diff --git a/src/engine/platform/amiga.cpp b/src/engine/platform/amiga.cpp
index c97624c54..a4e279dad 100644
--- a/src/engine/platform/amiga.cpp
+++ b/src/engine/platform/amiga.cpp
@@ -80,7 +80,7 @@ const char** DivPlatformAmiga::getRegisterSheet() {
   }
 
 void DivPlatformAmiga::acquire(short** buf, size_t len) {
-  static int outL, outR, output;
+  thread_local int outL, outR, output;
   for (size_t h=0; h<len; h++) {
     bool hsync=bypassLimits;
     outL=0;
diff --git a/src/engine/platform/arcade.cpp b/src/engine/platform/arcade.cpp
index 3e09dfbe1..26ad689a1 100644
--- a/src/engine/platform/arcade.cpp
+++ b/src/engine/platform/arcade.cpp
@@ -52,7 +52,7 @@ const char** DivPlatformArcade::getRegisterSheet() {
 }
 
 void DivPlatformArcade::acquire_nuked(short** buf, size_t len) {
-  static int o[2];
+  thread_local int o[2];
 
   for (size_t h=0; h<len; h++) {
     for (int i=0; i<8; i++) {
@@ -92,7 +92,7 @@ void DivPlatformArcade::acquire_nuked(short** buf, size_t len) {
 }
 
 void DivPlatformArcade::acquire_ymfm(short** buf, size_t len) {
-  static int os[2];
+  thread_local int os[2];
 
   ymfm::ym2151::fm_engine* fme=fm_ymfm->debug_engine();
 
diff --git a/src/engine/platform/genesis.cpp b/src/engine/platform/genesis.cpp
index 1564fa0cc..4973a323d 100644
--- a/src/engine/platform/genesis.cpp
+++ b/src/engine/platform/genesis.cpp
@@ -132,8 +132,8 @@ void DivPlatformGenesis::processDAC(int iRate) {
 }
 
 void DivPlatformGenesis::acquire_nuked(short** buf, size_t len) {
-  static short o[2];
-  static int os[2];
+  thread_local short o[2];
+  thread_local int os[2];
 
   for (size_t h=0; h<len; h++) {
     processDAC(rate);
@@ -213,7 +213,7 @@ void DivPlatformGenesis::acquire_nuked(short** buf, size_t len) {
 }
 
 void DivPlatformGenesis::acquire_ymfm(short** buf, size_t len) {
-  static int os[2];
+  thread_local int os[2];
 
   ymfm::ym2612::fm_engine* fme=fm_ymfm->debug_engine();
 
diff --git a/src/engine/platform/opl.cpp b/src/engine/platform/opl.cpp
index dff366d32..44e9b3b14 100644
--- a/src/engine/platform/opl.cpp
+++ b/src/engine/platform/opl.cpp
@@ -160,9 +160,9 @@ const int orderedOpsL[4]={
 #define ADDR_LR_FB_ALG 0xc0
 
 void DivPlatformOPL::acquire_nuked(short** buf, size_t len) {
-  static short o[4];
-  static int os[4];
-  static ymfm::ymfm_output<2> aOut;
+  thread_local short o[4];
+  thread_local int os[4];
+  thread_local ymfm::ymfm_output<2> aOut;
 
   for (size_t h=0; h<len; h++) {
     os[0]=0; os[1]=0; os[2]=0; os[3]=0;
diff --git a/src/engine/platform/opll.cpp b/src/engine/platform/opll.cpp
index 1c7dc72e1..3f1621c02 100644
--- a/src/engine/platform/opll.cpp
+++ b/src/engine/platform/opll.cpp
@@ -43,8 +43,8 @@ const unsigned char visMapOPLL[9]={
 };
 
 void DivPlatformOPLL::acquire_nuked(short** buf, size_t len) {
-  static int o[2];
-  static int os;
+  thread_local int o[2];
+  thread_local int os;
 
