diff --git a/src/device/common.h b/src/device/common.h
index 2ac5511c19..cf6edba321 100644
--- a/src/device/common.h
+++ b/src/device/common.h
@@ -27,17 +27,30 @@
 #endif
 
 #if defined(__gfx1100__) || defined(__gfx1101__) || defined(__gfx1102__) || defined(__gfx1200__) || defined(__gfx1201__)
-#define __trace_hwreg()
+#define __trace_hwreg() \
+  collTrace->data_0 = 0;
 #else
 #define __trace_hwreg() \
-  asm volatile ("s_getreg_b32 %0, hwreg(HW_REG_HW_ID)" : "=s" (collTrace->data_0));
+  { int32_t hwid; \
+    asm volatile ("s_getreg_b32 %0, hwreg(HW_REG_HW_ID)" : "=s" (hwid)); \
+    collTrace->data_0 = hwid >> 4; }
 #endif
+
+#if defined(__gfx942__) || defined(__gfx950__)
+#define __trace_xccid() \
+  { int32_t xccId; \
+    asm volatile ("s_getreg_b32 %0, hwreg(HW_REG_XCC_ID)" : "=s" (xccId)); \
+    collTrace->xccId = xccId; }
+#else
+#define __trace_xccid() \
+  collTrace->xccId = 0;
+#endif
+
 #ifdef ENABLE_COLLTRACE
   #define INC_COLL_TRACE \
     uint32_t pos = __hip_atomic_fetch_add(&ncclShmem.collTraceTail->tail, 1, __ATOMIC_SEQ_CST, __HIP_MEMORY_SCOPE_WORKGROUP)%COLLTRACE_NUM_ITEMS; \
     struct ncclCollTrace* collTrace = ncclShmem.collTrace+pos; \
     collTrace->timeStamp = wall_clock64(); \
-    collTrace->bid = blockIdx.x; \
     collTrace->tid = threadIdx.x; \
     collTrace->channelId = ncclShmem.channelId;
     // TODO: switch to atomicInc after llvm crash is fixed
@@ -46,7 +59,8 @@
   #define traceKernelLaunch(launch_type, ix) { \
     INC_COLL_TRACE \
     collTrace->funcIndex = ncclShmem.funcId; \
-    __trace_hwreg()\
+    __trace_hwreg() \
+    __trace_xccid() \
     collTrace->batchIx = ix; \
     if (ncclShmem.workType == ncclDevWorkTypeP2p) { \
       struct ncclDevWorkP2p *p2pWork = (struct ncclDevWorkP2p*)ncclShmem.workStorage; \
@@ -63,7 +77,7 @@
       collTrace->p2p.recvRegistered = p2pWork->recvNetReg; \
       collTrace->p2pOpCount[0] = p2pWork->sendOpCount; \
       collTrace->p2pOpCount[1] = p2pWork->recvOpCount; \
-      collTrace->type = (launch_type) | ncclCollTraceP2pElemType; \
+      __hip_atomic_store(&collTrace->type, (launch_type) | ncclCollTraceP2pElemType, __ATOMIC_RELEASE, __HIP_MEMORY_SCOPE_WORKGROUP); \
     } else if (ncclShmem.workType == ncclDevWorkTypeColl) { \
       struct ncclDevWorkColl *collWork = (struct ncclDevWorkColl*)ncclShmem.workStorage; \
       collTrace->coll.nWarps = collWork->nWarps; \
@@ -71,7 +85,7 @@
       collTrace->coll.bid = ncclShmem.channelId - collWork->channelLo; \
       collTrace->coll.root = collWork->root; \
       collTrace->opCount = collWork->opCount; \
-      collTrace->type = (launch_type) | ncclCollTraceCollElemType; \
+      __hip_atomic_store(&collTrace->type, (launch_type) | ncclCollTraceCollElemType, __ATOMIC_RELEASE, __HIP_MEMORY_SCOPE_WORKGROUP); \
     } \
   }
   #define traceKernelEnd(end_type)  { \
