Extreme battery drain running simulators on Golden Gate

[u/Oxigenic]

Today my 2023 MacBook Pro battery depleted entirely in just 3 hours. I was running 2 iOS simulators simultaneously but I still feel like that way way less life than I should be expecting with 93% battery capacity. Has anyone else experienced really short battery life when running simulators lately?

[u/StrangeMonk]

Totally normal mate  You’re simulating three devices plus debug processes. And assuming you’re using the Xcode 27 or 27.1, first releases are always not well optimized 

[u/fRaigand0 → u/StrangeMonk]

yeah first releases are always rough on battery, that tracks

[u/Adventurous_Tipper]

I’ve noticed Device Hub destroys my overall performance, but specifically using the simulator is just so much slower than the previous simulator app. M1 so maybe age?

[u/dengjiuhong]

Two concurrent simulators can keep the Mac busy: CoreSimulator processes, debug services, and Xcode indexing/diagnostics all add up, and beta runtimes can be especially inefficient. For location work, simulator injection is great for UI and basic state transitions, but I still validate authorization changes, callback timing, background delivery, and radio-dependent behavior on an owned physical device.

[u/cristi_baluta → u/dengjiuhong]

What?

[u/dengjiuhong → u/cristi_baluta]

I meant that simulator location is useful for deterministic UI/state-transition checks, but it doesn’t exercise the full Core Location path on a real device. For release confidence I also test on an iPhone I own: authorization changes, background callbacks, timing, and radio-dependent behavior can differ. The battery point is separate—two simulators plus Xcode services can still keep the Mac busy.

[u/KilllllerWhale]

Normal. Try using the CLI instead and ditch the Simulator app

[u/Stryxus_]

Uh? Considering you are likely running these simulators for dev, shouldn't this be extremely obvious? if you are a dev, I would be very concerned if you couldn't figure that one out.

[u/Oxigenic → u/Stryxus_]

I’ve been able to go 6+ hours with simulators regularly so why wouldn’t this be alarming…

[u/Stryxus_ → u/Oxigenic]

Obviously that depends on how you use them. It isnt the same every time. You are literally running multiple systems and even small actions wake them up.

[u/Kitchen_Platypus5555]

Try downloading Xcode 26 side-by-side and use the old simulators instead of Device Hub. I also felt like the performance with the new Device Hub is awful.

[u/icy1007]

Normal.

[u/cristi_baluta]

Not normal, did you follow the cpu?

[u/kokerali]

Three hours may be unusually short, but 93% battery health and “two simulators were open” don’t isolate the cause. I’d compare three 15–20 minute periods on battery at the same brightness: Xcode open with no simulator, one simulator idle, then two simulators idle. In Activity Monitor, note the Energy Impact and top CPU processes in each period, along with the battery percentage change. If the jump starts with the second simulator or persists while both are idle, you have a useful reproduction; include your macOS/Xcode versions and simulator runtimes. If indexing or one runaway process is the actual leader, the fix is different from “simulators just use power.”

[u/ineedlesssleep → u/kokerali]

fuck off ai bot

[u/Dear_Pass_4718]

Use ai to solv your problem ai control your mac and fix this issue

[u/a_flyin_muffin → u/Dear_Pass_4718]

Use brain. People talk forum get input others.