   for (size_t h=0; h<len; h++) {
     os=0;
diff --git a/src/engine/platform/segapcm.cpp b/src/engine/platform/segapcm.cpp
index 5e584e016..f81dbc487 100644
--- a/src/engine/platform/segapcm.cpp
+++ b/src/engine/platform/segapcm.cpp
@@ -27,7 +27,7 @@
 #define chWrite(c,a,v) rWrite(((c)<<3)+(a),v)
 
 void DivPlatformSegaPCM::acquire(short** buf, size_t len) {
-  static int os[2];
+  thread_local int os[2];
 
   for (size_t h=0; h<len; h++) {
     while (!writes.empty()) {
diff --git a/src/engine/platform/tx81z.cpp b/src/engine/platform/tx81z.cpp
index 540365cde..a8f3a2f46 100644
--- a/src/engine/platform/tx81z.cpp
+++ b/src/engine/platform/tx81z.cpp
@@ -58,7 +58,7 @@ const char** DivPlatformTX81Z::getRegisterSheet() {
 }
 
 void DivPlatformTX81Z::acquire(short** buf, size_t len) {
-  static int os[2];
+  thread_local int os[2];
 
   ymfm::ym2414::fm_engine* fme=fm_ymfm->debug_engine();
 
diff --git a/src/engine/platform/ym2203.cpp b/src/engine/platform/ym2203.cpp
index 2e805f3cd..53d2cfe06 100644
--- a/src/engine/platform/ym2203.cpp
+++ b/src/engine/platform/ym2203.cpp
@@ -165,8 +165,8 @@ void DivPlatformYM2203::acquire(short** buf, size_t len) {
 }
 
 void DivPlatformYM2203::acquire_combo(short** buf, size_t len) {
-  static int os;
-  static short ignored[2];
+  thread_local int os;
+  thread_local short ignored[2];
 
   for (size_t h=0; h<len; h++) {
     // AY -> OPN
@@ -241,7 +241,7 @@ void DivPlatformYM2203::acquire_combo(short** buf, size_t len) {
 }
 
 void DivPlatformYM2203::acquire_ymfm(short** buf, size_t len) {
-  static int os;
+  thread_local int os;
 
   ymfm::ym2203::fm_engine* fme=fm->debug_fm_engine();
 
diff --git a/src/engine/platform/ym2608.cpp b/src/engine/platform/ym2608.cpp
index dcab9dd5f..743cfab46 100644
--- a/src/engine/platform/ym2608.cpp
+++ b/src/engine/platform/ym2608.cpp
@@ -306,8 +306,8 @@ void DivPlatformYM2608::acquire(short** buf, size_t len) {
 }
 
 void DivPlatformYM2608::acquire_combo(short** buf, size_t len) {
-  static int os[2];
-  static short ignored[2];
+  thread_local int os[2];
+  thread_local short ignored[2];
 
   ymfm::ssg_engine* ssge=fm->debug_ssg_engine();
   ymfm::adpcm_a_engine* aae=fm->debug_adpcm_a_engine();
@@ -419,7 +419,7 @@ void DivPlatformYM2608::acquire_combo(short** buf, size_t len) {
 }
 
 void DivPlatformYM2608::acquire_ymfm(short** buf, size_t len) {
-  static int os[2];
+  thread_local int os[2];
 
   ymfm::ym2608::fm_engine* fme=fm->debug_fm_engine();
   ymfm::ssg_engine* ssge=fm->debug_ssg_engine();
diff --git a/src/engine/platform/ym2610.cpp b/src/engine/platform/ym2610.cpp
index 8b9295d9f..173d882a6 100644
--- a/src/engine/platform/ym2610.cpp
+++ b/src/engine/platform/ym2610.cpp
@@ -241,8 +241,8 @@ void DivPlatformYM2610::acquire(short** buf, size_t len) {
 }
 
 void DivPlatformYM2610::acquire_combo(short** buf, size_t len) {
-  static int os[2];
-  static short ignored[2];
+  thread_local int os[2];
+  thread_local short ignored[2];
 
   ymfm::ssg_engine* ssge=fm->debug_ssg_engine();
   ymfm::adpcm_a_engine* aae=fm->debug_adpcm_a_engine();
@@ -350,7 +350,7 @@ void DivPlatformYM2610::acquire_combo(short** buf, size_t len) {
 }
 
