Context
I’m deploying large language models on iPhone using llama.cpp. A new iPhone Air (12 GB RAM) reports a Metal MTLDevice.recommendedMaxWorkingSetSize of 8,192 MB, and my attempt to load Llama-2-13B Q4_K (~7.32 GB weights) fails during model initialization.
Environment
Device: iPhone Air (12 GB RAM)
iOS: 26
Xcode: 26.0.1
Build: Metal backend enabled llama.cpp
App runs on device (not Simulator)
What I’m seeing
MTLCreateSystemDefaultDevice().recommendedMaxWorkingSetSize == 8192 MiB
Loading Llama-2-13B Q4_K (7.32 GB) fails to complete. Logs indicate memory pressure / allocation issues consistent with the 8 GB working-set guidance.
Smaller models (e.g., 7B/8B with similar quantization) load and run (8B Q4_K provide around 9 tokens/second decoding speed).
Questions
Is 8,192 MB an expected recommendedMaxWorkingSetSize on a 12 GB iPhone?
What values should I expect on other 2025 devices including iPhone 17 (8 GB RAM) and iPhone 17 Pro (12 GB RAM)
Is it strictly enforced by Metal allocations (heaps/buffers), or advisory for best performance/eviction behavior?
Can a process practically exceed this for long-lived buffers without immediate Jetsam risk?
Any guidance for LLM scenarios near the limit?
Delve into the world of graphics and game development. Discuss creating stunning visuals, optimizing game mechanics, and share resources for game developers.
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In the Creating A 3D Application With Hydra Rendering tutorial on the Apple Developer website, on the last step where I execute this command:
cmake -S ~/Users/macuser/CreatingA3DApplicationWithHydraRendering/ -B ~/Users/macuser/CreatingA3DApplicationWithHydraRendering/
I keep getting an error:
CMake Error at CMakeLists.txt:5 (include):
include could not find requested file:
/Users/macuser/USDInstall/bin/pxrConfig.cmake
I've tried to follow the instructions as mentioned in the README.md file included in the project files at least 5 times as well as moving the pxrConfig.cmake file around and copying it in different folders, then executed the command and was still unsuccessful into generating the proper file expected to compile and render the HydraPlayer renderer. How do I get cmake to generate the Xcode file to create the HydraPlayer renderer?
Like many folks here, I've recently attempted to build Apple's Game Porting Toolkit on my machine and ran into compiler errors, but instead of going the usual route of downloading the prebuilt package (kindly provided by GCenX), I decided to see if I could force it to build (since it was obviously buildable at some point). Down below is the list of things I had to do to make it work.
Disclaimer: There are several dirty hacks I had to attempt to force the system to do what I needed. Use at your own risk.
Don't forget to run all brew commands from a Rosetta prompt:
arch -x86_64 zsh
Install openssl
This one is easy. Just run
brew tap rbenv/tap
brew install rbenv/tap/openssl@1.1
Install Command Line Tools 15.1
This specific version is required since newer versions come with the linker that is not compatible with the custom compiler (game-porting-toolkit-compiler) that GPTK is using. However, by default 15.1 tools won't install on Sequoia since the installer complains that macOS version is too new. Obviously, Apple has their reasons to not allow this, but all we need is a compiler which should be mostly indifferent to the OS version.
To trick the installer, we need to change OS requirement of the installer package. You can do it in four easy steps:
Copy Command Line Tools.pkg from the mounted Command_Line_Tools_for_Xcode_15.1.dmg to some other directory.
Expand the installer package:
pkgutil --expand "Command Line Tools.pkg" CLT
You might be prompted to install Command Line Tools when you call pkgutil, just install any version.
Go to the newly created CLT folder and edit the Distribution file (it may appear as executable but it's just an xml). You would want to change allowed-os-versions to something greater than 15. Removing this section altogether might also work.
When done, re-wrap the package:
pkgutil --flatten CLT "Command Line Tools 2.pkg"
Congratulations, now you should be able to install 15.1 tools on your OS! If you had to install newer Command Line Tools for pkgutil, delete them before installing 15.1:
sudo rm -rf /Library/Developer/CommandLineTools
Next step is to make Homebrew accept the outdated 15.1 tools, as by default it'll complain that they're outdated or corrupted. To shut it up, open
/usr/local/Homebrew/Library/Homebrew/extend/os/Mac/diagnostic.rb
and remove references to check_if_supported_sdk_available from a couple of fatal build check collections.