@@ -81,11 +95,11 @@
       struct ncclDevWorkP2p *p2pWork = (struct ncclDevWorkP2p*)ncclShmem.workStorage; \
       collTrace->p2pOpCount[0] = p2pWork->sendOpCount; \
       collTrace->p2pOpCount[1] = p2pWork->recvOpCount; \
-      collTrace->type = (end_type) | ncclCollTraceP2pElemType; \
+      __hip_atomic_store(&collTrace->type, (end_type) | ncclCollTraceP2pElemType, __ATOMIC_RELEASE, __HIP_MEMORY_SCOPE_WORKGROUP); \
     } else if (ncclShmem.workType == ncclDevWorkTypeColl) { \
       struct ncclDevWorkColl *collWork = (struct ncclDevWorkColl*)ncclShmem.workStorage; \
       collTrace->opCount = collWork->opCount; \
-      collTrace->type = (end_type) | ncclCollTraceCollElemType; \
+      __hip_atomic_store(&collTrace->type, (end_type) | ncclCollTraceCollElemType, __ATOMIC_RELEASE, __HIP_MEMORY_SCOPE_WORKGROUP); \
     } \
   }
   #define traceData(data2, data4, data8_0, data8_1) { \
@@ -94,12 +108,12 @@
     collTrace->data_0 = data4; \
     collTrace->opCount = data8_0; \
     collTrace->data_1 = data8_1; \
-    collTrace->type = ncclCollTraceDataType; \
+    __hip_atomic_store(&collTrace->type, ncclCollTraceDataType, __ATOMIC_RELEASE, __HIP_MEMORY_SCOPE_WORKGROUP); \
   }
   #define traceAbort(){\
     INC_COLL_TRACE\
     collTrace->funcIndex = ncclShmem.funcId;\
-    collTrace->type = ncclCollTraceAbortType;\
+    __hip_atomic_store(&collTrace->type, ncclCollTraceAbortType, __ATOMIC_RELEASE, __HIP_MEMORY_SCOPE_WORKGROUP); \
   }
 #else
 #define traceKernelLaunch(launch_type, batchIx)
diff --git a/src/enqueue.cc b/src/enqueue.cc
index 284856b7ff..578dc44538 100644
--- a/src/enqueue.cc
+++ b/src/enqueue.cc
@@ -684,6 +684,10 @@ static ncclResult_t scheduleCollTasksToPlan(
   size_t trafficPerChannel = 0;
   int channelId = 0;
   size_t currentTraffic = 0;
+
+  size_t channelCounts[MAXCHANNELS];
+  for (int c=0; c<MAXCHANNELS; c++) channelCounts[c] = 0;
+
   while (nPlanColls!=0 && !ncclIntruQueueEmpty(&planner->collTaskQueue)) {
     struct ncclTaskColl* task = ncclIntruQueueHead(&planner->collTaskQueue);
     struct ncclWorkList* workNode = ncclIntruQueueHead(&planner->collWorkQueue);
@@ -916,6 +920,10 @@ static ncclResult_t scheduleCollTasksToPlan(
           int(devWork->cbd.chunkGrainsLo*rcclProtoGrainSize(task->protocol, comm)),
           int(devWork->cbd.chunkGrainsMid*rcclProtoGrainSize(task->protocol, comm)),
           int(devWork->cbd.chunkGrainsHi*rcclProtoGrainSize(task->protocol, comm)));
+          // channel traffic counter
+          channelCounts[devWork->channelLo] += (long)devWork->cbd.countLo;
+          if (devWork->channelLo != devWork->channelHi) channelCounts[devWork->channelHi] += (long)devWork->cbd.countHi;
+          for (int c=devWork->channelLo+1; c<devWork->channelHi; c++) channelCounts[c] += (long)devWork->cbd.countMid;
       }
     }
 
