Need power efficient intel..

[v8envy]

My i7 920 runs at .92 volts at stock speed. While on a burning pig of an inefficient chipset that does soften the blow when I get the power bill at the end of the month.

In reality my power bills are unchanged since I replaced a 3.2 @ ghz @1.3v E2180 with a 3.8 ghz @ 1.1v 920 (the rest of the box remained the same) -- mostly because the speedstep implementation in the i7 seems to work and work very well. My usage patterns are very similar to yours -- I do more compiling than transcoding though. The machine gets done faster and idles faster, and overall winds up using less juice.

You'll be more than fine with a stock clocked 860.

 

[ElFenix]

if power is that big of a deal, the 750, 860, and 870 are your best bets for a combination of power consumption and performance. consumption for each of those at idle is a good 30 watts lower than the 920. the 860 tends to be a tad quicker than the 920 at everything, so it'll also be at peak power consumption less than the 920 (and it's about 20 watts lower while at it, as well). yes, it uses significantly more power than the 670 (32nm dual core) when at load, but it can also accomplish tasks significantly faster (nearly twice as fast at x264 recode, for example). so, power consumption is basically a wash there, but time consumption is much lower.

i'd also toss in 8GB of ram if you can afford it.

860 can use P55, H55, and H57 motherboards. they tend to be less expensive than the X58 boards required by the 920. frankly more ram sounds more useful than a theoretical upgrade path in the future.


dvd burning isn't a heavy load.

 

[talonz]

The primary features of i7 that are attractive to me are HT and turbo boost which are missing in i5. I like turbo boost for the same reason I liked AMD64 cool n quit feature when I bought it. I prefer variable speed based on workload. So ability to underclock when not in use or overclock when needed is nice. I wonder if you can shut off cores?

The i5 750 does have turbo boost and actually has a better implementation of it than the i7 920.

http://www.anandtech.com/show/2832/5

Take a look here for additional power/performance charts and you may end up choosing the i5 750, I did. (Look at task energy and total energy over period when comparing the i5 750 and the i7 870)

http://techreport.com/articles.x/18448/4

http://techreport.com/articles.x/18448/17

 

[taltamir]

since you upgrade infrequently, I say get 1366 i7 920. It will allow a jump to 6core for you later when you need more processor power.

intel is showing no indication of ever releasing a sub 1000$ hex core for the s1366... if you want affordable hex core you are going to have to wait for sandy bridge which is NOT compatible with any of the current sockets.

Hyperthreading's impact on performance-to-power ratio is a bit difficult to estimate, but the thing you need to remember is that HT does nothing but put additional load on "real" cores by creating "fake" cores to handle additional threads. In other words, the power consumption that comes from enabling and fully utilizing HT is based on the physical core that is taking on the additional load.

the core performs calculations in steps, called a "pipline". The more steps you have, the longer your pipeline. HT moves two instructions along these at the same time and can result in some hardware that is not being utilized due to the nature of the current instructions to get utilized more and get better performance.
results? depending on the exact mathematical formula being computed, enabling HT can result from anywhere between a 5% DECREASE in speed to an 80% INCREASE in speed. (with a small increase in power consumption)... resulting in either a decrease or an increase in power efficiency depending on the type of calculations you are performing.

If I remember correctly, HT gives a significant speed and power efficiency boost to video editing. but you will have to look into detailed reviews that test the increase in performance with it on and off for various known tasks. (or you can perform said tests yourself, since you can turn off HT on any HT enabled processor).

 

[capita]

If I remember correctly, HT gives a significant speed and power efficiency boost to video editing. but you will have to look into detailed reviews that test the increase in performance with it on and off for various known tasks. (or you can perform said tests yourself, since you can turn off HT on any HT enabled processor).

Thats what I am thinking. Because back in AMD64 vs P4 days it was about x64 of AMD vs HT of Intel when it came to tech features. Video editing and 3d rendering were one of the only things that benefited from HT.

 

[capita]

it uses significantly more power than the 670 (32nm dual core)

ammm 670? which cpu is that?