Note - by default, Homebrew will auto-update on any invocation, which will overwrite any changes you've made to its internals. To disable this behavior, before running any brew commands in the terminal, run
export HOMEBREW_NO_AUTO_UPDATE=1
After these manipulations, Homebrew might still complain about outdated Command Line Tools, but it won't be a fatal error anymore.
Finally, we need to downgrade MinGW to 11.0.1, since the latest version spits out compiler errors when compiling Wine. Unfortunately, Homebrew does a bad job tracking versions of MinGW, so there is no automatic way to do it. Instead, you have to manually download and install old MinGW 11.0.1 formula from the Homebrew git repository. I used the commit from Sep 16, 2023:
https://github.com/Homebrew/homebrew-core/blob/b95f4f9491394af667943bd92b081046ba3406f2/Formula/m/mingw-w64.rb
Download the file above, save it in your current working directory, and then run
brew install ./mingw-w64.rb
If you had a newer version of MinGW already installed from the previous build attempts, you can unlink it before installing the one above:
brew unlink mingw-w64
With Command Line Tools 15.1 and MinGW 11.0.1 you should now be able to build GPTK without errors:
brew -v install apple/apple/game-porting-toolkit
In the end, steps above worked for me, although more things could break in the future. I'm leaving the instructions here just to show that it's still possible to build GPTK manually instead of relying on third parties, but with all the hoops I had to jump through I can't really recommend it.
Hello!
I'm a developer working on a plugin for the Elgato Stream Deck, called GPU Metrics. The plugin currently only works on Windows but I'd like to bring it to macOS. However, based on forum posts I've read (and StackOverflow) there isn't a very clear path to query GPU metrics like usage, temperature, used GPU memory, and power consumption. There are some tools out there that do similar things, but I wanted to see what would be the recommendation from Apple's engineering team to get this data via a public API.
Requirements:
Access GPU utilization, temperature, memory usage, power usage
C/C++ based API for querying the metrics so I can expose the data to JavaScript via Node Addon
No need to compatibile with Intel-based Macs, as Apple silicon will be fine for now
Plugin GitHub
Thank you!
Noah
Deterministic RNG behaviour across Mac M1 CPU and Metal GPU – BigCrush pass & structural diagnostics
Hello,
I am currently working on a research project under ENINCA Consulting, focused on advanced diagnostic tools for pseudorandom number generators (structural metrics, multi-seed stability, cross-architecture reproducibility, and complementary indicators to TestU01).
To validate this diagnostic framework, I prototyped a small non-linear 64-bit PRNG (not as a goal in itself, but simply as a vehicle to test the methodology).
During these evaluations, I observed something interesting on Apple Silicon (Mac M1): • bit-exact reproducibility between M1 ARM CPU and M1 Metal GPU, • full BigCrush pass on both CPU and Metal backends, • excellent p-values, • stable behaviour across multiple seeds and runs.
This was not the intended objective, the goal was mainly to validate the diagnostic concepts, but these results raised some questions about deterministic compute behaviour in Metal.
My question: Is there any official guidance on achieving (or expecting) deterministic RNG or compute behaviour across CPU ↔ Metal GPU on Apple Silicon? More specifically:
• Are deterministic compute kernels expected or guaranteed on Metal for scientific workloads?
• Are there recommended patterns or best practices to ensure reproducibility across GPU generations (M1 → M2 → M3 → M4)? • Are there known Metal features that can introduce non-determinism?
I am not sharing the internal recurrence (this work is proprietary), but I can discuss the high-level diagnostic observations if helpful.
Thank you for any insight, very interested in how the Metal engineering team views deterministic compute patterns on Apple Silicon.
Pascal ENINCA Consulting
Topic:
Graphics & Games
SubTopic:
Metal
GKAccessPoint triggerAccessPointWithState handler not invoked on iOS 26.0 and iOS 15.8.4
Incorrect/Unexpected Behaviour:
When calling [GKAccessPoint.shared triggerAccessPointWithState:GKGameCenterViewControllerStateAchievements handler:^{}] on a real device running iOS 26 beta (iOS 26), the overlay appears as expected, but the handler block is never called. This behavior also not working correctly on previous iOS versions(tested on iOS 15.8.4)
Steps to Reproduce:
Authenticate GKLocalPlayer
Call triggerAccessPointWithState:handler: with a block that logs or performs logic
Observe that overlay appears, but block is not executed
Behavior:
UI appears correctly
Handler is not invoked at all
Expected Result:
The handler should fire immediately after the dashboard is shown.
