Ivy bridge i5 vs i7 power consumption

[marcplante]

I'm looking at a notebook for my wife. Asus N56, which is avaiable with either and i7 or an i5 processor. are there any significant battery life distinctions between the two when doing general surfing. Will the power management in the i7 step down to conserve when it doesn't have a lot to do?

I'd like to leave headroom for my wife to use the computer for several years, but if I can get a benefit of at least 10% in battery life for the notebook, it would be worth it.

Thanks,

 

[ShintaiDK]

As in idle? Then there is basicly no difference between the 2.

Changing the HD to SSD, if it doesnt already have an SSD would yield much greater results for example.

 

[sm625]

We have no idea which i5 or i7 you are talking about. It could be a 17W i7 vs a 35W i5. In that case the i7 would use less, but not that much less.

The power management of both chips is such that you will not notice a difference in performance or battery life between the two during general web surfing, youtube, netflix, etc. (Not including flash games) With flash games a 17W chip will use a lot less battery since flash games often will push a core up to max turbo.

 

[marcplante]

Thx. I'll check the wattach on the chips available. SSD is an update plan, though I'd like to hold off until the holiday season to see if the 240G models drop comfortably below the $200 mark

 

[ShintaiDK]

Thx. I'll check the wattach on the chips available. SSD is an update plan, though I'd like to hold off until the holiday season to see if the 240G models drop comfortably below the $200 mark

Friend of mine got a 256GB M4 for 165$ on a sale.

 

[cantholdanymore]

Make sure you can upgrade to ssd later; some vendors may not give you that option in their bios

 

[ThatsABigOne]

Make sure you can upgrade to ssd later; some vendors may not give you that option in their bios

First time hearing of that? Source?

 

[ShintaiDK]

Make sure you can upgrade to ssd later; some vendors may not give you that option in their bios

So they cant upgrade HDs either?

 

[cantholdanymore]

So they cant upgrade HDs either?

Oh boy! I've should've known better
For better support your SSD you'll need AHCI mode. That your vendor may decide to castrate if you don't buy the SSD from them.

 

[ShintaiDK]

Oh boy! I've should've known better
For better support your SSD you'll need AHCI mode. That your vendor may decide to castrate if you don't buy the SSD from them.

SSDs work just fine with IDE mode. TRIM is just the icing on the cake.

But the vendor cant castrate AHCI, unless they did it from the start with HDs too.

I have never seen or heard anything like that before.

 

[pantsaregood]

SSDs work just fine with IDE mode. TRIM is just the icing on the cake.

But the vendor cant castrate AHCI, unless they did it from the start with HDs too.

I have never seen or heard anything like that before.

Some OEMs hide pretty much every option in the BIOS other than date and time. My laptop supports AHCI, but I had to mod the BIOS to actually enable it.

 

[2is]

SSDs work just fine with IDE mode. TRIM is just the icing on the cake.

But the vendor cant castrate AHCI, unless they did it from the start with HDs too.

I have never seen or heard anything like that before.

HDD's don't really see much benefit from AHCI though, and often times even peform better in IDE mode. But I agree that it should work fine in IDE mode, provided the SSD has good garbage collection to make up for the lack of TRIM.

 

[marcplante]

To get the thread back on track with more specific information, the processors in question are on two variants of an Asus N56. They are:

Intel® Core(tm) i7-3610QM

Intel® Core(tm) i5-3210M

Can anybody point me to power consumption benchmarks? If I can get an extra 20-30 mins out of a rated 4 hr stock battery for my wife's evening couch surfing. It'd be worth the proc downgrade. Otherwise, I'd stick with the quad core to cuture proof.

Thanks,

 

[ShintaiDK]

I would get the i5. Even for long term future.

The quadcore will essentially only use more power when loaded more. Else its almost insignificant more due to gating.

 

[ChippyUK]

http://www.notebookcheck.net/In-Review-Intel-Ivy-Bridge-Dual-Core-CPUs.75342.0.html

Towards the bottom of the page is a graph, it doesn't have the i5-3210M on it but it's going to be very similar to the i5-3320M.

So as stated by everyone the differences are small but favor the i5 slightly. I guess you'll have to make do with 30mins of extra nagging b4 bed.