@@ -930,6 +938,15 @@ static ncclResult_t scheduleCollTasksToPlan(
     ncclIntruQueueEnqueue(&plan->workQueue, workNode);
     plan->workBytes += workNode->size;
   }
+
+  char line[1024];
+  int offset = 0;
+  for (int c=0; c<MAXCHANNELS; c++) {
+    sprintf(line+offset, "%ld ", channelCounts[c]);
+    offset = strlen(line);
+  }
+  TRACE(NCCL_COLL, "Channel traffic counts: %s", line);
+
   return ncclSuccess;
 }
 
@@ -2794,7 +2811,7 @@ ncclResult_t ncclEnqueueCheck(struct ncclInfo* info) {
   }
   NCCLCHECKGOTO(ArgsCheck(info), ret, fail);
 
-  INFO(NCCL_COLL,"%s: opCount %lx sendbuff %p recvbuff %p acc %p count %zu datatype %d op %d root %d comm %p [nranks=%d] stream %p task %d globalrank %d",
+  INFO(NCCL_COLL,"%s: opCount %lx sendbuff %p recvbuff %p acc %p count %u datatype %d op %d root %d comm %p [nranks=%d] stream %p task %d globalrank %d",
         info->opName, info->comm->opCount, info->sendbuff, info->recvbuff, info->acc, info->count,
         info->datatype, info->op, info->root, info->comm, info->comm->nRanks, info->stream,
         info->comm->planner.nTasksP2p + info->comm->planner.nTasksColl,
diff --git a/src/include/device.h b/src/include/device.h
index 91f9858dd8..6944f3921b 100644
--- a/src/include/device.h
+++ b/src/include/device.h
@@ -507,10 +507,10 @@ typedef enum {
 } ncclCollTraceDataType_t;
 
 struct ncclCollTrace {
-  uint8_t type;
-  uint8_t bid;
   int16_t funcIndex;
-  uint16_t data_0;
+  uint8_t xccId:4;
+  uint16_t data_0:12;
+  uint8_t type;
   uint8_t batchIx;
   uint8_t tid;
   uint8_t channelId;
diff --git a/src/init.cc b/src/init.cc
index 1b8d6f6513..9278d8d835 100644
--- a/src/init.cc
+++ b/src/init.cc
@@ -297,21 +297,21 @@ void *ncclCommThreadMain(void *arg) {
       }
       for (int i = 0; i < count; i++) {
         volatile struct ncclCollTrace *td = comm->collTrace+COLLTRACE_NUM_ITEMS*channel+head[channel]%COLLTRACE_NUM_ITEMS;
-        head[channel] ++;
         const uint8_t type = td->type;
         if (type == ncclCollTraceNotReady)
-          continue;
+          break;
+        head[channel] ++;
         char line[1024];
         int offset = 0;
         const uint16_t fIdx = td->funcIndex;
         if (type == ncclCollTraceDataType) {
           sprintf(line, "## [%012.6f] [%02d:%02d-%02d:%02x] L:%04d DT %08x %016lx %016lx",
-            (double)(td->timeStamp)/vega_gpu_rtc_freq, comm->rank, td->bid, td->channelId, td->tid,             fIdx, td->data_0, td->opCount, td->data_1);
+            (double)(td->timeStamp)/vega_gpu_rtc_freq, comm->rank, channel, td->channelId, td->tid, fIdx, td->data_0, td->opCount, td->data_1);
         } else {
           if (type & ncclCollTraceP2pElemType)
-            sprintf(line, "## [%012.6f] [%02d:%02d-%02d:%02x] %06x-%06x", (double)(td->timeStamp)/vega_gpu_rtc_freq, comm->rank, td->bid, td->channelId, td->tid, td->p2pOpCount[0], td->p2pOpCount[1]);
+            sprintf(line, "## [%012.6f] [%02d:%02d-%02d:%02x] %06x-%06x", (double)(td->timeStamp)/vega_gpu_rtc_freq, comm->rank, channel, td->channelId, td->tid, td->p2pOpCount[0], td->p2pOpCount[1]);
           else
-            sprintf(line, "## [%012.6f] [%02d:%02d-%02d:%02x] %06lx", (double)(td->timeStamp)/vega_gpu_rtc_freq, comm->rank, td->bid, td->channelId, td->tid, td->opCount);
+            sprintf(line, "## [%012.6f] [%02d:%02d-%02d:%02x] %06lx", (double)(td->timeStamp)/vega_gpu_rtc_freq, comm->rank, channel, td->channelId, td->tid, td->opCount);
           offset = strlen(line);
           if (type == ncclCollTraceCollElemType) {
             sprintf(line+offset, " CE %s nw %d bi %d nc %d root %d busId %lx nRanks %d", funcNames[fIdx], td->coll.nWarps, td->coll.bid, td->coll.nChannels, td->coll.root, comm->busId, comm->nRanks);
