 year old setup currently pulls 180watts which is way too much power for constant use. So this means trying to get by with onboard graphics if possible. I also would like to use a 80plus certified PSU.

2) Blue Iris recommends an I7 processor and at least 8GB of ram.

3) If possible, I would like to go with a smaller form factor. It doesn't necessarily have to compact but I want to avoid a large bulky tower.

4) I would like a quiet system, if possible silent. Since this will be on 24/7 I also want to avoid all those bright nonessential LED lights that are brighter than a Christmas tree.

5) Finally, price is not a huge factor. I don't want to spend anymore than I really have to but I'm willing to compromise for power and efficiency.

I'm looking at the I7 3770 processors. Is the energy consumption that much different between the 3700K vs 3770S and 3770T versions?

I would appreciate any suggestions you may have. Thanks in advance!

asalikus · Apr 12, 2013

Only the 3770k it self pulls 77w so I don't know how you'll be able to find a system that consumes less than 180w...

tapout72 · Apr 12, 2013

asalikus :

Thats 77w TDP max right? My old system pulls 180w at 15% CPU utilization. I don't plan on running 100% CPU utilization. I was also hoping reduce the wattage by eliminating a dedicated graphics card and using more efficient SSD and HDD.

Are you telling me I can't build a new I7 PC that would run less than 180watts constantly?

mbreslin1954 · Apr 12, 2013

Dude, that's maximum thermal power draw. At idle it will probably use about 7 watts, plus the motherboard will use a few, plus the hard drive will use a few watts.

My first 24x7 server was based on a Sandy Bridge I5-2500 CPU and an AsRock motherboard, and with an 80-plus certified PSU and one 1 TB HDD, it drew between 30 and 36 watts of power idling from the wall (usually right around 36 watts, and as a server it idled most of the time). It ran with no monitor so that was pretty much it, 36 watts. The Ivy bridge CPUs are even more energy efficient.

The "T" versions of Intel's CPUs are the low power versions, the maximum power draw from an i7-3770T is 45 watts, compared to the 77 watts of the i7-3770k. Of course to get that lower power usage, the "T" runs at a normal clock speed of 2.5 GHz (3.7 GHz turbo) vs. the 3770k's 3.5 GHz (3.9 GHz turbo).

Go to this site and type in your processor numbers in the search field and it will bring up the specs. You can then click on the "Add to compare" link and get a comparison field of up to four or five CPUs, side-by-side. Just pull up a CPU, click Add to Compare, then pull up another, etc. When you are at your last CPU, click on the "Compare Now" link and you will have all the specs from all your CPUs side-by-side.

http://ark.intel.com/

(go to the "Type here to search products" search field and type in, for example, "i7-3770" and it will bring up all models that begin with i7-3770, including the "K" and "T" versions, then you select which one you want to view the specs for -- you'll need to use that format, "i7-xxxxx" or "i5-xxxxx").

So you'll have to trade off speed for power draw. Sorry, but if you need a lot of CPU horsepower to run your app, then you'll draw more wattage. If you can do with a less powerful CPU, then you'll draw less power. Typical engineering trade-off.

mbreslin1954 · Apr 12, 2013

So you can probably run your security server for 40 watts, give or take, the price of leaving a 40 watt light bulb running all the time. Not bad, when you think about it.

tapout72 · Apr 12, 2013

mbreslin1954 :

That's my goal. Now I just gotta find the right parts to complete the system.

TenPc · Apr 12, 2013

Are you going to record the input from the video cameras? If so then your hdd would have to be set running tand software required to record the input. You can't run an idle pc that is recording video images. If the video camera software requires i7 then that means it needs extra power to support the programs so using less than the usual power requirement as for a regular Pc would most likely fry something, surely!

Consider a GREEN PSU that will power down when the PC is idle. You could also set the PC only to wake when movement is caught on the cameras however, if the cameras are moving constantly then there can't be any sleep mode activated.

You ram would require 100 watts the cpu about 100 watts, and the motherboard about 50 watts and the hdd about 15 watts and other things as well so 180 watts is not really a lot for a PC, even back in 1999 the PSU was 200 watts.

mbreslin1954 · Apr 12, 2013

"You ram would require 100 watts the cpu about 100 watts" ???????????

Dude, the CPU he's looking at is either a max of 45 watts, or a max of 77 watts, what are you smoking?? Modern 1.5 volt RAM does NOT use 100 watts. Wow.

tapout72, ignore the previous post. He doesn't know what he's talking about.

