diff --git a/src/header/TransferBench.hpp b/src/header/TransferBench.hpp
index fa536155..3b14521e 100644
--- a/src/header/TransferBench.hpp
+++ b/src/header/TransferBench.hpp
@@ -5383,9 +5383,15 @@ static bool IsConfiguredGid(union ibv_gid const& gid)
         if (cfg.general.recordPerIteration) {
           rss.perIterMsec.push_back(deltaMsec);
           std::set<std::pair<int,int>> CUs;
+          // Copy subExecutor parameters back to host before reading them.
+          // subExecParamGpuPtr lives in device memory and is not guaranteed to be host-accessible
+          // (e.g. GPUs without large/resizable BAR), so dereferencing it directly can segfault.
+          std::vector<SubExecParam> subExecParamHost(numSubExecs);
+          ERR_CHECK(hipMemcpy(subExecParamHost.data(), rss.subExecParamGpuPtr,
+                              numSubExecs * sizeof(SubExecParam), hipMemcpyDefault));
           for (int i = 0; i < numSubExecs; i++) {
-            CUs.insert(std::make_pair(rss.subExecParamGpuPtr[i].xccId,
-                                      GetId(rss.subExecParamGpuPtr[i].hwId)));
+            CUs.insert(std::make_pair(subExecParamHost[i].xccId,
+                                      GetId(subExecParamHost[i].hwId)));
           }
           rss.perIterCUs.push_back(CUs);
         }
@@ -5452,6 +5458,13 @@ static bool IsConfiguredGid(union ibv_gid const& gid)
       // If Transfers were combined into a single launch, figure out per-Transfer timing
       // Determine timing for each of the individual transfers that were part of this launch
       if (!cfg.gfx.useMultiStream) {
+        // Copy subExecutor parameters back to host before reading timing data.
+        // subExecParamGpu lives in device memory and is not guaranteed to be host-accessible
+        // (e.g. GPUs without large/resizable BAR), so dereferencing it directly can segfault.
+        std::vector<SubExecParam> subExecParamHost(exeInfo.totalSubExecs);
+        ERR_CHECK(hipMemcpy(subExecParamHost.data(), exeInfo.subExecParamGpu,
+                            exeInfo.totalSubExecs * sizeof(SubExecParam), hipMemcpyDefault));
+
         for (int i = 0; i < exeInfo.resources.size(); i++) {
           TransferResources& rss = exeInfo.resources[i];
           int64_t minStartCycle = std::numeric_limits<int64_t>::max();
@@ -5459,11 +5472,11 @@ static bool IsConfiguredGid(union ibv_gid const& gid)
           std::set<std::pair<int, int>> CUs;
 
           for (auto subExecIdx : rss.subExecIdx) {
-            minStartCycle = std::min(minStartCycle, exeInfo.subExecParamGpu[subExecIdx].startCycle);
-            maxStopCycle  = std::max(maxStopCycle,  exeInfo.subExecParamGpu[subExecIdx].stopCycle);
+            minStartCycle = std::min(minStartCycle, subExecParamHost[subExecIdx].startCycle);
+            maxStopCycle  = std::max(maxStopCycle,  subExecParamHost[subExecIdx].stopCycle);
             if (cfg.general.recordPerIteration) {
-              CUs.insert(std::make_pair(exeInfo.subExecParamGpu[subExecIdx].xccId,
-                                        GetId(exeInfo.subExecParamGpu[subExecIdx].hwId)));
+              CUs.insert(std::make_pair(subExecParamHost[subExecIdx].xccId,
+                                        GetId(subExecParamHost[subExecIdx].hwId)));
             }
           }