diff --git a/src/amd/compiler/aco_live_var_analysis.cpp b/src/amd/compiler/aco_live_var_analysis.cpp
index 0378dbaf335..08f2d68c80a 100644
--- a/src/amd/compiler/aco_live_var_analysis.cpp
+++ b/src/amd/compiler/aco_live_var_analysis.cpp
@@ -337,6 +337,8 @@ void update_vgpr_sgpr_demand(Program* program, const RegisterDemand new_demand)
 {
    /* TODO: max_waves_per_simd, simd_per_cu and the number of physical vgprs for Navi */
    unsigned max_waves_per_simd = 10;
+   if ((program->family >= CHIP_POLARIS10 && program->family <= CHIP_VEGAM) || program->chip_class >= GFX10_3)
+      max_waves_per_simd = 8;
    unsigned simd_per_cu = 4;
 
    bool wgp = program->chip_class >= GFX10; /* assume WGP is used on Navi */
diff --git a/src/amd/compiler/aco_scheduler.cpp b/src/amd/compiler/aco_scheduler.cpp
index 102f0bf3ee6..40941e4c539 100644
--- a/src/amd/compiler/aco_scheduler.cpp
+++ b/src/amd/compiler/aco_scheduler.cpp
@@ -882,6 +882,11 @@ void schedule_block(sched_ctx& ctx, Program *program, Block* block, live& live_v
 
 void schedule_program(Program *program, live& live_vars)
 {
+   /* don't use program->max_reg_demand because that is affected by max_waves_per_simd */
+   RegisterDemand demand;
+   for (Block& block : program->blocks)
+      demand.update(block.register_demand);
+
    sched_ctx ctx;
    ctx.mv.depends_on.resize(program->peekAllocationId());
    ctx.mv.RAR_dependencies.resize(program->peekAllocationId());
@@ -891,15 +896,14 @@ void schedule_program(Program *program, live& live_vars)
     * seem to hurt anything else. */
    if (program->num_waves <= 5)
       ctx.num_waves = program->num_waves;
-   else if (program->max_reg_demand.vgpr >= 32)
+   else if (demand.vgpr >= 29)
       ctx.num_waves = 5;
-   else if (program->max_reg_demand.vgpr >= 28)
+   else if (demand.vgpr >= 25)
       ctx.num_waves = 6;
-   else if (program->max_reg_demand.vgpr >= 24)
-      ctx.num_waves = 7;
    else
-      ctx.num_waves = 8;
+      ctx.num_waves = 7;
    ctx.num_waves = std::max<uint16_t>(ctx.num_waves, program->min_waves);
+   ctx.num_waves = std::min<uint16_t>(ctx.num_waves, program->max_waves);
 
    assert(ctx.num_waves > 0 && ctx.num_waves <= program->num_waves);
    ctx.mv.max_registers = { int16_t(get_addr_vgpr_from_waves(program, ctx.num_waves) - 2),