TenPc · Apr 12, 2013

mbreslin1954 :

The Pc will be required to record video images so the cpu would not be in idle mode. The cpu would have to be one that is more than 7 years old for it to be less than 80 watts,

http://www.anandtech.com/show/4083/the-sandy-bridge-review-intel-core-i7-2600k-i5-2500k-core-i3-2100-tested/21
According to the table, an i7 CPU 920 uses 81 watts idle and 153 watts on load.

As comparison -
Intel Core i7 880 (3.06GHz) 3W idle and 106W load.
Intel Core i7 2600K @ 4.4GHz 5W idle and 111W load.

The ram itself is not 100 wats, more likely about 10 watts.

Of course you can disregard everything that I've said, I was just trying to outline the possible risks of having a system under-powered and possibly causing damage to your system and your recordings would be for nought.

mbreslin1954 · Apr 12, 2013

My desktop workstation has the following components:

i7-2500 (Sandy Bridge) CPU
8 GB RAM (PC3-12800) DDR3 Patriot Memroy
Rosewill Capstone 80 Plus Gold PSU
AMD Radeon 7950 GPU
WD 500 GB HDD
256 GB Samsung 830 SSD

According to my kill-o-watt meter, my system uses 54 watts running HWinFO64 hardware monitor and Google Chrome (and tons of crap like DropBox, AnyDVD, Norton, etc.).

Under full load, when doing a video encode running HandBrake, pegging all four of my CPU cores to 99%, my system uses 110 watts.

BUT, according to Tom's Hardware, a typical Radeon 7950 video card at idle uses at least 15 watts at idle.

http://www.tomshardware.com/reviews/radeon-hd-7950-review-benchmark,3207-9.html

That cuts down my full system load power usage to about 95 watts, and my idle state to 40 watts.

As soon as my kids are finished watching streaming video from my home server, I'll shut it down and put the watt meter on it, then re-boot it and give you numbers from my i5-3770 with two 3 TB HDDs and integrated video, which is very similar to what the original poster (OP) is considering doing. I'll also get the numbers for running HandBrake on it, maxing out all eight logical cores to 99%.

mbreslin1954 · Apr 13, 2013

My server hardware is as follows:

Intel i7-3770 CPU (4c/8t)
8 GB RAM DDR3
Intel HD 4000 integrated video
2 Western Digital WD Green WD30EZRX 3TB IntelliPower 64MB Cache SATA 6.0Gb/s HDDs
60 GB OCZ Vertex SSD (Windows Server 2012 OS)
Antec Earthwatts EA-380D Green 380 watt PSU
2 Intel PCI NICs (network interface cards)

The system idles at 40-43 watts
Under full load (as high as I can get it, all 8 logical cores running between 90-98%), the system draws 105-107 watts. This is running a HandBrake video encode.

Since this is what you were considering buying, I think it gives you a pretty good idea what to expect. What's not clear is how hard your software is going to be working recording your video. I doubt the recording of video camera footage will make any kinds of demands on your CPU. I've installed NUUO video recorders (NUUO NVRMini) recording four mega-pixel IP cameras (Axis) over Ethernet, and those systems use an Intel Atom CPU running embedded Linux (recordings are in H.264). And those NUUO systems also play back recorded video while continuing to record new video.

Aside from running Handbrake on my server, I cannot get the average CPU utilization to climb above 7%. Running a virtual machine of Windows 7 as a digital video recorder for my cable TV is about all I do with my system, other than act as a file server and print server. Well, and serve/stream video for our home theater projector. But really, it essentially idles most of the time, except each night when I re-encode recorded TV (.wtv files) into .mp4 files with HandBrake (they're about 60% the size of the originals).

tapout72 · Apr 13, 2013

Thank you both mbreslin1954 and TenPC. I appreciate both of your input.

mbreslin1954, I'm actually considering a setup very similar to your I7-3770 server. I've read that WD Green HDs have a lot of issues. I'm might just go with the black versions. What MB are you running on that setup?

I haven't really pushed the software much yet. On my current I7 920 box, I have three 1 megapixel cameras running. 2 of them are triggered on motion to record at 720p resolution at 15fps. The last camera is recording 24/7 D1 resolution at 30fps. With that load CPU utilization is at about 15% constantly. I plan on adding 2 more megapixel cameras to record on motion at 15fps. With the I7 920 box, this configuration kicks the CPU utilization to 15% and 180watt per hour. I can run the same config on my I7 2630QM laptop with the CPU also at 15% but only uses 30-35watts per hour.

I'll see how the new I7 3770 PC performs and can taper fps to reduce the software demands on the PC if necessary.

mbreslin1954 · Apr 13, 2013

I'm running a Gigabyte GA-Z77-D3H. I'm not wedded to the disks, they just seemed like a good price at the time. All my data is on the first 3 TB HDD (I'm using about 2 TB of the 3 TB), and Windows Server backup runs every night, doing an incremental backup to the second 3 TB HDD. I don't care if one breaks, I've got two copies of the data, the odds of both disks failing at the same time are really, really small, and I have spare 2 TB HDDs if I need them (they used to be my main drives before I upgraded).