@@ -324,9 +324,9 @@ void *ncclCommThreadMain(void *arg) {
               case ncclCollTraceKernelLaunchType:
               case ncclCollTraceCollLaunchType:
                 if ((type&0xf) == ncclCollTraceKernelLaunchType)
-                  sprintf(line+offset, " KL %s [%02d:%02d-%02d:%02x] HWID %8x ", funcNames[fIdx], comm->rank, td->bid, td->channelId, td->tid, td->data_0);
+                  sprintf(line+offset, " KL %s [%02d:%02d-%02d:%02x] HWID %d:%x ", funcNames[fIdx], comm->rank, channel, td->channelId, td->tid, td->xccId, td->data_0);
                 else if ((type&0xf) == ncclCollTraceCollLaunchType)
-                  sprintf(line+offset, " CL %s [%02d:%02d-%02d:%02x] %d ", funcNames[fIdx], comm->rank, td->bid, td->channelId, td->tid, td->batchIx);
+                  sprintf(line+offset, " CL %s [%02d:%02d-%02d:%02x] %d ", funcNames[fIdx], comm->rank, channel, td->channelId, td->tid, td->batchIx);
                 offset = strlen(line);
                 if ((type&0xf0) == ncclCollTraceCollElemType)
                   sprintf(line+offset, " nw %d bi %d nc %d root %d busId %lx nRanks %d", td->coll.nWarps, td->coll.bid, td->coll.nChannels, td->coll.root, comm->busId, comm->nRanks);
@@ -336,10 +336,10 @@ void *ncclCommThreadMain(void *arg) {
                     comm->busId, comm->nRanks);
                 break;
               case ncclCollTraceKernelEndType:
-                sprintf(line+offset, " KE %s [%02d:%02d-%02d:%02x] busId %lx nRanks %d", funcNames[fIdx], comm->rank, td->bid, td->channelId, td->tid, comm->busId, comm->nRanks);
+                sprintf(line+offset, " KE %s [%02d:%02d-%02d:%02x] busId %lx nRanks %d", funcNames[fIdx], comm->rank, channel, td->channelId, td->tid, comm->busId, comm->nRanks);
                 break;
               case ncclCollTraceAbortType:
-                sprintf(line+offset, " KA %s [%02d:%02d-%02d:%02x]", funcNames[fIdx], comm->rank, td->bid, td->channelId, td->tid);
+                sprintf(line+offset, " KA %s [%02d:%02d-%02d:%02x]", funcNames[fIdx], comm->rank, channel, td->channelId, td->tid);
                 break;
               default:
                 sprintf(line+offset, " unknown collective trace data type");
@@ -348,7 +348,9 @@ void *ncclCommThreadMain(void *arg) {
           }
         }
         INFO(NCCL_COLL, "%s td->type:%d", line, type);
-        td->type = ncclCollTraceNotReady;
+        volatile uint8_t *tdtype = &td->type;
+        *tdtype = ncclCollTraceNotReady;
+        (*tdtype); // read back for flushing
       }
     }
     if (comm->collTraceExit && numActiveChans == 0)
@@ -477,7 +479,7 @@ static ncclResult_t commFree(ncclComm_t comm) {
       ncclCommThreadMain((void *)comm);
   }
   NCCLCHECK(ncclCudaFree((void *)comm->collTrace));
-  NCCLCHECK(ncclCudaFree((void *)comm->collTraceTail));
+  NCCLCHECK(ncclCudaHostFree((void *)comm->collTraceTail));
 #endif
 
   free(comm->peerInfo);
@@ -678,8 +680,12 @@ static ncclResult_t commAlloc(struct ncclComm* comm, struct ncclComm* parent, in
   comm->dmaBufSupport = (dmaBufSupported(comm) == ncclSuccess) ? true : false;
 
 #ifdef ENABLE_COLLTRACE
-  NCCLCHECK(ncclCudaCalloc(&comm->collTraceTail, MAXCHANNELS));
+  NCCLCHECK(ncclCudaHostCalloc(&comm->collTraceTail, MAXCHANNELS));
+#if defined(HIP_UNCACHED_MEMORY)
+  NCCLCHECK(ncclCudaCalloc(&comm->collTrace, COLLTRACE_NUM_ITEMS*MAXCHANNELS, nullptr, hipDeviceMallocUncached));
+#else
   NCCLCHECK(ncclCudaCalloc(&comm->collTrace, COLLTRACE_NUM_ITEMS*MAXCHANNELS));
+#endif
   comm->collTraceExit = 0;
   comm->collTraceEnabled = false; // we can enable colltrace without starting a thread
   if ((ncclDebugLevel >= NCCL_LOG_INFO) && rcclParamKernelCollTraceEnable()) {