sandybridge question: mobile power use?

[gorobei]

in the market for a new tablet convertible notebook, the hp tm2t with i3 380um is available now, but according to some tabletPC forum users the battery life is worse than the older su7300.

Are the sandybridge mobile parts bringing any reduced power/batterylife gains or is it just cpu performance increase?

the i3 380 is listed as 18W tdp, but the anand preview lists i3 2100t as 35W tdp.

Performance, i know is better, but battery life is more important for me in this case.

 

[IGemini]

in the market for a new tablet convertible notebook, the hp tm2t with i3 380um is available now, but according to some tabletPC forum users the battery life is worse than the older su7300.

The SU7300 is a CULV processor that fits between Atom and mobile processors. It's an apples-to-oranges comparison of battery life, even with newer SB CPUs.

Are the sandybridge mobile parts bringing any reduced power/batterylife gains or is it just cpu performance increase?

Yes. Intel hasn't released any plans for CULV processors with Sandy Bridge yet.

the i3 380 is listed as 18W tdp, but the anand preview lists i3 2100t as 35W tdp.

Anand didn't list mobile processors, those were all for the desktop market.

http://en.wikipedia.org/wiki/Sandy_Bridge_(microarchitecture)#Mobile_processors

 

[gorobei]

The SU7300 is a CULV processor that fits between Atom and mobile processors. It's an apples-to-oranges comparison of battery life, even with newer SB CPUs.

yes but the only buying options for the 2010 tm2t is i3 380um or i5 470um. the 2009 had the su7200. if the 2011 version has sandybridge option, i need to figure out which one gives me the longest potential battery life.

Yes. Intel hasn't released any plans for CULV processors with Sandy Bridge yet.

Anand didn't list mobile processors, those were all for the desktop market.

http://en.wikipedia.org/wiki/Sandy_Bridge_(microarchitecture)#Mobile_processors

http://www.anandtech.com/show/3871/the-sandy-bridge-preview-three-wins-in-a-row
2nd table has low power versions data

 

[sxr7171]

I doubt they'll regress twice in a row. Surprised that they regressed once.

 

[IGemini]

http://www.anandtech.com/show/3871/the-sandy-bridge-preview-three-wins-in-a-row
2nd table has low power versions data

Yes, those are low power versions for desktops, like I said. Look at the link I gave AGAIN, it shows the mobile versions for upcoming SB (scroll up to see the low power desktop data). The 2100T is a desktop CPU, you won't see that in a tablet.

 

[IntelUser2000]

the i3 380 is listed as 18W tdp, but the anand preview lists i3 2100t as 35W tdp.

Performance, i know is better, but battery life is more important for me in this case.

First, I'll answer your question. Sandy Bridge should have bettery battery life than the Core ix based parts. Sandy Bridge should be released in "ULV" versions later next year with 17W TDP. At the moment its hard to say how it'll fare against the Core 2. You can ignore the i3 2100t as that's a desktop chip. The mobile chips all have the "M" suffix in their names.

Let's analyze this a bit.

Platform TDP figures:
SU7300:

10W CPU + 7W GMCH + 3.5W ICH = 20.5W total

i3/i5/i7 ULV

18W CPU + 3.5W PCH = 21.5W total

TDP-wise they should be identical. However there are key differences.

1. Core Duo vs Core 2 Duo: http://www.anandtech.com/show/2056/1

2. Core 2 Duo vs Core i5: http://www.anandtech.com/show/2902/3

Performance gain on the second comparison is significantly greater than the first one. But the first one didn't sacrifice battery life, while the 2nd one did.

My guess is that the Turbo Modes on mobile chips allow the Core i3/i5/i7 chips to reach TDP figures more consistently, while the older Core 2's generally were under TDP. The graphics unit and the CPU constantly balances frequency between each other and TDP is hit more often.

