undervolting i7-4770/i5-4670

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laststop
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undervolting i7-4770/i5-4670

Post by laststop » Sun Aug 25, 2013 10:28 am

I just sold my corsair 550d build. Must give a big thanks to this site. Without the exhaustive testing and advice on this site it would of took a lot more money and time to get my system near silent.

Amazingly the Nanoxia deep silence 1 was actually in stock on newegg. Been wanting to get 1 for a long time. So I got a case sitting here, a pocket full of money from my previous pc sale and I'm back on spcr to make my buying choices efficient. On to my first question.

For my PC uses I really have no need to overclock. Games I play are gpu limited at stock speeds and basic computer tasks don't need an OC'd cpu. I do some transcoding that would benefit but it's not a big deal i can wait a few more mins for it to finish. Basically I would like to know how well these 2 chips undervolt. Will the i5 undervolt much better with a slightly lower clock and not HT? How will the temps of the 2 cpu's match up each at their max undervolt? I care more about the undervolting and temps then the slight speed increase of the 4770 but if the temps are going to be practically indistinguishable I'll go with the 4770. I don't need the K versions of these chips unless they are binned and will accept a better undervolt. Anyone have experience with this?


Edit: Just realized newegg has a combo deal for the Asus z87 expert + i7-4770k. Not small either a 55 dollar savings. Only 45 dollars extra over the i5 so I might as well go that route. Increases my resell value as well so it will potentially be a free upgrade after i sell and I move onto skylake. How is the success leaving i7-4770k at stock and undervolting? What's the lowest stable voltage I should get and how much does that lower the temps? Will they be low enough for a large passive heatsink?

CA_Steve
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Re: undervolting i7-4770/i5-4670

Post by CA_Steve » Sun Aug 25, 2013 12:09 pm

The limited information I've seen in reviews and message threads is that you can typically undervolt the i5 and i7 by 0.1V or more at stock clock. So, if your cpu runs at 1.08V stock, 0.98V implies (0.98^2)/(1.08^2) = ~82% of the wattage. So, 84W TDP becomes 69W.

In terms of temperature..if you saw a 50C rise for the stock voltage, the undervolt would roughly see a (.82*50) = 41C rise.

If you are lucky and can get down to 0.9V, then that 84W becomes 58W, and the 50C rise becomes 35C.

laststop
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Re: undervolting i7-4770/i5-4670

Post by laststop » Sun Aug 25, 2013 12:50 pm

Do you think I can get away with a fanless heatsink in a nanoxia deep silence 1 case with an undervolted chip?

CA_Steve
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Re: undervolting i7-4770/i5-4670

Post by CA_Steve » Sun Aug 25, 2013 1:55 pm

Maybe. Sorta depends on the cooler, case fans and whether or not you have a big wattage gfx card or other such stuff.

laststop
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Re: undervolting i7-4770/i5-4670

Post by laststop » Sun Aug 25, 2013 4:04 pm

I've read good things about the silverstone closed loop water cooler. That the pump is dead silent but the fans are noisy (which ill just replace the fans). Since I'm gonna have an msi gtx n780 TF the fanless heatsink probably wont work.

Vicotnik
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Re: undervolting i7-4770/i5-4670

Post by Vicotnik » Mon Aug 26, 2013 1:57 am

If silence is your goal you will better off with an air cooler. For overclocking water cooling is better, maybe.

Is that pump tested in the SPCR anechoic chamber? If not I suspect that "dead silent" means "I cannot hear it over the fans in my dual SLI setup". :p

And why even consider going passive on the CPU? That graphics card will be the source of the most noise for sure. The TDP is 250W if I'm not mistaken.

laststop
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Location: Youngstown, OH

Re: undervolting i7-4770/i5-4670

Post by laststop » Mon Aug 26, 2013 4:55 pm

I am going to experiment adding a fan on the side of the case to blow cold air directly on the GPU. May be quieter adding a low-medium low speed fan right on top of the card on the side panel allowing the gpu fans to spin slower. Wil also experiment with a fan on the bottom as additional intake to rly force positive pressure.

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