Actual Result:
The handler is never called.
Usecase:
As GKGameCenterViewController is deprecated we are moving to GKAccesspoint but due to above functionality issue we are unable to.
Environment:
Device: iPhone 16, iPhone 7
iOS: 26.0 and iOS 15.8.4
Xcode: 26.0 beta and Xcode 16.4
我们想在游戏类 App 内接入 Game Center。用户可以在游戏内创建多个角色,若用户在游戏内创建了2个角色:角色1、角色2,请问:
当用户将角色1与 Game Center 绑定后,数据将上报至 Game Center。此时玩家想要将角色1与 Game Center 解除绑定,解绑后,再将角色2与 Game Center 绑定。那么这时角色1的数据是留存在 Game Center 中,还是将被移除?
When running on my iPhone SE3 under IOS 18.4.1, achievement banners show as expected. The same code running on my iPad Air2 under IOS 15.8.4, achievement banners do not show, but they are accepted (as shown in the GameCenterViewController). The banners also don't show when running the simulator under iPhone 16 Pro Max under IOS 18.2 or simulator under iPhone SE3 under IOS 18.3. I haven't tried others. [Note that I clear the achievements each run during test so that I can duplicate this]
Topic:
Graphics & Games
SubTopic:
GameKit
Hi!
Using ARView in UIKit or through a UIViewRepresentable in SwiftUI, we can do:
arView.debugOptions = [.showPhysics, .showStatistics]
What is the equivalent in RealityView?
Topic:
Graphics & Games
SubTopic:
RealityKit
I have been tasked with creating content for the Apple Vision Pro. Just the 3D content and animation, not the programming end of things.
I can't seem to get any kind of mesh deformation animation to import into Reality Composer Pro. By that I mean bones/skin, or even point cache.
I work on PC, and my main software is 3DS Max, but I'm borrowing an iMac for this job, and was instructed to use RCP on it for testing before handing things off to the programmer. My files open and play fine in other USD programs, like Omniverse, or USD View, just not Reality Composer Pro.
I've seen the dinosaur demo in AVP, so I know mesh deformation is possible. If there are other essential tools that might make this possible, I have not been made aware of them.
I am experimenting with bouncing things off of Blender, in case that exports better, but not really having luck there either -though my results are different.
Thanks.
Topic:
Graphics & Games
SubTopic:
RealityKit
Hello Apple team,
I'm working on an iOS AR app using SwiftUI and RealityKit,
and I was wondering if the Cinematic API can be used with a RealityKit scene. I’d like to achieve a shallow depth of field while keeping the 3D asset in focus, and vice versa.
Thanks!
I am using Unity's GameKit to implement a turnbase game.
I want to make a UI in Unity to show all the games I can join.
I tried using
var matches = await GKTurnBasedMatch.LoadMatches();
to get all the open matches.
But it seems that I can only get the matcm related to the current apple account.
Can you help me get all the matches?
ALSO
I used
var match = await GKTurnBasedMatchmakerViewController.Request(request);
to exit the gamecenter interface and start a game (automatic matching, no one was invited)
Another device used
var match = await GKTurnBasedMatch.Find(request);
to find the game, but it did not find the game, but it start a new game (automatic matching).
Can you help me solve these problems?
What is the current [most recent] best practice to instancing Meshes in RealityKit?
I see both MeshInstanceComponent and MeshInstanceCollection.
My intent is to bind a transform to a Circle Agent (GameplayKit Agent), and feed that result to Instancing.
Hello, I’m porting my UIKit/SceneKit app to SwiftUI/RealityKit and I’m wondering how to change the camera target programmatically. I created a simple scene in Reality Composer Pro with two spheres. My goal is straightforward: when the user taps a sphere, the camera should look at it as the main target.
Following Apple’s videos, I implemented the .gesture modifier and it is printing the tapped sphere correctly, but updating my targetEntity state doesn’t change anything, so the camera won't update its target. Is there a way to access the scene content at that level? Or what else should I do?
Here’s my current code implementation:
Thanks!