 

[capita]

Oh I just figured out that there are two types of i5, 6xx and 7xx. 6xx are dual cores with HT and 7xx are quad cores without HT?

which one is newer?

I can't find 6xx i5 in local market. So are they newer?

 

[capita]

The i5 750 does have turbo boost and actually has a better implementation of it than the i7 920.

http://www.anandtech.com/show/2832/5

Take a look here for additional power/performance charts and you may end up choosing the i5 750, I did. (Look at task energy and total energy over period when comparing the i5 750 and the i7 870)

http://techreport.com/articles.x/18448/4

http://techreport.com/articles.x/18448/17

Thats nice. Maybe its the i3s that don't have?

gonna check the links

 

[ElFenix]

Oh I just figured out that there are two types of i5, 6xx and 7xx. 6xx are dual cores with HT and 7xx are quad cores without HT?

which one is newer?

I can't find 6xx i5 in local market. So are they newer?

yeah, the 6xx is newer. the 6xx and 5xx processors are all dual core HT enabled 32 nm processors. the 7xx processor is a quad core no-HT 45 nm, and everything above that is quad core 45 nm HT enabled (with the exception of the 980X). the 9xx processors all run on the x58 chipset, but with the lower clockspeed versions there is little benefit to the added memory bandwidth of tri-channel. the benefit of x58 is that it *may* provide an upgrade path and it is better for running SLI/crossfire. downside is that boards tend to be significantly more expensive

 

[capita]

http://techreport.com/articles.x/18448/4

How does dual core i3 530 consumes more power then quad core i5 570 at idle? Granted its clocked a bit higher but still. Shouldn't 2 more cores require alot more power then few mhz? Does it has something to do with motherboard?

Considering this i3 is out of the picture.
920 is also out of the picture. Both idle and peak are above my liking.

I am almost considering i5 750. Great idle consumption with digestable peak. Although a little lower would have been great. I wonder if their peak wattage was measured with turbo boost running?

870 idle looks great too. Peak is just a little above my liking. I can't find 870 in my local market. Have they just been released?


There is no mention of 860 in the charts. Wonder why?

 

[DrMrLordX]

I just came from market. The h55tc intel mobo that comes with i3 530 costs about the same as the DP55WB intel they paired with i5 750. Around $100 each. Not saying I am gonna buy the mobo they paired, but seeing that I thought the prices of mobo for i3 and i5 are around same?

Depends on how much you shop around. There are H55 mobos around for as little as $55 online, but some of those are refurbs. The cheapest non-refurb I can find is at Amazon for $78 + free shipping: http://www.amazon.com/Biostar-Intel-.../dp/B003A4H4P2

$100 for a P55 board is not a bad deal, and if it does what you need it to do, then you aren't getting much from going H55.

Isn't there any i5 based on 32nm? I thought the new i3 , i5 and i7 processors were all based on 32nm. T

This is where Intel's processor naming scheme gets confusing. There are 32nm i5s, but they are dual-core Clarksdales that cost too much for what they do. The quad-core i5-750 is a 45nm Lynnfield. But you seem to have figured that part out.

The 860 and 920 are costing me exactly same. Although 860 is not readily available. What about 860 mobos?

The i7-860 is an LGA1156 processor (Lynnfield) that would use the same motherboard as an i5-750 or even an i3-530. You can think of it as a 750 + Hyperthreading.

the core performs calculations in steps, called a "pipline". The more steps you have, the longer your pipeline. HT moves two instructions along these at the same time and can result in some hardware that is not being utilized due to the nature of the current instructions to get utilized more and get better performance.
results? depending on the exact mathematical formula being computed, enabling HT can result from anywhere between a 5% DECREASE in speed to an 80% INCREASE in speed. (with a small increase in power consumption)... resulting in either a decrease or an increase in power efficiency depending on the type of calculations you are performing.

If I remember correctly, HT gives a significant speed and power efficiency boost to video editing. but you will have to look into detailed reviews that test the increase in performance with it on and off for various known tasks. (or you can perform said tests yourself, since you can turn off HT on any HT enabled processor).

