Choosing between the Lumia 950 and 950 XL: it’s not so easy to do

Mark Coppock

Lumia 950

I have a preorder in on a Lumia 950 XL, which should arrive sometime this month by most estimates. It’s a soft preorder, basically just dibs on one of the first units to arrive at my local Microsoft Store. I didn’t give any credit card information, no money change hands, and so I’m not locked in as I would be with a “real” preorder.

That’s a good thing, because I’m not 100% sure that I want the 950 XL–part of me is still considering its smaller sibling, the 950. And, it’s not just the difference in size that gives me pause. There’s also the price: the 950 Xl is expected to retail for $649, a cool $100 more than the 950. That would pay for a Display Dock, which is “coming soon” at $99 and supports Windows 10 Mobile Continuum and adds a few additional ports.

In many important ways, of course, the two smartphones are essentially the same. They share some of the more important specifications:

  • 3GB RAM
  • 32GB storage with microSD support up to 200GB
  • 2560X1440 WQHD resolution
  • Corning Gorilla Glass 4
  • 20MP rear camera with ZEISS optics, PureView, backside-illuminated sensor, optical image stablization, 4K video
  • 5MP front camera will Full HD video
  • Windows Hello support via iris scanner
  • Build-in Qi wireless charging and fast charging
  • USB-C
  • Full set of sensors (ambient light, accelerometer, proximity, barometer, gyroscope, magnetometer, SensorCore)

But as much as the two Lumias have in common, some important differences remain:

950 950 XL
Body size 8.2 x 145 x 73.2 mm 8.1 x 151.9 x 78.4 mm
Screen Size 5.2” 5.7”
PPI 564 518
Processor Qualcomm Snapdragon 808 Qualcomm Snapdragon 810
Clock Speed 1.8 GHz 2.0GHz
Number of Cores 6 8
Battery size 3000 mAh 3340 mAh

These combine as the attributes that are causing me the most angst as I decide where to put my money.

First, there’s the screen
I love high-quality screens, particularly those with bright (but natural) colors, good outdoor viewability, deep blacks, and good contrast. Lumias have always had great screens, and the new flagships should be no different by virtue of using AMOLED and ClearBlack technologies and given Microsoft’s recent commitment to using excellent screens in general.

I also love high-resolution screens–the higher the better, in fact. I read a lot, including tons of news and scads of ebooks. I read on all of my devices, every chance I get–if I have a few free minutes, I don’t play a quick game or check Facebook. I read something. I’d go so far as to say that reading is one of the most important things I do on smaller devices, both tablets and smartphones.

Since I stare at so much text, I like my screens as sharp as possible. Simply put, I hate to look at pixels. In fact, I admit to buying an iPad 3 back in the day with its then-industry-leading Retina screen after randomly glancing at one at a Frys in the San Fernando Valley. I had no desire at the time to buy an iOS device, but I was simply blown away by the quality of the text–it was vastly superior to anything else available at the time, and reading ebooks on the iPad 3 was a vastly superior experience.

My fixation with resolution makes the choice between the 950 (2560X1440, 564 PPI) and 950 XL (2560X1440, 518 PPI) a little more difficult, at least in theory. Believe me, my rational mind tells me that in all likelihood I won’t be able to tell the difference between the two without a microscope. Individuals pixels are just about impossible to discern at reasonable distances at 518 PPI, and 564 PPI won’t be noticeably sharper.

Even so, I’ll know that the difference exists. And like I said, I love high-res screens, the higher the better. And so the extra PPI is attractive to me just to be sure that I have the highest resolution available.

Lumia 950s

At the same time, the 950 XL has a 5.7″ screen vs. the 950’s 5.2″ screen. That’s attractive as well given that my eyes are getting older by the minute and I need reading glasses to see what’s on these screens anyways. A larger screen would make for bigger on-screen elements, and so the lower resolution (although still ridiculously high) is balanced out.

Of course, a smartphone with a 5.7″ screen is also noticeably larger than a smartphone with a 5.2″ screen. I carry my smartphones in my right-front pants pocket, and so far I’ve never owned a device with larger than a 5″ screen (my Lumia 830 is my largest yet). The 950 XL doesn’t have huge bezels, and so it’s much smaller than, say, the Lumia 1520 with its 6″ screen, which was simply too large for me.

The size decision, though, is the easiest of all–I’ll just need to try them side-by-side to see if the 950 XL is less comfortable to carry than the 950. Looking at online size comparisons in the meantime, the 950 XL doesn’t appear to be such a huge device. In fact, my colleague Kip shared some of the same concerns, but decided on the 950 XL when he managed to get his hands on one and discovered the size to be manageable.

Here’s where the Lumia 950 and Lumia 950 XL stack up against each other and some of the competition (via’s comparison tool). Although I’m looking forward to trying them both out in person, the 950 XL might be a decent compromise between screen size, resolution, and overall device size.

The Lumia 950 XL's size might be just right.
The Lumia 950 XL’s size might be just right.

Winner: Lumia 950 XL (unless I try it first-hand and just find it to be too large)

The 950 XL has a Snapdragon 810 SoC on board, which on paper should make for a faster device compared to the Snapdragon 808 SoC used by the 950. The 810 has eight cores vs. 808’s six cores, a higher clock speed, and a faster GPU (the Adreno 430 vs. the Adreno 418).