I implemented an EntityAction to change the baseColor tint - and had it working on VisionOS 2.x.
import RealityKit
import UIKit
typealias Float4 = SIMD4<Float>
extension UIColor {
var float4: Float4 {
if
cgColor.numberOfComponents == 4,
let c = cgColor.components
{
Float4(Float(c[0]), Float(c[1]), Float(c[2]), Float(c[3]))
} else {
Float4()
}
}
}
struct ColourAction: EntityAction {
// MARK: - PUBLIC PROPERTIES
let startColour: Float4
let targetColour: Float4
// MARK: - PUBLIC COMPUTED PROPERTIES
var animatedValueType: (any AnimatableData.Type)? { Float4.self }
// MARK: - INITIATION
init(startColour: UIColor, targetColour: UIColor) {
self.startColour = startColour.float4
self.targetColour = targetColour.float4
}
// MARK: - PUBLIC STATIC FUNCTIONS
@MainActor static func registerEntityAction() {
ColourAction.subscribe(to: .updated) { event in
guard let animationState = event.animationState else { return }
let interpolatedColour = event.action.startColour.mixedWith(event.action.targetColour, by: Float(animationState.normalizedTime))
animationState.storeAnimatedValue(interpolatedColour)
}
}
}
extension Entity {
// MARK: - PUBLIC FUNCTIONS
func changeColourTo(_ targetColour: UIColor, duration: Double) {
guard
let modelComponent = components[ModelComponent.self],
let material = modelComponent.materials.first as? PhysicallyBasedMaterial
else {
return
}
let colourAction = ColourAction(startColour: material.baseColor.tint, targetColour: targetColour)
if let colourAnimation = try? AnimationResource.makeActionAnimation(for: colourAction, duration: duration, bindTarget: .material(0).baseColorTint) {
playAnimation(colourAnimation)
}
}
}
This doesn't work in VisionOS 26. My current fix is to directly set the material base colour - but this feels like the wrong approach:
@MainActor static func registerEntityAction() {
ColourAction.subscribe(to: .updated) { event in
guard
let animationState = event.animationState,
let entity = event.targetEntity,
let modelComponent = entity.components[ModelComponent.self],
var material = modelComponent.materials.first as? PhysicallyBasedMaterial
else { return }
let interpolatedColour = event.action.startColour.mixedWith(event.action.targetColour, by: Float(animationState.normalizedTime))
material.baseColor.tint = UIColor(interpolatedColour)
entity.components[ModelComponent.self]?.materials[0] = material
animationState.storeAnimatedValue(interpolatedColour)
}
}
So before I raise this as a bug, was I doing anything wrong in the former version and got lucky? Is there a better approach?
I'm running into an issue with collisions between two entities with a character controller component. In the collision handler for moveCharacter the collision has both hitEntity and characterEntity set to the same object. This object is the entity that was moved with moveCharacter()
The below example configures 3 objects.
stationary sphere with character controller
falling sphere with character controller
a stationary cube with a collision component
if the falling sphere hits the stationary sphere then the collision handler reports both hitEntity and characterEntity to be the falling sphere. I would expect that the hitEntity would be the stationary sphere and the character entity would be the falling sphere.
if the falling sphere hits the cube with a collision component the the hit entity is the cube and the characterEntity is the falling sphere as expected.
Is this the expected behavior? The entities act as expected visually however if I want the spheres to react differently depending on what character they collided with then I am not getting the expected results. IE: If a player controlled character collides with a NPC then exchange resource with NPC. if player collides with enemy then take damage.