Yes, that is a good description of what HT does. I was simply alluding to the fact that a HT-created logical processor handling a thread on a Clarksdale would probably use less power doing so than an HT-created logical processor handling the same thread on a Bloomfield.

http://techreport.com/articles.x/18448/4

How does dual core i3 530 consumes more power then quad core i5 570 at idle? Granted its clocked a bit higher but still. Shouldn't 2 more cores require alot more power then few mhz? Does it has something to do with motherboard?

If the test was fair, techreport should have been running the i5-750 on the same board as the i3-530. That being said, it could have something to do with how aggressive power-saving features are on the i5-750 vs. the i3-530. The 750 may also benefit more from power-gating but I'm not sure about that. Considering the difference is 4W, it doesn't seem like a big deal.

Considering this i3 is out of the picture.
920 is also out of the picture. Both idle and peak are above my liking.

Yeah, I figured you'd want a quad. Hell initially I figured you'd need a quad with HT, but now that you have described your usage patterns a bit more, maybe not so much. In that case an undervolted i5-750 should fit the bill. I only threw Clarksdale out there because they can be really efficient chips (just a bit underpowered).

I am almost considering i5 750. Great idle consumption with digestable peak. Although a little lower would have been great. I wonder if their peak wattage was measured with turbo boost running?

Probably, though you can always disable turbo. And undervolt.

870 idle looks great too. Peak is just a little above my liking. I can't find 870 in my local market. Have they just been released?

The i5-750, i7-860, and i7-870 were all released at about the same time.

There is no mention of 860 in the charts. Wonder why?

For whatever reason, some reviewers did not review this chip in their first batch of Lynnfields, and still others never reviewed it at all. Anandtech had to do an i7-860 followup article to supplement their initial Lynnfield release article: http://www.anandtech.com/show/2839

 

[pm]

For what it's worth, my Core i7 920 w/ Asus P6T, 4GB DDR3, 2x1TB HD and ATI 5770 video card pulls 101W from the wall idling (using Asus's EPU-6 Engine to put it in a lower freq/volt mode).

 

[dualsmp]

http://techreport.com/articles.x/18448/4

How does dual core i3 530 consumes more power then quad core i5 570 at idle? Granted its clocked a bit higher but still. Shouldn't 2 more cores require alot more power then few mhz? Does it has something to do with motherboard?

Considering this i3 is out of the picture.
920 is also out of the picture. Both idle and peak are above my liking.

I am almost considering i5 750. Great idle consumption with digestable peak. Although a little lower would have been great. I wonder if their peak wattage was measured with turbo boost running?

870 idle looks great too. Peak is just a little above my liking. I can't find 870 in my local market. Have they just been released?


There is no mention of 860 in the charts. Wonder why?

I saw that as well but it doesn't jive with any other review I've seen. I can tell you this that my i3 530 idles at 32w with integrated graphics, and if I had a more efficient power supply the power consumption would dip into the 20's. If you need a quadcore the the i5 750 is hard to beat as it's a very efficient chip for a quad.

 

[Spicedaddy]

dual: Core i3 530
quad: Core i5 750

The OS also plays a part in power consumption, I'd go with Windows 7.

 

[Ksyder]

capita you may want to take a look at this:

http://www.tomshardware.com/reviews/25w-performance-pc,2551.html

 

[taltamir]

it is interesting to note that even the intel ATOM uses hyperthreading.
http://en.wikipedia.org/wiki/Intel_Atom

hyperthreading gives you such good performance per watt that the atom dropped out of order execution but kept HT\

EDIT: this took me literally forever to find... for some reason i can't find any benchmarks of atom even though i remember seeing them all over the web...
anyways, enjoy:
http://xtreview.com/addcomment-id-4801-view-Intel-atom-1.6-Ghz-benchmark.html

noticed that they compare it with HT-on and HT-off and see how massively better it performs with HT-on

 

[capita]

My head is spinning from the amount of reading I've been doing for past few days.

Here is more confusion:

http://anandtech.com/show/2832/17

i5-750 consumes 184w at load! More then i7-870 at load in the same bench? How is that possible?