However, the 810 has developed something of a reputation for suffering from some thermal throttling issues–while the 810 starts out quickly against its competition, some tests have shown a tendency for the chip to slow down as things heat up. Running the same processor-intensive tasks over and over–say, gaming or multitasking–seems to cause the 810 to reduce its clock speed to cool down in some devices.

In the following graph from Ars Technica, the 810 (in the LG G Flex 2) is clearly faster than the 808 (LG G4) while cool, but performance drops significantly once it’s warmed up.

The Snapdragon 810 might very well slow down as it heats up.
The Snapdragon 810 might very well slow down as it heats up.

The following graph (again from Ars Technica) demonstrates the throttling phenomenon.

The Snapdragon 810 throttling as it heats up, while the 808 keeps chugging along.
The Snapdragon 810 throttling as it heats up, while the 808 keeps chugging along.

Further complicating matters, the latest version of the 810, V2.1, which presumably is being used in the 950 XL, is supposed to have improved things, at least somewhat. Evidence suggests, however, that the issue may still not be fully resolved.

All I can say is: whew! At this point in my research, frankly, I’m left with no idea just how big the issue ever was, if it’s been fully resolved, or if there are any thermal issues remaining. I suspect that problem did exist and still does, to a lesser extent, and that it’s something at least worth considering when choosing between a Lumia 950 and a Lumia 950 XL. That’s going to be my approach, anyways.

In any event, Microsoft added liquid cooling to the 950 XL that should (theoretically, at least) help reduce or eliminate any thermal throttling that might otherwise occur (if any). Finally, Microsoft should have fully tested the thermal and overall performance of the 950 XL and created a design that will suffice in ensuring the best possible experience. Certainly, we hope that they’ve done so.

The Lumia 950's liquid cooling pipe.
The Lumia 950’s liquid cooling pipe.

As I mentioned earlier, I plan to buy the Display Dock, specifically to test the Windows 10 Continuum functionality. I’d hoped that the 950 XL’s faster CPU and GPU would come in handy when driving an external monitor and pushing the system while getting real work done. Now, though, I’m left with a couple of questions.

Do I take the chance that Microsoft has fully resolved any existing thermal issues in the Snapdragon 810? Or, do I fall back to the 950 and its Snapdragon 808 processor that has two fewer cores and a slower GPU, but that seems to possess superior thermal performance? Those are tough questions, and really only time will tell if Microsoft has managed to tame the 810’s troubles.

More than anything, this is the consideration that’s giving me the most pause. The Snapdragon 810’s extra cores and faster GPU won’t be of much use if the processor is constantly throttling due to overheating. Then again, will Continuum really push the processors that hard? Driving a second monitor is something that smartphone’s don’t tend to do, but then again Office Mobile and most Windows 10 productivity apps aren’t exactly CPU- or GPU-intensive. I don’t use my smartphones as gaming devices, and so that’s not an important consideration to me.

Will running full-screen apps on an external monitor push the Snapdragon 810 to throttle?
Will running full-screen apps on an external monitor push the Snapdragon 810 to throttle?

Winner: In the end, this one’s a toss-up for me. Buy the 950 XL and risk getting stuck with a device that runs hotter and slower, or buy the 950 and potentially end up with a device that runs slower, period. Microsoft has a mixed record of producing hardware with good thermal management–my own Surface Pro 3 has been a mixed bag in this regard, performing hotter and cooler depending on the firmware revision–and so their past performance is no guarantee of future results.

Battery Life
I’m listing battery size as a criterion in choosing between the two sibling smartphones simply because battery life is important to me. Having a replaceable battery is a nice feature that’s shared by both devices, but I’d rather not carry an extra battery unless I really have to do so. Once again, however, it’s not at all clear which of the smartphones is going to be the better choice.

The Lumia 950 XL has a larger, 3,340mAh battery compared to the 950’s 3,000mAh battery. The 950 XL also has a larger screen and a more powerful SoC. Will the roughly 11% increase in battery life overcome the increased power draw? Again, that remains to be seen, and will depend on a whole host of variables that we don’t really know at this point.

Winner: Likely another draw, but also likely to be close enough that it doesn’t really matter.

So, which will I choose?
I started out this analysis considering three primary factors in choosing between the Lumia 950 XL and the Lumia 950: screen/device size, processor concerns, and battery life. As I wrap things up, I’m not much farther along than I was when I started:

  • In terms of screen/device size, arguments can be made for either smartphone–the 950 XL has a larger screen with lower (possibly irrelevant) resolution and a larger physical size, whereas the 950 has a smaller screen with higher (and again, possibly irrelevant) resolution and a more comfortable physical size.
  • The 950 XL has a faster processor on paper with the potential for thermal throttling that could limit performance, balanced by a liquid cooling system that might obviate those concerns. The 950 has a processor that’s slower on paper but has demonstrated overall faster performance–at least in some devices.
  • The 950 XL has a larger battery but more power-hungry components, likely resulting in a draw.

When all is said and done, I’m still leaning towards the 950 XL. It doesn’t appear to be too large, I’ll put my trust in Microsoft that they’ve designed around any potential issues with what should be a very well-performing SoC, and battery life should be no worse than with the 950. I tend to buy as much machine as I can when I make a technology investment, because it’s better to have something and not need it than need something and not have it. And $100 isn’t such a significant difference that the price alone makes a significant difference.

Now, if Microsoft would just go ahead and release the things, already.