import SwiftUI
import RealityKit
struct ContentView: View {
@State var root: Entity = Entity()
@State var stationary: Entity = createCharacter(named: "stationary", radius: 0.05, color: .blue)
@State var falling: Entity = createCharacter(named: "falling", radius: 0.05, color: .red)
@State var collisionCube: Entity = createCollisionCube(named: "cube", size: 0.1, color: .green)
//relative to root
@State var fallFrom: SIMD3<Float> = [0,0.5,0]
var body: some View {
RealityView { content in
content.add(root)
root.position = [0,-0.5,0.0]
root.addChild(stationary)
stationary.position = [0,0.05,0]
root.addChild(falling)
falling.position = fallFrom
root.addChild(collisionCube)
collisionCube.position = [0.2,0,0]
collisionCube.components.set(InputTargetComponent())
}
.gesture(SpatialTapGesture().targetedToAnyEntity().onEnded { tap in
let tapPosition = tap.entity.position(relativeTo: root)
falling.components.remove(FallComponent.self)
falling.teleportCharacter(to: tapPosition + fallFrom, relativeTo: root)
})
.toolbar {
ToolbarItemGroup(placement: .bottomOrnament) {
HStack {
Button("Drop") {
falling.components.set(FallComponent(speed: 0.4))
}
Button("Reset") {
falling.components.remove(FallComponent.self)
falling.teleportCharacter(to: fallFrom, relativeTo: root)
}
}
}
}
}
}
@MainActor
func createCharacter(named name: String, radius: Float, color: UIColor) -> Entity {
let character = ModelEntity(mesh: .generateSphere(radius: radius), materials: [SimpleMaterial(color: color, isMetallic: false)])
character.name = name
character.components.set(CharacterControllerComponent(radius: radius, height: radius))
return character
}
@MainActor
func createCollisionCube(named name: String, size: Float, color: UIColor) -> Entity {
let cube = ModelEntity(mesh: .generateBox(size: size), materials: [SimpleMaterial(color: color, isMetallic: false)])
cube.name = name
cube.generateCollisionShapes(recursive: true)
return cube
}
struct FallComponent: Component {
let speed: Float
}
struct FallSystem: System{
static let predicate: QueryPredicate<Entity> = .has(FallComponent.self) && .has(CharacterControllerComponent.self)
static let query: EntityQuery = .init(where: predicate)
let down: SIMD3<Float> = [0,-1,0]
init(scene: RealityKit.Scene) {
}
func update(context: SceneUpdateContext) {
let deltaTime = Float(context.deltaTime)
for entity in context.entities(matching: Self.query, updatingSystemWhen: .rendering) {
let speed = entity.components[FallComponent.self]?.speed ?? 0.5
entity.moveCharacter(by: down * speed * deltaTime, deltaTime: deltaTime, relativeTo: nil) { collision in
if collision.hitEntity == collision.characterEntity {
print("hit entity has collided with itself")
}
print("\(collision.characterEntity.name) collided with \(collision.hitEntity.name) ")
}
}
}
}
#Preview(windowStyle: .volumetric) {
ContentView()
}
Hello,
I found an issue with the Games app on macOS 26 (Tahoe) when viewing achievements:
In App Store Connect, each achievement has different values set for the pre-earned description and the post-earned description.
When testing with GameKit directly (GKAchievementDescription), both values are returned correctly.
However, in the macOS Games app, the post-earned description is shown even before the achievement is earned.
This seems to be a display issue specific to the Games app on macOS.
Could you confirm if this is a known bug in the Games app, or if there is a reason why pre-earned descriptions are not being shown?
Thank you.
I am trying to load some PNG data with MTKTextureLoader newTextureWithData,but the result shows wrong at the alpha area.
Here is the code. I have an image URL, after it downloads successfully, I try to use the data or UIImagePNGRepresentation (image), they all show wrong.
UIImage *tempImg = [UIImage imageWithData:data];
CGImageRef cgRef = tempImg.CGImage;
MTKTextureLoader *loader = [[MTKTextureLoader alloc] initWithDevice:device];
id<MTLTexture> temp1 = [loader newTextureWithData:data options:@{MTKTextureLoaderOptionSRGB: @(NO), MTKTextureLoaderOptionTextureUsage: @(MTLTextureUsageShaderRead), MTKTextureLoaderOptionTextureCPUCacheMode: @(MTLCPUCacheModeWriteCombined)} error:nil];
NSData *tempData = UIImagePNGRepresentation(tempImg);
id<MTLTexture> temp2 = [loader newTextureWithData:tempData options:@{MTKTextureLoaderOptionSRGB: @(NO), MTKTextureLoaderOptionTextureUsage: @(MTLTextureUsageShaderRead), MTKTextureLoaderOptionTextureCPUCacheMode: @(MTLCPUCacheModeWriteCombined)} error:nil];
id<MTLTexture> temp3 = [loader newTextureWithCGImage:cgRef options:@{MTKTextureLoaderOptionSRGB: @(NO), MTKTextureLoaderOptionTextureUsage: @(MTLTextureUsageShaderRead), MTKTextureLoaderOptionTextureCPUCacheMode: @(MTLCPUCacheModeWriteCombined)} error:nil];
}] resume];
Hello,
MacOS 26 Betas are limiting games (noticeably, games that use java) to the native display of the MacBook Pro (120hz). Even connecting an external display this is not changing. I have submitted a bug report, but I have not had any responses to it yet. I am looking to see if anyone may have an answer or fix to this issue.
Thanks!
Topic:
Graphics & Games
SubTopic:
General
App Storeにある『浮遊時計 Premium』は1Hzごとか10Hzごと、または3段階以上のリフレッシュレート計測はできますか?
Topic:
Graphics & Games
SubTopic:
General