The situation is really pretty simple. As it ships today, the Surface Book 2 15-inch comes with a 95-watt power supply (it’s actually 102 watts, but seven watts is set aside for the USB power port). The notebook’s components, however, can consume more power than that when they’re running at full speed. The Intel Core i7-8550U CPU, for example, can use 25 watts (or even more, at times) all by itself, and the GeForce GTX 1060 GPU can draw up to 80 watts. Simple math puts those two components alone at 105 watts or more, and that’s not accounting for the display, RAM, solid-state drive (SSD), and other electronics.
What this means in practice is that if a user is really pushing the Surface Book 2’s CPU and GPU, then the power draw can exceed the power supply’s capacity. In those instances, the machine taps and drains the battery to make up the difference and eventually throttles performance, potentially leaving users with depleted batteries for mobile productivity or creating poor gaming experiences. And it’s during the most intense gaming — and as it turns out, creative productivity — sessions with today’s most demanding games and applications when this scenario is likely to occur.
We asked about the situation while we were completing our review, and a Microsoft spokesperson sent us this reply:
“Surface Book 2 was designed to deliver unmatched power and performance for anyone who needs a powerful machine to work and create, making it a great option for STEM professionals (designers, developers, engineers). The Surface Book 2 Power Mode Slider is provided as a means to give the user control over the range of performance and battery life. In some intense, prolonged gaming scenarios with Power Mode Slider set to ‘best performance,’ the battery may discharge while connected to the power supply provided in-box with Surface Book 2. However, through power management design, the battery will never drain entirely, ensuring that users are able to keep working, creating, or gaming.”
In layman’s terms, Microsoft is saying that if you crank the machine up to its highest performance setting and play Destiny 2, for example, at 1080p and at a high graphics setting, then you’re going to start depleting the battery. Do it long enough, and the machine is going to throttle the CPU and GPU to stop the battery drain. In no case will the battery deplete completely, though.
The question then becomes: Just how big of a deal is this? At first, we were going to say it’s not that big of a deal at all. That is, it’s not a big deal if you accept the premise that the Surface Book 2 is many great things — the most powerful 2-in-1 on the market, the most flexible and feature-laden notebook you can buy, and a powerful machine for creative professionals. But at the same time, it’s simply not a hardcore, dedicated gaming machine.
However, we ran some informal tests to see if Microsoft’s claim about power drain strictly during gaming holds true. Basically, we fired up Adobe’s Premiere Pro CC 2018 video editing app, imported a large AVI file, and added some effects. Then, we exported it to an MPEG4 file. In other words, we performed the kind of task that thousands of creative types are likely to perform on a daily basis. We did this with the performance slider to the right on “Best Performance” and the Surface Book 2 plugged in with fully charged batteries.
The result? Almost immediately, the battery indicator changed status from “Fully Charged” to “Plugged In, Discharging” and one of the batteries changed from “100% and fully charged” to “100% and in use.”
After about 30 minutes, the battery had drained to 96 percent remaining (95 percent on the base battery and 100 percent on the tablet battery). In fact, this particular Surface Book 2’s battery indicator had a tendency to lag, showing 100 percent until suddenly flipping to 95 percent remaining on one of the batteries. And so the battery had actually been dropping at a linear rate.
We ran some tests with the power slider in the middle at “Better Performance” and there was some discharge as well. The only way to completely avoid discharging the battery was to move the slider all the way to the left, to the “Recommended” setting. That reduced performance and the export process took longer, but it saved the battery from discharging.
The bottom line is that the Surface Book 2 will drain its battery during relatively mundane productivity tasks as well. It simply doesn’t take playing high-end gaming titles for hours at a time. While our testing wasn’t scientific, and we didn’t look for the throttling that Microsoft indicates will occur at some point to maintain battery life, we were disappointed nonetheless.
We, therefore, have to change our impressions of the Surface Book 2 a bit. Until or unless Microsoft releases a higher capacity power supply for the machine, it’s going to be of somewhat limited use not only to anyone who wants to play modern gaming titles, but also to anyone who needs a machine for high-end creativity tasks that push the CPU and GPU to their limits. While the Surface Book 2 performs well, and you might be willing to simply wait for the battery to recharge, there’s another problem: Batteries have a limited lifespan, and every discharge and charge cycle cuts it short.
There is still a chance that the Surface Book 2 will work well for AutoCAD, Sketchup, and other demanding creative applications that don’t maintain high CPU and GPU usage for long periods of time. We didn’t test every application and so we can’t say for sure if those applications will cause the battery to discharge. But if you’re considering the Surface Book 2 for this kind of work or for hardcore gaming, then you will want to make sure to test it thoroughly before your return policy ends.
Updated to reflect our additional testing that demonstrates creative applications can also cause battery discharge.