 

[marcplante]

Perfect. So under normal conditions, its a wash. You "pay" for the i7 when you need it. Pretty good engineering...

Thanks for finding the benchmark.

 

[GoSharks]

HDD's don't really see much benefit from AHCI though, and often times even peform better in IDE mode. But I agree that it should work fine in IDE mode, provided the SSD has good garbage collection to make up for the lack of TRIM.

SSDs work just fine with IDE mode. TRIM is just the icing on the cake.

Oh boy! I've should've known better
For better support your SSD you'll need AHCI mode. That your vendor may decide to castrate if you don't buy the SSD from them.

TRIM is not specifically related to AHCI.

The TRIM command is dependent on the SSD itself, and the operating system supporting it. It is not dependent on the host controller, and AHCI is not a requirement.
http://forum-en.msi.com/faq/article/ide-sata-and-ahci-all-you-need-to-know

 

[ShintaiDK]

Ye, but assuming Windows Vista/7. Then it requires the MSAHCI. That toolboxes etc can do it manually is another matter.

 

[Christobevii3]

Sandisk 256GB for $140 after rebate. http://www.buy.com/prod/kingston-ssd...226050640.html

 

[Fjodor2001]

The quadcore will essentially only use more power when loaded more. Else its almost insignificant more due to gating.

This is what I've heard too.

One thing I wonder though - how come there are special 17W TDP Ultrabook versions of IB? Wouldn't you be better off just getting a mobile Quad core with higher frequency and TDP, and rely on power gating to cut power consumption when the additional cores are not needed (and similarly to rely on frequency scaling)? Or is there some other reason that the 17W TDP versions of IB provides longer battery life (assuming they actually do)?

 

[ShintaiDK]

This is what I've heard too.

One thing I wonder though - how come there are special 17W TDP Ultrabook versions of IB? Wouldn't you be better off just getting a mobile Quad core with higher frequency and TDP, and rely on power gating to cut power consumption when the additional cores are not needed (and similarly to rely on frequency scaling)? Or is there some other reason that the 17W TDP versions of IB provides longer battery life (assuming they actually do)?

No. TDP also points to the maximum cooling solution. Same reason we got 3770T and S models too. TDP means Thermal Design Power.

17W dualcore would also be faster in 2 threads than a 17W quadcore would ever be, even with gating.

When I almost insignificantly. It doesnt mean it uses 0. Plus the TDP issue again.

 

[Magic Carpet]

I'm looking at a notebook for my wife. Asus N56, which is avaiable with either and i7 or an i5 processor. are there any significant battery life distinctions between the two when doing general surfing. Will the power management in the i7 step down to conserve when it doesn't have a lot to do?

I'd like to leave headroom for my wife to use the computer for several years, but if I can get a benefit of at least 10% in battery life for the notebook, it would be worth it.

Thanks,

10% battery time, is it worth it? Why not just upgrade to a bigger capacity battery instead.

i5 should be better for general use otherwise, due to higher clocks and less heat output.

 

[Fjodor2001]

No. TDP also points to the maximum cooling solution. Same reason we got 3770T and S models too. TDP means Thermal Design Power.

17W dualcore would also be faster in 2 threads than a 17W quadcore would ever be, even with gating.

When I almost insignificantly. It doesnt mean it uses 0. Plus the TDP issue again.

You brought up some other valid points. But my main focus was on battery life.

So the question still remains: Will a 35/45W TDP IB CPU (quad core, higher max frequency) have as long battery life as a 17W TDP IB CPU (dual core, lower max frequency)? If not, why?

 

[GoSharks]

Ye, but assuming Windows Vista/7. Then it requires the MSAHCI.

No, it doesn't.

From somebody speaking in an official capacity:

To enable TRIM in Windows 7 do I need to be in AHCI mode? Or does it also work in IDE Native mode as well?

IDE and AHCI
http://www.ocztechnologyforum.com/f...RIM-in-W7-AHCI&p=444817&viewfull=1#post444817

 

[ShintaiDK]

You brought up some other valid points. But my main focus was on battery life.

So the question still remains: Will a 35/45W TDP IB CPU (quad core, higher max frequency) have as long battery life as a 17W TDP IB CPU (dual core, lower max frequency)? If not, why?

No it wont. And question already answered. Not to mention the U series are ULV parts.