Dell XPS 15 Haswell Edition: QHD+ with a Refined Design
by Jarred Walton on March 6, 2014 7:00 AM ESTDell XPS 15: Battery Life
Our final set of tests is for battery life, and here again we have a change or two to make. I did run our 2013 battery tests, but for 2014 I’ve made some changes. First, our “Heavy” test will now use the Windows Video app to play back a 1080p MP4 movie – the use of MKV files basically resulted in lower battery life by a fairly large margin, and MP4 files are readily available. I’m also considering dumping the “Moderate” workload and just sticking with Light and Heavy testing, as well as including approximate gaming battery life. There’s this mentality of “more information is always better”, but by the same token more information and testing means more time and thus less timely reviews. In general, our Medium battery life results have been pretty consistent about falling half way between our Light and Heavy tests, and with the newly modified Heavy test it’s just one extra benchmark with questionable value.
With that said, we continue to test with LCD backlighting set to 200 nits, WiFi is enabled, and earbuds are connected to the headphone jack. For the XPS 15 QHD+ display, 200 nits ended up being at exactly 50% brightness, which makes things easy on us. I do like that Dell has relatively consistent steps between backlight levels of around 35 nits per 10%. Many laptops that I’ve used in the past have been far less granular, sometimes going from 300 nits at 100% to 200 nits at 90% and then 10 nits intervals from there down to 0%.
Thanks in a large part to the 91Wh battery, the XPS 15 is able to place quite far up our battery life charts in terms of raw unplugged time. It’s not quite so awesome when we look at the normalized Min/Wh figures, but while that can be useful information at the end of the day people are going to be using the battery they get with this laptop. We measured nine hours of battery life in our light workload, nearly 6.5 hours in our moderate workload, and around 4.5 hours in our heavy workload.
Interestingly, our new Heavy test using the Video app with a lower bitrate 1080p MP4 results in battery life that’s basically the same as our previous Medium testing – so with Video, playing a fullscreen MP4 while streaming 1MBps and loading Internet pages every ten seconds isn’t really any more taxing than playing back an MP3 while surfing the web. It appears Microsoft's Video app can scale content without incurring a power penalty, whereas when I was using Media Player Classic previously higher resolution displays often did worse (e.g. look at the XPS 15 results above).
Trying to game off the mains is a different matter, however, and even with a relatively large battery the XPS 15 only manages less than two hours while running Skyrim. (If you’re wondering, for testing gaming battery life, we use the Balanced power profile with the GPU set to “Prefer Maximum Performance”. Then we load up our Skyrim save in the town of Whiterun and let the system run until the battery is drained. The camera begins to pan around the character so it’s at least moderately demanding, though other games are certainly more so.)
Facebook
Twitter
RSS
152 Comments
View All Comments
prophet001 - Thursday, March 6, 2014 - link
This kinda makes me mad about all the crappy screens they've been putting in 15+" laptops for the last 7 years.jphughan - Friday, March 7, 2014 - link
The QHD+ display is definitely not crappy; the problem is that the display was tested with Dell's questionably named "splendid mode" enabled, which grossly oversaturates colors. I wrote about it a few pages back in a reply. But I've notified Jared (the author of the article), who confirmed that he was unaware of that setting. He immediately saw its effect though and said he'll be rerunning the LCD tests.prophet001 - Friday, March 7, 2014 - link
I wasn't talking about this screen. I was talking about the screens that laptops have been using in the recent past. Like 15.6" LCDs with 1366x768 resolution.CommanderK - Thursday, March 6, 2014 - link
I bought this machine in Germany, and I sent it back. Bought maxed out configuration for 2000 Euro (now 2100), but alread for this price I had the feeling it was not worth the money. Reasons were almost the same you had here:- Throttling in games
- Touchscreen stopped working occassionally
- CPU coil whining ... this was especially annoying with fans off in the bed, but also audible in normal desktop usage
- Fan was first off, but already minimal level was annoying (and this one was almost always on when using external monitor with PSU)
Dell wanted to repair, but I refused. When selling such a top level machine at such a high price, it MUST work as expected. Originally I didn't want to, but now I simply bought another retina Macbook Pro with similar specs. It is very quiet, doesn't have such an annoying fan and almost no coil whine. And of course no throttling.
What is especially interesting is that this machine must sell like sliced bread. The price was raised and the waiting time increased. But with the even higher price, the decision for the macbook pro was even more easy (about 200 Euro difference). Dell service is good, but I don't want a machine that needs repair on arrival.
Sit down Dell, learn, try to be better next time.
CommanderK - Friday, March 7, 2014 - link
Small update: I received the machine with described flaws about three Months ago. I sent it back because I expected Dell couldn't repair the problems. Now seeing this review that my guess was right. Even worse for me from a publicity point of view, they are still selling the machines with THE SAME flaws as three months ago. This shouldn't happen.Flunk - Friday, March 7, 2014 - link
I had similar problems with the last revision of the XPS 15. It looks great, but the performance really doesn't match up to the looks or price tag. Really disappointing that Dell would do the exact same thing again.jphughan - Sunday, March 9, 2014 - link
The touchscreen was resolved with a firmware update, coil whine is still an issue (discussed above) that Dell is currently investigating due to widespread reports, and the increased wait times were because of a shortage on QHD+ panels. But I don't know how you encountered throttling on the XPS 15 and not the rMBP. Unless your XPS had a defective thermal assembly, the rMBP is known to throttle even more heavily than the XPS, partly because its 85W power adapter is totally undersized given that the combined TDP of just the CPU and GPU is I believe 95W -- and that's before counting the display, WiFi, BT, powered USB devices, etc. The rMBP under heavy load while plugged into the wall will actually DRAIN the battery as an auxiliary power source in order to make up for its AC adapter's inadequate power delivery. Anyway, sorry you had a bad experience with yours.praeses - Thursday, March 6, 2014 - link
Be sure when doing benchmarks that you are not charging the battery at the same time. Sometimes either the power draw will be too much or more likely the increased heat from the charging circuitry can cause it to start throttling.Kenazo - Thursday, March 6, 2014 - link
I'd be all over this if it had a number pad. Hard to justify it as an accountant otherwise. :)bloc - Thursday, March 6, 2014 - link
Buy a separate number pad. The rest of us want to sit in front of the monitor and the touch pad in the middle under the scroll bar. You spend $1500+ on a computer and why do people endure sitting 20 degrees to the left of the screen. Apple and Samsung got it right with their high end laptops - NO numbpads.