Microsoft’s 15-inch Surface Book 2 laptop suffers from battery drain during heavy gaming or GPU usage, a problem The Verge first identified during our review of the device last week. While plugged into the supplied charger, the battery on the base of the device will drain during certain games if the power settings are set to max performance to fully utilize the power of the hardware.

“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),” explains a Microsoft spokesperson in a statement to The Verge. “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.”

The amount of drain varies between games, screen resolution, and maximum load on the GPU. We’re still carrying out additional tests on a new Surface Book 2 unit after a defective power supply caused additional issues on our review unit. The max performance setting is required to play games, as during my tests I’ve found that performance rapidly drops during the other battery-efficient settings.

There’s not enough power from the supply

It appears that the Surface Book 2 has been designed to supply 95 watts of power from the charger to the device, which isn’t enough to run the processor, graphics card, and all other hardware components at max. The processor alone draws 25 watts in high-power mode, and will even burst to 35 watts. Microsoft’s Nvidia GTX 1060 variant draws between 70 and 80 watts, bringing the total to 105 watts at peak. Microsoft works around this by aggressively throttling the Nvidia chip during games at “better performance” and “best battery” settings.

I’ve found the throttling makes the device unusable for gaming after less than 10 minutes in those battery efficient modes, dropping the experience from 60fps to 30fps in some titles. Other games will run fine in these modes, but Destiny 2 is particularly grueling. The max performance setting will drain power even when plugged into the wall, and I’ve found it’s at least 10 percent an hour or more depending on the game and load.

We’re still carrying out additional tests to update our Surface Book 2 review, but it’s clear that the device is not designed to be a gaming laptop. Microsoft has made some trade-offs in its design to avoid a heavy power brick and reaching the maximum 120 watts that the Surface Connector currently supports. Those trade-offs mean you’re not going to be able to play games at high resolution with high settings without some form of battery drain or throttling of the graphics card performance even when you’re plugged into the wall.