I recently purchased a Razer Stealth 2019 - i7 4k, MX150, 16gb 512gb. I purchased this because all the reviews I read said this is the most powerful ultrabook on the market. As a photographer I need a powerful and light editing and travel laptop. For photo editing, CPU speeds (not necessarily core count) is the most important factor and the 4k display is also helpful for crisp images. My previous laptop was an HP envy 13t with similar specs - 8550u, 13.3 4k touch screen, 16gb ram, MX150, 512gb. However it was hardware TDP locked by HP where it will boost to 25w for a few seconds and drop to 15w and no amount of tweaking can unlock the TDP. I was able to a -94mv undervolt it a bit for better performance, and during Cinebench R15 it would boost to 3.1ghz before settling to 2.6ghz. Editing on that laptop was painfully slow with large 42MP raw files. I was super excited to receive the Stealth and it's a beautiful laptop. I did got a -115mv undervolt and the laptop was able to hit 4.1ghz at 40w and then 3.3ghz at 25w on Cinebench R15 plugged in getting scores between 680-735. I even tried some light games like Xcom and while not great, it was much smoother. This was amazing and much faster than my old HP. However after owning this for about a week I noticed the performance is significantly worse on battery than plugged in. I ran a whole number of tests and realized that while this has been advertised as a laptop that can do 25w CPU, the laptop resorts to 15w on battery. Even worse, there are times when the laptop will run at 10w or less. Running Cinebench R15 on battery the laptop starts out at 10w @2.1ghz and after a while then boosts to 15w @ 2.8ghz. This is the exact opposite of how turbo boost is supposed to work - turbo boost is supposed to boost speeds at the start then level off. Even worse there are times where the laptop runs at 10w @ 2.1ghz the whole time or start at 10w then jumps to 15w then back again. I would run one test, walk away and 10 min later re-run the test and get a completely different result. All of this was in best performance setting, creators mode which is supposed to boost CPU speeds. Plugged in 40w 4.1ghz then 25w 3.3ghz. Cinebench Score 712 Battery 10w 2.1ghz then 15w 2.8ghz. Cinebench score 420 Even worse, gaming performance on battery is horrendous and unplayable. While the GPU remains consistent around 1700mhz, the CPU runs at 400 mhz on battery during a game and would have tiny spikes in 1.8ghz. I've tested this repeatedly with Deus Ex and Xcom 2, both games had FPS in the teens because the CPU would not keep up. Graphics plugged in, 40 FPFS Graphics on battery, 21FPS I tried everything from changing the power settings to changing Synapse settings. I even created a new power plan for max performance and nothing changed. After much digging I found a helpful reddit post that told me to turn of BD PROCHOT in Throttlestop. (https://www.reddit.com/r/razer/comments/bvw8xq/rbs_2019_cpu_throttling_fix/) Apparently the Stealth has a hard temp limit at 60C for the CPU on battery but this same limit does not exist plugged in. With BD PROCHOT disabled I was able to play games at reasonable CPU loads. This seems like an unreasonable requirement for people to disable one thermal setting just to get the laptop to work. Even my old HP could play games at better frame rates than the Stealth. At the moment I am thinking of returning this laptop. I've had a lot of the issues people have complained about in this forum and elsewhere - loose USB C ports, battery that drains while doing heavy loads plugged in, buzzing speakers, etc. However the lack of full power on battery is a near deal breaker for me. 2.8ghz is only 200 mhz faster than my old HP and this is with a HEAFTY -115mv undervolt. I'm overall extremely disappointed by laptop because it had great potential. However the 25w TDP only plugged in which the purpose of a mobile computer to begin with. At 15w the performance is average with other laptops of the same caliber. However performance is extremely inconsistent and TDP drops to 10w or less and I can't seem to figure out why. I hope Razer would solve this issue, but it'st been half a year since this laptop has been released and this seems like a pretty huge deal (400mhz) that RAZER hasn't addressed yet. Razer is supposed to be a company for gamers, I don't know what games run at 400mhz (Sim City 2000?). And let's not forget the price, this is an expensive premium laptop. I daresay Apple does a better job than this.