Merge Switch 2 work from local Eden (nx2 at b0dd3fe)

1 files changed, 12 insertions, 2 deletions

diff --git a/src/video_core/textures/workers.cpp b/src/video_core/textures/workers.cpp
index a1953c4bf4..e3a0f26cf2 100644
--- a/src/video_core/textures/workers.cpp
+++ b/src/video_core/textures/workers.cpp
@@ -4,13 +4,23 @@
 // SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+#include <cstdlib>
+
 #include "video_core/textures/workers.h"
 
 namespace Tegra::Texture {
 
 Common::ThreadWorker& GetThreadWorkers() {
-    static Common::ThreadWorker workers{(std::max)(std::thread::hardware_concurrency(), 2U) / 2,
-                                        "ImageTranscode"};
+    // A quarter of the hardware threads (at least 2). Half took ~3.5 cores from the emulated
+    // CPU cores and the GPU thread on an 8-core laptop when textures were thrashing; with an
+    // eighth (2) both threads stayed saturated and streamed textures arrived seconds late (shown
+    // as placeholders), while 4 cost no frame rate. EDEN_NX2_TRANSCODE_THREADS=<n> overrides.
+    static Common::ThreadWorker workers{[] {
+        if (const char* text = std::getenv("EDEN_NX2_TRANSCODE_THREADS")) {
+            return (std::max)(static_cast<u32>(std::strtoul(text, nullptr, 10)), 1U);
+        }
+        return (std::max)(std::thread::hardware_concurrency() / 4, 2U);
+    }(), "ImageTranscode"};
     return workers;
 }