The idle readings are almost exactly the same as that by techreport for 750 and 870. But the load readings don't look right.

Am I missing something here?

 

[capita]

I saw that as well but it doesn't jive with any other review I've seen. I can tell you this that my i3 530 idles at 32w with integrated graphics, and if I had a more efficient power supply the power consumption would dip into the 20's. If you need a quadcore the the i5 750 is hard to beat as it's a very efficient chip for a quad.

With use of integrated graphics it would go very low ofcourse. But it will be comparing apple to oranges. It can only be compared to i5 6xx series with integrated graphics.

But I will be using 5770 graphics card so integrated graphics that comes with the new series doesn't concern me.

But this may explain the weirdness of i3-530 idling at higher power consumption then i5-750. Maybe its because of the integrated graphics ?
Maybe even if its not in use it contributes to power consumption?

 

[capita]

But I just remembered. The i3 530 has smaller die then i5-750. That makes it even more weird.
Maybe the clock speed has alot more to do with power usage at idle then cores. Which reminds me.

Since I have been reading I found out that when a i5 and i7 are only using 2 cores the other 2 cores are almost shut off with very less power leakage compared to older processors. Intel is calling it power gate transistor or something.

Maybe its so efficient that at idle at i5-750 is basically a dual core and those 2 cores are lower clocked then i3 530's so it eats less power? Even with a bigger die?

That will be so cool if true.

Update:
I think i5-750 can power off all 3 cores when not in used? If so then i3-530 can probably shut down one of its core. Which may mean its basically core vs core at idle

 

[capita]

capita you may want to take a look at this:

http://www.tomshardware.com/reviews/25w-performance-pc,2551.html

Very interesting stuff. Specially with regards to power supply. I already knew I have to do some brainstorming on which psu to get for my system. But this has raised the bar alot more.

I am wondering though. If peak power usage of a system is say 250 watts. Does this mean a PSU with 350 max output is adequate?

 

[capita]

For what it's worth, my Core i7 920 w/ Asus P6T, 4GB DDR3, 2x1TB HD and ATI 5770 video card pulls 101W from the wall idling (using Asus's EPU-6 Engine to put it in a lower freq/volt mode).

Interesting. How much at peak load? Do you ever feel that 4 GB aren't enough? By the way, how much these power wattage readers cost?

 

[capita]

For whatever reason, some reviewers did not review this chip in their first batch of Lynnfields, and still others never reviewed it at all. Anandtech had to do an i7-860 followup article to supplement their initial Lynnfield release article: http://www.anandtech.com/show/2839

Performance wise 860 is very close to 870. Both are 4 cores with HT and turbo boost. The only difference I can find is about 130 Mhz in clock speed and slightly better turbo boost.

But it costs twice as much. Whats the deal?

 

[aamsel]

ttt

 

[pm]

Interesting. How much at peak load? Do you ever feel that 4 GB aren't enough? By the way, how much these power wattage readers cost?

No, I've honestly never felt that 4GB is not enough. About the only time that I come close to using 4GB is when I have more than one virtual OS running at the same time - which I've only done a couple of times when doing compiler experiments on code. The rest of the time, I would think that 2GB would be enough.

I was doing experiments, and found that with a few more tweaks I can get down to 99W idling.

My watt meter was a present from my wife for Christmas. But I saw one at Radio Shack the other day for $25.

 

[pm]

Interesting. How much at peak load? Do you ever feel that 4 GB aren't enough? By the way, how much these power wattage readers cost?

No, I've honestly never felt that 4GB is not enough. About the only time that I come close to using 4GB is when I have more than one virtual OS running at the same time - which I've only done a couple of times when doing compiler experiments on code. The rest of the time, I would think that 2GB would be enough.

I was doing experiments, and found that with a few more tweaks I can get down to 99W idling. It's a bit hard to see in the photo, but it's reading 99W.

I'm not actually sure how to go about coming up with peak load... I'll try some things and will post back.

My watt meter was a present from my wife for Christmas. But I saw one at Radio Shack the other day for $25.