XPS Sandy Bridge Battery Life

One thing that many people are interested in when deciding between dual core and quad core is whether there are any battery life differences between them. As far as I've seen, there haven't been any direct reviews comparing the processors in these terms.



So I was thinking it would be useful for people to post their model (15 or 17), processor model number, RAM amount, graphics card (and say if you overclocked it), and battery size, and then report the results of the following:



Set to Balanced power management with 50% brightness and, while on AC power, set the computer up for its power usage (e.g. start Prime95 running), then take it off AC power, continue the task for 5 min, then divide the estimated time remaining by the percent power remaining (e.g. 1.5 hours with 90% remaining: 1.5 / 0.9 = 1.67 hours). This will give you the total projected battery life if you were to continue that task until the battery was drained.



The useful test conditions, I think, would be:

1) Screen on but no applications running.

2) Browser open playing a standard def YouTube video

3) Prime95 (full CPU load)

4) Prime95 + Furmark (full CPU + GPU load)



Of course it would be better to actually run out the battery doing these things, but these quick tests are easier and should give a good indication of the differences between the processors and other components.



Because of the power-gating, I would generally expect that for the same other components, the battery life in conditions 1 and 2 would be largely the same, but that for 3 and 4, the quad cores would have worse battery life. I might also expect more RAM and a higher-clocked GPU to also lead to worse battery life. But I think people would benefit by finding this out.



EDIT: Oh, and say if you are using the wireless card.

Reply 1 : XPS Sandy Bridge Battery Life

This might be a good idea. I'm going against prime95, as it is unrealistic in terms of power usage and the fact that it can take advantage of all 8 threads on a quad core vs 4 threads on a dual core, so there will be a big difference in battery life that doesn't equate to real world scenarios. I can't remember who did this, but something like playing a blue-ray movie and checking the percentage left afterwards would be entertainment and more accurate as well as realistic to how we actually use the laptops. Playing a blue-ray probably won't enable the nvidia gpu. I've also noticed through the many 3dmark06 tests I've run, that without the AC power hooked up, my scores are around 25% lower, leading me to believe that the gpu isn't enabled on battery power, or some other battery saving function is specifically hindering performance to save on battery life. This should be addressed before any cpu or gpu intensive tasks are benchmarked for the purpose of checking battery life.