 void DivPlatformYM2610::acquire_ymfm(short** buf, size_t len) {
-  static int os[2];
+  thread_local int os[2];
 
   ymfm::ym2610::fm_engine* fme=fm->debug_fm_engine();
   ymfm::ssg_engine* ssge=fm->debug_ssg_engine();
diff --git a/src/engine/platform/ym2610b.cpp b/src/engine/platform/ym2610b.cpp
index 7369265f9..4f00a7761 100644
--- a/src/engine/platform/ym2610b.cpp
+++ b/src/engine/platform/ym2610b.cpp
@@ -305,8 +305,8 @@ void DivPlatformYM2610B::acquire(short** buf, size_t len) {
 }
 
 void DivPlatformYM2610B::acquire_combo(short** buf, size_t len) {
-  static int os[2];
-  static short ignored[2];
+  thread_local int os[2];
+  thread_local short ignored[2];
 
   ymfm::ssg_engine* ssge=fm->debug_ssg_engine();
   ymfm::adpcm_a_engine* aae=fm->debug_adpcm_a_engine();
@@ -418,7 +418,7 @@ void DivPlatformYM2610B::acquire_combo(short** buf, size_t len) {
 }
 
 void DivPlatformYM2610B::acquire_ymfm(short** buf, size_t len) {
-  static int os[2];
+  thread_local int os[2];
 
   ymfm::ym2610b::fm_engine* fme=fm->debug_fm_engine();
   ymfm::ssg_engine* ssge=fm->debug_ssg_engine();
diff --git a/src/engine/playback.cpp b/src/engine/playback.cpp
index 1cb7b62d8..7582c9efb 100644
--- a/src/engine/playback.cpp
+++ b/src/engine/playback.cpp
@@ -2115,8 +2115,12 @@ void DivEngine::nextBuf(float** in, float** out, int inChans, int outChans, unsi
         logW("%d: size<lastAvail! %d<%d",i,size,disCont[i].lastAvail);
         continue;
       }
-      disCont[i].fillBuf(disCont[i].runtotal,disCont[i].lastAvail,size-disCont[i].lastAvail);
+      renderPool->push([](void* d) {
+        DivDispatchContainer* dc=(DivDispatchContainer*)d;
+        dc->fillBuf(dc->runtotal,dc->lastAvail,dc->size-dc->lastAvail);
+      },&disCont[i]);
     }
+    renderPool->wait();
   }
 
   if (metroBufLen<size || metroBuf==NULL) {
diff --git a/src/engine/workPool.cpp b/src/engine/workPool.cpp
index 005645ee5..f871eab82 100644
--- a/src/engine/workPool.cpp
+++ b/src/engine/workPool.cpp
@@ -41,7 +41,7 @@ void DivWorkThread::run() {
       if (setFuckingPromise) {
         parent->notify.set_value();
         setFuckingPromise=false;
-        std::this_thread::yield();
+        //std::this_thread::yield();
       }
       if (terminate) {
         break;
@@ -153,7 +153,7 @@ void DivWorkPool::wait() {
       }
     }
   }
-  std::this_thread::yield();
+  //std::this_thread::yield();
 
   // wait
   future.wait();
diff --git a/src/gui/settings.cpp b/src/gui/settings.cpp
index 9d1cc14b1..5d49c021e 100644
--- a/src/gui/settings.cpp
+++ b/src/gui/settings.cpp
@@ -902,7 +902,7 @@ void FurnaceGUI::drawSettings() {
             }
           }
           if (ImGui::IsItemHovered()) {
-            ImGui::SetTooltip("runs chip emulation on separate threads.\nmay increase performance on multi-core CPUs.\n\nwarnings:\n- experimental! currently broken/not working well.\n- only useful on multi-chip songs.");
+            ImGui::SetTooltip("runs chip emulation on separate threads.\nmay increase performance when using heavy emulation cores.\n\nwarnings:\n- experimental!\n- only useful on multi-chip songs.");
           }
 
           if (renderPoolThreadsB) {