Core 2 vs Core Duo
Performance>
Battery life=

Core ix vs Core 2
Performance>>
Battery life<

 

[ydnas7]

SB was designed by Intel Haifa, and is obviously optimized for mobile applications.
as its from Intel Haifa, expect real world usability to be greater than the headline metrics would indicate.
remember TDP is not a measure of average energy usage but is a measure of cooling capacity required.

 

[sxr7171]

^^^ Exactly TDP is meaningless. I have used exclusively ultraportables starting with Thinkpad x31 to x200s and others. I can easily get about 6-8w consumption for regular browsing. Well getting 6w is hard but getting 8w is pretty easy if you set up the settings well.

But honestly now getting a Macbook Air it's clear OSX is far more power efficient and ideal for ultraportables. I mean 5-6 hour battery life in a 2.3lb machine was impossible before. There are 2.2lb Dell E4200 and 2.4lb X200s but to get that weight you need the ultra small battery and those give 3.5 hours maximum (if you are lucky). I get 5-6 easily with the Air. I bet if I bootcamp Win 7, that will drop to 3 hours. Basically MS is hindering ultraportables with their piss poor power management. Don't shoot the messenger.

 

[gorobei]

@inteluser: Thanks for the sum up. I had looked at some of the benches for the su and um series, but no one seems to be doing clear differentiation of power use. The main downside to core ix seemed to be the whole separate igp on die power drain, no clear measurements.

@sxr: the old su7300 HP tm2 vista/7 used to get 9 hours out of the battery regularly. mobile forum users indicate 7-8 hours real world at nominal loads. So windows isnt necessarily the problem.

@gemini: yes i know it is desktop but it is the only official thing i've seen recently. plus the wiki references semiaccurate.com for the data so there is some questionability to veracity until official data is released. better to go off of the official low power desktop figures till the mobile parts are released 2H'11 as far as i am concerned.

 

[Spikesoldier]

^^^ Exactly TDP is meaningless. I have used exclusively ultraportables starting with Thinkpad x31 to x200s and others. I can easily get about 6-8w consumption for regular browsing. Well getting 6w is hard but getting 8w is pretty easy if you set up the settings well.

But honestly now getting a Macbook Air it's clear OSX is far more power efficient and ideal for ultraportables. I mean 5-6 hour battery life in a 2.3lb machine was impossible before. There are 2.2lb Dell E4200 and 2.4lb X200s but to get that weight you need the ultra small battery and those give 3.5 hours maximum (if you are lucky). I get 5-6 easily with the Air. I bet if I bootcamp Win 7, that will drop to 3 hours. Basically MS is hindering ultraportables with their piss poor power management. Don't shoot the messenger.

The acer timeline (dont know about the timeline X) got eight hours off a full charge of the six cell battery. the unit has either single core SU2700 or SU3500. I think the MCH was a PM45. I would venture to say that claim of eight hours on a charge would increase to nine when you take the spinning disk out and put a ssd in.

acer does have some things in place to achieve that eight hours though, for example the unit turns off the optical drive when on battery power.

like i said im not sure about the current iteration, the timeline X, but the original timeline has been on my list for a long time.

 

[aigomorla]

Sandy Bridge will pwn all the laptops we currently know.

The ability to shift from IGP, to dedicated by a single driver is what will revolutionize the lap tops.

Disabling dedicated gpu's can extend your battery life by almost 20&#37;.
And the IGP is more then enough oomph to do what it needs to do in most 2d activities, to even light 3d activities.

But I am waiting for a SB laptop to upgrade.

 

[Riek]

Sandy Bridge will pwn all the laptops we currently know.

The ability to shift from IGP, to dedicated by a single driver is what will revolutionize the lap tops.

Disabling dedicated gpu's can extend your battery life by almost 20%.
And the IGP is more then enough oomph to do what it needs to do in most 2d activities, to even light 3d activities.

But I am waiting for a SB laptop to upgrade.

SB doesn't bring much new to the table for the lower power. They will sacrifice cpu power for better gpu performance. (ULV is rumored to be single core because of that). Maybe the idle power is better than the current i-M series, which i hope because otherwise it won't change the field (expect with gpu performance)