Intel’s Sandy Bridge i7-2820QM: Upheaval in the Mobile Landscape
by Jarred Walton on January 3, 2011 12:00 AM EST- Posted in
- Laptops
- Intel
- Sandy Bridge
- Compal
All the Performance, and Good Battery Life As Well!
We’ve just finished showing that CPU and GPU performance has basically more than doubled compared to last year’s Arrandale offerings. That’s great news, but what happens to battery life? We’ve got 35W TDP Arrandale parts compared to a 45W TDP Sandy Bridge quad-core; doesn’t that mean battery life will decrease by around 25%? The answer is happily no; as we’ve point out in the past, TDP isn’t really a useful measurement of power requirements. All the TDP represents in this case is the maximum amount of power Sandy Bridge should draw. So worst-case battery life under full load might drop, but the real question is going to be what happens under typical workloads.
Intel’s use of power gating and variable clock speeds is put to good use, with the result being battery life that is nothing short of exceptional when compared to previous generation products. We’ve seen ULV and Atom netbooks and ultraportables get battery life into the 8+ hour range, but such designs have always required serious compromise in the performance department. SNB certainly won’t beat out Atom for pure battery life, but that doesn’t mean it’s a power hog. Our Compal test system comes with a 71Wh battery, which is larger than what we’ve seen in many 15.6” and smaller designs but still reasonable for a 17.3” chassis. Here are the results of our standard battery life testing.
Yes, those figures are accurate. Best-case, running at 100nits, quad-core Sandy Bridge still lasted nearly eight hours on a single charge! What’s more interesting is that our standard Internet battery life test that loads four pages with Flash ads every sixty seconds still checks in just shy of seven hours. Finally, H.264 playback also comes in at the top of our charts, providing more than four hours of demanding video playback. If 240 minutes of content off your HDD/SSD isn’t enough, we also were able to watch a Blu-ray disc and still get 220 minutes of 35Mbit VLC playback. Wow!
So Sandy Bridge comes out on the top of the above charts, but we didn’t include some of the other long battery life alternatives. Just to put things in perspective, ASUS’ U30JC—with an SSD and an 84Wh battery—has long been our king for matching reasonable performance with long battery life. It managed 588 minutes idle, 476 minutes Internet, and 254 minutes H.264 playback. That’s 25% more idle life, but only 14% better Internet and actually slightly lower H.264 battery life, and you need to factor in the 18% higher capacity battery and 13.3” (versus 17.3”) LCD.
We have to wonder just how small of a form factor manufacturers can manage to cram the quad-core Sandy Bridge into. Idle and low usage power requirements are clearly very good, but with maximum TDP still at 45W the chassis needs to be able to handle the heat. We’d really love to see some 14” designs with quad-core CPUs, and the icing on the cake would be sticking a reasonably fast discrete GPU with graphics switching technology into the case as well. Intel doesn’t have any LV/ULV quad-core parts listed—yet!—so we may have to wait for ultraportable quad-core laptops, but certainly 15.6” designs should be able to combine SNB with reasonably fast Optimus GPUs to provide an optimal blend of performance and mobility.
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JarredWalton - Monday, January 3, 2011 - link
True, it's been around a while, but I found it interesting that while performance dropped, it wasn't the "slideshow effect". If the system sat idle, the CPU would start to cool down, so when I fired up a benchmark it would run fast for a little bit. It was very perplexing until I figured out what was happening. First run on MediaEspresso gave me 11s with Quick Sync. Then I ran it again and it was 17s. The next time it was suddenly down to 33s.QChronoD - Monday, January 3, 2011 - link
I'm hoping that someone will annouce something like ASUS's new U36JC that has an i5-2410 at CES. I'd love to be able to go a full day at school without needing to recharge in almost every class (and actaully be able to play minecraft between classes)PlasmaBomb - Monday, January 3, 2011 - link
That should read the GTX465 comes next...
PlasmaBomb - Monday, January 3, 2011 - link
To correct the correction (I was going by the graphs), the graphs for the G73J should read GTX460M (I noticed the reference to the GTX460M in the text later and checked the G73J article).God help us all when it comes to talking/writing about the Sandy Bridge chips themselves, "the i7-2539"...
JarredWalton - Monday, January 3, 2011 - link
Fixed, thanks. I had some good ones in those graphs... G73Jw with 260M and 456M, but no 460M! LOLiwodo - Monday, January 3, 2011 - link
now all that is left are Gfx drivers, i hope intel put 10x more resources at their current Gfx Drivers team.Other then that, i am waiting for Ivy Bridge........
ET - Monday, January 3, 2011 - link
I imagine that a single resolution is the best way to compare different machines, but it would have been nice to see some gaming benchmarks at the native res. 1600x900 is not a whole lot higher than 1366x768 (37% more pixels), so I imagine it's possible to game with low details at that resolution. Many Anandtech articles add such figures into the benchmark tables, and I was really missing them here.JarredWalton - Monday, January 3, 2011 - link
I ran out of time, but I did test 1600x900 at our "High" defaults. Umm... not really what you'd want, as everything is completely unplayable. Perhaps post-CES I'll get a chance to do additional testing, but my feeling is most actual notebooks using SNB will likely ship with a 768p display. Some might do 1080p as well, but they'll be more likely to include Optimus GPUs for gaming.therealnickdanger - Tuesday, January 4, 2011 - link
Good idea testing at 1366x768. Not only does it fall in line with most notebook screen resolutions, but it also give good indication of 720p performance. Given that many, many gamers play PS3 and 360 (most games being 720p@30fps), it's very good to see that most games are completely playable from low-medium settings. Some games could probably even get away with higher settings and still stay around 30fps.It's awesome that Intel is putting the "HD 3000" GPU in all its mobile chips, but I'm very curious how the different clock speeds of the GPU and CPUs will affect performance.
ULV Sandy Bridge numbers soon?
therealnickdanger - Tuesday, January 4, 2011 - link
Oh yeah, I forgot to add:What's with Dark Athena? Is it really that stressful to run or is there a driver issue?