diff --git a/src/gpu/vk/GrVkAMDMemoryAllocator.cpp b/src/gpu/vk/GrVkAMDMemoryAllocator.cpp
index 4ee457f..db93e4f 100644
--- a/src/gpu/vk/GrVkAMDMemoryAllocator.cpp
+++ b/src/gpu/vk/GrVkAMDMemoryAllocator.cpp
@@ -43,9 +43,10 @@
     info.flags = 0;
     info.physicalDevice = physicalDevice;
     info.device = device;
-    // Manually testing runs of dm using 64 here instead of the default 256 shows less memory usage
-    // on average. Also dm seems to run faster using 64 so it doesn't seem to be trading off speed
-    // for memory.
+    // 4MB was picked for the size here by looking at memory usage of Android apps and runs of DM.
+    // It seems to be a good compromise of not wasting unused allocated space and not making too
+    // many small allocations. The AMD allocator will start making blocks at 1/8 the max size and
+    // builds up block size as needed before capping at the max set here.
     info.preferredLargeHeapBlockSize = 4*1024*1024;
     info.pAllocationCallbacks = nullptr;
     info.pDeviceMemoryCallbacks = nullptr;