Fix/apple silicon performance

CHANGELOG.md

@@ -53,6 +53,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `SmartContract.fetchEvents` fixed when multiple event types existed https://github.com/o1-labs/snarkyjs/issues/627
 - Error when using reduce with a `Struct` as state type https://github.com/o1-labs/snarkyjs/pull/689
 - Fix use of stale cached accounts in `Mina.transaction` https://github.com/o1-labs/snarkyjs/issues/430
+- Fixed Apple silicon performance issue https://github.com/o1-labs/snarkyjs/issues/491
 
 ## [0.7.3](https://github.com/o1-labs/snarkyjs/compare/5f20f496...d880bd6e)
 

package.json

@@ -78,6 +78,7 @@
   },
   "dependencies": {
     "blakejs": "1.2.1",
+    "detect-gpu": "^5.0.5",
     "env": "^0.0.2",
     "isomorphic-fetch": "^3.0.0",
     "js-sha256": "^0.9.0",

src/chrome_bindings/getEfficientNumWorkers.js

@@ -0,0 +1,25 @@
+import { getGPUTier } from 'detect-gpu';
+
+export { getEfficientNumWorkers as default };
+
+// Return the most efficient number of workers for the platform we're running
+// on. This is required because of an issue with Apple silicon that's outlined
+// here: https://bugs.chromium.org/p/chromium/issues/detail?id=1228686
+async function getEfficientNumWorkers() {
+  let gpuTier = await getGPUTier();
+  let numCpus = navigator.hardwareConcurrency;
+  // gpuTier.gpu is undefined if page was rendered server side
+  let gpuModel = gpuTier.gpu || 'SSR';
+
+  var numWorkers =
+    {
+      'apple m1': 2,
+      'apple m1 pro': numCpus === 10 ? 3 : 2,
+      'apple m1 max': 3,
+      'apple m1 ultra': 7,
+      'apple m2': 2,
+      'SSR': ((numCpus / 6) >> 0) + 1,
+    }[gpuModel] || numCpus - 1;
+
+  return numWorkers;
+}

src/chrome_bindings/plonk_init.js

@@ -1,6 +1,7 @@
 import plonkWasm from './plonk_wasm.js';
 import workerRun from './worker_run.js';
 import workerInit from './worker_init.js';
+import getEfficientNumWorkers from './getEfficientNumWorkers';
 import { srcFromFunctionModule, inlineWorker } from './workerHelpers.js';
 import snarkyJsChromeSrc from 'string:./snarky_js_chrome.bc.js';
 let plonk_wasm = plonkWasm();
@@ -10,9 +11,10 @@ let { override_bindings } = workerRun();
 export async function initSnarkyJS() {
   let { memory } = await init();
   let module = init.__wbindgen_wasm_module;
+  let numWorkers = await getEfficientNumWorkers();
 
   let worker = inlineWorker(srcFromFunctionModule(workerInit));
-  worker.postMessage({ type: 'init', memory, module });
+  worker.postMessage({ type: 'init', memory, module, numWorkers });
 
   let workersReady = new Promise((resolve) => (worker.onmessage = resolve));
   await workersReady;