diff --git a/core/hakmem_tiny_superslab_constants.h b/core/hakmem_tiny_superslab_constants.h
index 6155badc..603350a3 100644
--- a/core/hakmem_tiny_superslab_constants.h
+++ b/core/hakmem_tiny_superslab_constants.h
@@ -9,18 +9,27 @@
 // SuperSlab Layout Constants
 // ============================================================================
 
-// Log2 range for SuperSlab sizes (in MB):
-//  - MIN:  1MB (2^20)
-//  - MAX:  2MB (2^21)
-//  - DEFAULT: 2MB unless constrained by ACE/env
+// Log2 range for SuperSlab sizes:
+//  - MIN:  512KB (2^19) - Phase 2 optimization: reduced from 1MB
+//  - MAX:  2MB (2^21)   - unchanged
+//  - DEFAULT: 512KB (2^19) - Phase 2 optimization: reduced from 2MB
+//
+// Phase 2-Opt2: Reduce SuperSlab size to minimize initialization cost
+// Benefit: 75% reduction in allocation size (2MB → 512KB)
+// Expected: +3-5% throughput improvement
+// Rationale:
+//   - Smaller SuperSlab = fewer page faults during allocation
+//   - Better memory granularity (less wasted VA space)
+//   - Memset already removed in Phase 1, so pure allocation overhead
+//   - Perf analysis showed shared_pool_acquire_slab at 23.83% CPU time
 #ifndef SUPERSLAB_LG_MIN
-#define SUPERSLAB_LG_MIN 20
+#define SUPERSLAB_LG_MIN 19
 #endif
 #ifndef SUPERSLAB_LG_MAX
 #define SUPERSLAB_LG_MAX 21
 #endif
 #ifndef SUPERSLAB_LG_DEFAULT
-#define SUPERSLAB_LG_DEFAULT 21
+#define SUPERSLAB_LG_DEFAULT 19
 #endif
 
 // Size of each slab within SuperSlab (fixed, never changes)