Hi everybody!

I'm planning a silent sff build - and I hope I can ask for your help. The computer will mainly be used for daily routines such as web and media playback (music, 1080p). From time to time I'll be doing some more demanding stuff, but nothing that demanding. The important thing is to achieve a small and silent system, meanwhile something that will be usable for daily stuff for many years to come.

Currently, I'm struggeling to decide what to get when it comes to cpu and motherboard. I'm between a H77 board and the i3-3220T (35W) or a Z77 board and the i3-3225 (55W). To specify, I'm looking on ASrock H77M-ITX respectively ASrock Z77E-ITX - but nothing is certain (i.e. other brands can be suggested). Would the second mobo+cpu option be able to be undervolted and would this be worthwile (to keep noise/heat to a minimum)? How does one know if a motherboard has the ability to undervolt (what to look for?) and would one need to underclock as well?

Other probable components
case: Antec ISK-110 (90W external psu)
ram: 2 x 4GB 1.35V
ssd: 256GB sata III
os: Linux

Thanks for your time!

I did a search for "can you undervolt ASrock Z77E-ITX" and this was the first link.

Looks like the answer is yes. So, if that's the mobo you like, go for the i3-3225.

Hi, thanks, good to know (note to myself: practice google skills).

I've read in other posts/forums that the new (ivy and also sandy bridge) intel cpu:s are effetive to the point that undervolting (which I've never done, nor have I overclocked/underclocked) would not bring any real benefits. Can somebody comment on this? Would I see any benefits from undervolting the i3-3225 (in order to minimise heat/noise = lower fan speed/noise). Has anyone here undervolted the i3-3225 (or similar i3 cpu)?

Fyi, the i3-3220T is an undervolted and underclocked i3-3220. That's how Intel meets the 35W TDP. You won't see a difference in power use at idle.

Thanks CA_Steve for your comments!

Would one be able to reach the same 35W TDP as Intel with the i3-3220T @ 2.8GHz if one were to undervolt and underclock a i3-3225/i3-3220 55W TDP @ 3.3GHz? Yeah, that sounds probably stupid - why not go with the cheaper i3-T/h77-solution to begin with? Well, I'd like to have both options available (to be in control of the process), try to find out where performance and heat/noise would meet my requirements. I could obviously just get the z77/i3-3225 and find out, but they are in the higher end of my budget and as I have never done any under/over-volting/clocking before I really don't know what to expect. Therefore I appreciate any comments you may have

I haven't had the opportunity to personally mess with Ivy Bridge underclocking/volting. Maybe some others will chime in with what they've seen/done. Here's SPCR's take on Sandy Bridge, comparing an undervolted i5-2400 to the i5-2400S and i3-2100T grades.

Load power will be dependant on a couple of things beyond just CPU freq and voltage:
- mobo's VRM circuitry. Mobo's designed for overclocking tend to have more VRM phases and this additional circuitry means higher idle power and in normal use, higher load power. Also, some boards just have better/more efficient VRM designs than others. The downside is some of the sparser boards don't allow for undervolting/clocking.
- lots of features on the mobo means higher power use. Multi GB NICs, wireless, Thunderbolt, etc all add up.
- your system will be mostly idling. Web browsing and music streaming just doesn't take a lot of CPU cycles.

Here's a comparison of z77 mobos at Hardware.info. There's 30W difference between the lowest power use board and the highest...

To sum up what was said above, if you want to save power get an Intel or MSI board and get a board with less features.
The CPU will only make a difference at load and underclocking (there's no real point in undervolting at low speeds) will take care of that. You can underclock in software.

Unless you truely want the very best efficiency, the only point in buying a *T CPU as far as I can see is if you have an even less powerful PSU than yours. Note that some people disagree and believe there is no point to the *T CPUs whatsoever.

Also note that undervolting is potentially unsafe. I'm not talking about fires! Just occasional errors and crashes...

edit: in case you didn't know, i3 CPUs aren't the cheapest and are actually overpriced relative to the cheaper 1155 CPUs

Thanks for both your comments - I appreciate it!

Saving power is not my main aim, silence and small form is, and that the computer will be up to most tasks - excluding gaming - for many years to come. In other words that it will have some 'computing reserve' besides ordinary web/media stuff. But yes, I do at the same time want a computer that is using less power than the average computer. Thenagain, I am assuming that these things are connected; using more power/watts more or less equals creating more heat (possibly more noise); using less power, one probably has a more silent computer. (This is why I'm looking into things like undervolting and ways to minimise heat and cpu fan speed/noise.) Too simplistic way of looking at it?

No, that nails it: less power -> less heat -> less cooling needed -> less noise.

Except when less heat means doing without the fan control you need to keep noise down.
So it might be good for noise to pick an Asus board even though they run hot.


The best way to achieve that is to spend less on the parts today and save the money. You'll soon be able to buy used parts to upgrade your computer for pennies on the dollar...
Buying a 1155 board that's compatible as many 1155 CPUs as possible means you'll have an easier time upgrading the CPU.


Your choice of 1155 CPU won't affect that. Today's average computer would use more power than yours even if you picked a quad-core down the road.

In order to keep heat and noise down, underclocking is sufficient unless you're planning to constanty crunch numbers with 100% of your CPU (it sounds like you're not). Underclocking in software is easy and reversible anytime in case you want to unlock your CPU's "computing reserve" for a particular task.
By the way, underclocking a quad-core gives you very good multi-threaded performance relative to the heat generated.

That's why I recommend not to waste your time and money on undervolting or the *T or *S CPUs.