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Intel i7 4790T: Is this the greatest performance VS watt CPU?

Boomstick777

Boomstick777

Boomstick777

Soldato
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Looking for a very low power consumption CPU that can still pack a punch. Some of Intel's best aren't commercial available for the consumer even at OEM. Out of the ones that are the i7 4790T stands out, a 45W CPU that has performance around 3770K level 4 core / 8 threads. Performance to watt ratio is mind blowing.

Would consider a Xeon chip, needs to have 4 core / 8 threads, is there anything better than this chip at a similar or better price level (£220)?

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45W !! :eek:

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really good if your not an overclocker

I wonder how much a downclocked (2.7ghz) 3770k would use though? trouble is it wouldn't be as fast clock for clock
 
wazza300 said:
really good if your not an overclocker

I wonder how much a downclocked (2.7ghz) 3770k would use though? trouble is it wouldn't be as fast clock for clock
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Yeah that's what I'm thinking, this build isn't for overclocking. I've read these 'T' chips are heavily power optimized and binned for low power consumption, so I would prefer a low power CPU rather than down-clocking a higher end CPU.

If anybody can beat this chip, let me know? So far this is the one I'm looking at, would be happy to consider a Xeon alternative as well, preferably on H97 / Z97 chipset.

Cheers guys.
 
Have you considered the standard i7 4790, then under volting it?

I have a standard i7 4770 powering a server that's under volted by quite a margin, I expect it's not drawing much more then a i7 4770T at peak, plus it's a little quicker.

Then again if you wanted super low power you could get the T version of chip and under volt that!

EDIT: Looking at passmark for i7 4790T. Passmark has some single threaded performance tests. To reduce wattage the i7 4790T clocks back when all 4 cores in use, 1-2 core it's still very quick however. I expect if you benched the i7 4790T against something using all 4 cores it would show quite a bit slower then a standard i7 4790. For general windows usage the i7 4790T is fine, but anything that's loading 4 cores performance will suffer.
 
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JasonM said:
Have you considered the standard i7 4790, then under volting it?

I have a standard i7 4770 powering a server that's under volted by quite a margin, I expect it's not drawing much more then a i7 4770T at peak, plus it's a little quicker.

Then again if you wanted super low power you could get the T version of chip and under volt that!

EDIT: Looking at passmark for i7 4790T. Passmark has some single threaded performance tests. To reduce wattage the i7 4790T clocks back when all 4 cores in use, 1-2 core it's still very quick however. I expect if you benched the i7 4790T against something using all 4 cores it would show quite a bit slower then a standard i7 4790. For general windows usage the i7 4790T is fine, but anything that's loading 4 cores performance will suffer.
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Yeah it's a good point you're making, the more I looked into it, it seems the power savings can be moot as it can take longer to complete a given task, i.e a higher clocked CPU may use more power at full load but spend less time completing a task and thus still use less power. It actually makes the AMD chips look truly awful as load power consumption is much higher than Intel and a given task can also take twice as long, so the AMD chips really are seriously power hungry.

Having looked at the different chips, the i7 4790S (65W) seems the best one for a low power small form factor build, the max turbo is 4GHz, the chip is optimized and binned for lower power consumption. Because it can clock high it completes tasks quickly and uses less power while doing it.

Compare the 4790S to something like a FX 8320E, and not only is the working power consumption lower but completes task in half the time, meaning AMD have nothing to offer as an alternative.

i7 4790S the chip I will put into this build.

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If it's power saving (and heat) your trying to save, it's very important you get a very stable PSU. The more stable PSU, the more you can under volt. Otherwise the i7 4790S looks a good compromise between watt and processor performance.
 
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Well from what I gather the Phenom II and FX CPUs can be undervolted a decent amount anyway and to a lesser degree the Intel chips(which seem closer to their ideal voltages).

Ultimately I would not bother with the S and T series chips anyway - under sustained load they will tend to not boost anywhere as highly and I suspect a normal Core i7 might not be far off in effiency anyway especially if you undervolt it a bit.

I have had both the SB and IB Xeon E3 chips in quite cramped cases,and they have been mostly fine,and that is coming from someone who only uses SFF systems primarily from 2005 onwards.

In fact the only ULV Intel desktop chips which I find interesting are these:

http://ark.intel.com/products/75053/Intel-Xeon-Processor-E3-1230L-v3-8M-Cache-1_80-GHz
http://ark.intel.com/products/65735/Intel-Xeon-Processor-E3-1220L-v2-3M-Cache-2_30-GHz

They are very low TDP and could make an alternative to an APU, with something like a low power card, in a DC-DC PSU powered system but OFC at a much higher outlay than an APU.
 
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CAT-THE-FIFTH said:
Well from what I gather the Phenom II and FX CPUs can be undervolted a decent amount anyway and to a lesser degree the Intel chips(which seem closer to their ideal voltages).
Click to expand...

I have an i7 4770k overclocked to 4.1 that idles at 0.653, it's had 0.065v reduced in bios (thats undervolting + overclocking!). I also have a server with a standard i7 4770 (non K) that's undervolted by more, but can't remember how much without checking. I use Seasonic X Gold PSU's everywhere (own 4 currently) and convinced they help undervolting due to stability.

EDIT Just remote logged into server running stock i7, thats running at 0.624v idle so I must have undervolted by around 0.09v.
 
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