Sandy Bridge 35W vs 65W vs 45W

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leandrodafontoura

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The main question: Is 35W really 35W?

Im in the process of getting a Sandy Bridge processor for a HTPC. Its function is only HDTV recording and playback. No games. As the case is ventiladed only by 3x 14cm fans, and I want to keep things silent, Im considering getting a 35W CPU. However, how really efective is that advertized TPD? I would be disapointed to get a 35W CPU, wich is relatively expensive, and find out that its working at 55W or something. Any articles, review on the matter?

Anyway, here are my options, they are all sandy bridge:

Pentium 35W http://www.newegg.com/Product/Product.aspx?Item=N82E16819116401
i7 Quad 45W http://www.newegg.com/Product/Product.aspx?Item=N82E16819111023
i5 Quad 65W http://www.newegg.com/Product/Product.aspx?Item=N82E16819115075


Im not not confortable with 65W, and the price for a 45 is insane, after all, I dont need an i7 in order to simply watch movies. the 35W seems a great choice, but is that TDP really 35W?
 
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Intel is very good about their TDP. Their TDP is based on the highest possible TDP under the highest possible load. Just as and example:

The QX9650 was rated for 130W TDP, yet at stock it was around 73W TDP:

47-chart_power_max.png


http://www.silentpcreview.com/forums/viewtopic.php?f=14&t=62636

That guy built a system just like what you want with the same CPU to do 1080P video playback and he states that the system hits about 35-40W total power consumption.

As I said, that TDP is rated for the maximum TDP you would see at the maximum load you can put on it. For what you want, that CPU will not even get near 35w TDP.

Intel is very good about their TDP. Their TDP is based on the highest possible TDP under the highest possible load. Just as and example:

The QX9650 was rated for 130W TDP, yet at stock it was around 73W TDP:

47-chart_power_max.png


http://www.silentpcreview.com/forums/viewtopic.php?f=14&t=62636

That guy built a system just like what you want with the same CPU to do 1080P video playback and he states that the system hits about 35-40W total power consumption.

As I said, that TDP is rated for the maximum TDP you would see at the maximum load you can put on it. For what you want, that CPU will not even get near 35w TDP.

 
Solution
TDP (thermal Design Power) is the maximum amount of power (heat) that the cooling system must be designed to dissipate. There are a number of ways to deal with this heat with active cooling being the most common. Just so you know there is other option in the Intel® Core™ i3-2100T which is also 35w processor.

Christian Wood
Intel Enthusiast Team
 

leandrodafontoura

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Yeah, in the 35W realm, there is a i5 as well, but since the i5 is not quadcore, and I dont care about hyperthreading, and the pentium is below $90, it seemed like the best choice for a hptc focused solely on watching media content.

I do feel atracted to the 45W i7 quadcore, but the $400 price is a turn down.
 

Technically, you are right. But it makes a reasonable high end estimate of the power consumption. Intel docs say the the TDP is power dissipated if every i/o pin on the CPU is used. And because of losses in the motherboard power regulator, it will probably come pretty close.

I have an OC'd Q6600 (stock TDP 90 watts). Based on actual measurements, at stock speed and voltage, it pulls 8 amps (96 watts from the PSU.

leandrodafont, it takes suprising like computer power to move video from a hard drive to a video screen. I was going to build a dedicated HTPC, but I found that the little WD TV Live does everything I need. The little box eats about 10 watts when it is running. Figure anoth 10 - 15 watts for a USB drive.
 
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