The NUUO video recorders I installed are recording continuously at 5 frames per second, a couple of the IP cameras are 2576x18xx or thereabouts, the other two or three are 720p or a little higher. And the video recorder is an Atom CPU, although the OS is a stripped down version of Linux, so no overhead.

Your i7-920 is first generation Core architecture, and uses twice the power of the i7-3770 (130 vs. 77 watts). Given that the 3770 gets much more work done per clock cycle, I'm guessing your current 15% CPU load would drop quite a bit. Even if it only dropped to 10%, it's only going to use half the power at the same CPU load. Plus you must be running with a graphics card, or integrated graphics on the motherboard. Either will draw more power than the 37770 on-die GPU. Also, Ivy Bridge motherboards have less chipsets (more is in the Intel CPU) so the mobo will also draw less power.

TenPc · Apr 13, 2013

Just as a matter of interest, is it really worth saving $6 per week on an under powered PSU that might cause issues?

mbreslin1954 · Apr 13, 2013

So an Antec 380 watt PSU is under powered for a system that never draws more than 110 watts max from the wall, and usually draws no more than 50 watts? Assuming the Antec is 80% efficient, then it's only actually providing 85 watts to the system.

TenPc · Apr 13, 2013

I wouldn't use a 380 wat on an i7 Pc with 8gb of ram. I doubt that your cd/dvd drive would work. I got a Dell DN061 that wouldn't work with a simplet Gt8600 video card and 4gb of ram with Vista x32, sata cd/dvd drive and the PSU was only 305 watts. When I replaced the PSU with 550 watts, all work well.

I'm just saying that oyu are heading for trouble with a high guzzling power hungry motherboard with only 380 watts PSU that you seem to be wanting for "energy" saving reasons that you could do better saving energy by not streaming video (go buy your own dvd movies frm the store) and other things like video cameras for whatever reason, you could just as well use Windows 2000 for that sort of thing on a Pentium 4 and get away with a 300 watt PSU, using web cameras.

You'd probably be using more energy by using a lower watt PSU than one that doesn't need to strain for power when it is required. You could use the cx430 watt, just to be on the safe side (although if you use a video card, you would be better with the cx600 watt).

The total amount of power drawn at boot up is the maximum amount of watts that each component could require so if your max load total is more than the 336 watts on the 12v rail for the Antec 380 watt PSU then your Pc will fry. The max load only lasts a second or two but you will smell something funny when the psu strains to give the capacitors their fill. Also, the PSu will be rather noisy if it is running at almost peak power most of the time.

Anyway, most people disagree with me so you should disregard this and all of my replies.

Sorry to be so argumentative, it's probably not the sort of reply you were expecting.

tapout72 · Apr 13, 2013

TenPC,

Out of curiosity, what is experience building systems? I get the feeling you're experience and advice is geared towards gaming rigs. I am in no way doubting your knowledge, in fact I like to hear arguments from different sides.

Have you previously built or designed systems with energy efficiency in mind?

mbreslin1954 · Apr 13, 2013

tenpc,

I'm sorry, but you really don't know what you're talking about. You doubt my CD/DVD drive would work??? Are you kidding me? Trust me, it's worked for the past 11 months without a problem. I rip DVDs and Blu-rays from it all the time. I've built around 80 computers over the past 18 years, beginning with the Pentium II, so I've had some experience. I have a family of six, we have six desktops in the house, and from 1999 through 2006 I was building about five a year, as CPU horsepower increased by about 50% each year. Now that it's down to 10-12% improvements each year, it's not worth it.

But really? You're comparing a weak, no-brand PSU in a Dell, which are sized to barely work with the pre-built PC, with no extra power capacity (that would be a waste of money from their point of view), to which you add a discrete video card, and you're surprised the original Dell PSU couldn't handle it? The mind boggles.

Let me repeat for you, since it seems you didn't understand: My rig draws between 50 and 107 watts of power from the wall, which means my PSU is providing from 40 -85 watts to my system. It is a good, brand-name PSU capable of supplying 380 watts, which means that at max load it's only supplying about 23% of it's rated power, and you think by DVD drive doesn't work? My mind boggles at you.

Now to be fair, if I added a power-hungry video card to my system that could draw 250 watts of power under heavy load all by itself, I might have a problem. BUT IT'S A SERVER! It will never have a high-end video card! If it ever does I will change out the PSU with one of the three unused, higher capacity extra ones I have in my cabinet!

Building an energy efficient PC

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