diff --git a/src/pcm-raw.cpp b/src/pcm-raw.cpp
index a92751e3..8bfdd02b 100644
--- a/src/pcm-raw.cpp
+++ b/src/pcm-raw.cpp
@@ -1877,10 +1877,11 @@ void printTransposed(const PCM::RawPMUConfigs& curPMUConfigs,
             }
             else if (type == "ubox")
             {
+                const auto numPMUs = (uint32)m->getMaxNumOfUncorePMUs(PCM::UBOX_PMU_ID);
                 choose(outputType,
-                    [&]() { printUncoreRows(nullptr, 1U, ""); },
-                    [&]() { printUncoreRows(nullptr, 1U, type); },
-                    [&]() { printUncoreRows([](const uint32, const uint32 i, const ServerUncoreCounterState& before, const ServerUncoreCounterState& after) { return getUncoreCounter(PCM::UBOX_PMU_ID, 0, i, before, after); }, 1U,
+                    [&]() { printUncoreRows(nullptr, numPMUs, ""); },
+                    [&]() { printUncoreRows(nullptr, numPMUs, type); },
+                    [&]() { printUncoreRows([](const uint32 u, const uint32 i, const ServerUncoreCounterState& before, const ServerUncoreCounterState& after) { return getUncoreCounter(PCM::UBOX_PMU_ID, u, i, before, after); }, numPMUs,
                             "UncoreClocks", [](const uint32, const ServerUncoreCounterState& before, const ServerUncoreCounterState& after) { return getUncoreClocks(before, after); });
                     });
             }
@@ -2260,14 +2261,17 @@ void print(const PCM::RawPMUConfigs& curPMUConfigs,
                         [&fixedEvents]() { cout << "UncoreClocks" << fixedEvents[0].second << separator; },
                         [&]() { cout << getUncoreClocks(BeforeUncoreState[s], AfterUncoreState[s]) << separator; });
                 }
-                int i = 0;
-                for (auto& event : events)
+                for (uint32 u = 0; u < m->getMaxNumOfUncorePMUs(PCM::UBOX_PMU_ID); ++u)
                 {
-                    choose(outputType,
-                        [s]() { cout << "SKT" << s << separator; },
-                        [&event, &i]() { if (event.second.empty()) cout << "UBOXEvent" << i << separator;  else cout << event.second << separator; },
-                        [&]() { cout << getUncoreCounter(PCM::UBOX_PMU_ID, 0, i, BeforeUncoreState[s], AfterUncoreState[s]) << separator; });
-                    ++i;
+                    int i = 0;
+                    for (auto& event : events)
+                    {
+                        choose(outputType,
+                            [s, u]() { cout << "SKT" << s << "U" << u << separator; },
+                            [&event, &i]() { if (event.second.empty()) cout << "UBOXEvent" << i << separator;  else cout << event.second << separator; },
+                            [&]() { cout << getUncoreCounter(PCM::UBOX_PMU_ID, u, i, BeforeUncoreState[s], AfterUncoreState[s]) << separator; });
+                        ++i;
+                    }
                 }
             }
         }
diff --git a/src/uncore_pmu_discovery.cpp b/src/uncore_pmu_discovery.cpp
index 62e47516..fd968ef4 100644
--- a/src/uncore_pmu_discovery.cpp
+++ b/src/uncore_pmu_discovery.cpp
@@ -15,35 +15,74 @@ UncorePMUDiscovery::UncorePMUDiscovery()
     {
         return;
     }
-    auto processTables = [this](const uint64 bar, const VSEC &)
+    const auto debug = (safe_getenv("PCM_DEBUG_PMU_DISCOVERY") == std::string("1"));
+
+    auto processTables = [this, &debug](const uint64 bar, const VSEC & vsec)
     {
-        constexpr size_t UncoreDiscoverySize = 3UL;
-        union UncoreGlobalDiscovery {
-            GlobalPMU pmu;
-            uint64 table[UncoreDiscoverySize];
-        };
-        UncoreGlobalDiscovery global;
-        mmio_memcpy(global.table, bar, UncoreDiscoverySize * sizeof(uint64), true);
-        globalPMUs.push_back(global.pmu);
-        union UncoreUnitDiscovery {
-            BoxPMU pmu;
-            uint64 table[UncoreDiscoverySize];
-        };
-        UncoreUnitDiscovery unit;
-        const auto step = global.pmu.stride * 8;
-        BoxPMUMap boxPMUMap;
-        for (size_t u = 0; u < global.pmu.maxUnits; ++u)
-        {
-            mmio_memcpy(unit.table, bar + (u+1) * step, UncoreDiscoverySize * sizeof(uint64), true);
-            if (unit.table[0] == 0 && unit.table[1] == 0)
+        try {
+            DBG(2, "Uncore discovery detection. Reading from bar 0x", std::hex, bar, std::dec);
+            constexpr size_t UncoreDiscoverySize = 3UL;
+            union UncoreGlobalDiscovery {
+                GlobalPMU pmu;
+                uint64 table[UncoreDiscoverySize];
+            };
+            UncoreGlobalDiscovery global;
+            mmio_memcpy(global.table, bar, UncoreDiscoverySize * sizeof(uint64), true);
+            globalPMUs.push_back(global.pmu);
+            if (debug)
             {
-                // invalid entry
-                continue;
+                std::cerr << "Read global.pmu from 0x" << std::hex << bar << std::dec << "\n";
+                global.pmu.print();
+                std::cout.flush();
+            }
+            union UncoreUnitDiscovery {
+                BoxPMU pmu;
+                uint64 table[UncoreDiscoverySize];
+            };
+            UncoreUnitDiscovery unit;
+            const auto step = global.pmu.stride * 8;
+            BoxPMUMap boxPMUMap;
+            for (size_t u = 0; u < global.pmu.maxUnits; ++u)
+            {
+                mmio_memcpy(unit.table, bar + (u + 1) * step, UncoreDiscoverySize * sizeof(uint64), true);
+                if (debug)
+                {
+                    std::cerr << "Read unit.pmu " << u << " from 0x" << std::hex << (bar + (u + 1) * step) << std::dec << "\n";
+                    unit.pmu.print();
+                    std::cout.flush();
+                }
+                if (unit.table[0] == 0 && unit.table[1] == 0)
+                {
+                    if (debug)
+                    {
+                        std::cerr << "Invalid entry\n";
+                    }
+                    // invalid entry
+                    continue;
+                }
+                // unit.pmu.print();
+                boxPMUMap[unit.pmu.boxType].push_back(unit.pmu);
             }
-            // unit.pmu.print();
-            boxPMUMap[unit.pmu.boxType].push_back(unit.pmu);
+            boxPMUs.push_back(boxPMUMap);
+        }
+        catch (const std::exception & e)
+        {
+            std::cerr << "WARNING: enumeration of devices in UncorePMUDiscovery failed on bar 0x"
+                << std::hex << bar << "\n" << e.what() << "\n" <<
+                " CAP_ID: 0x" << vsec.fields.cap_id << "\n" <<
+                " CAP_VERSION: 0x" << vsec.fields.cap_version << "\n" <<
+                " CAP_NEXT: 0x" << vsec.fields.cap_next << "\n" <<
+                " VSEC_ID: 0x" << vsec.fields.vsec_id << "\n" <<
+                " VSEC_VERSION: 0x" << vsec.fields.vsec_version << "\n" <<
+                " VSEC_LENGTH: 0x" << vsec.fields.vsec_length << "\n" <<
+                " ENTRY_ID: 0x" << vsec.fields.entryID << "\n" <<
+                " NUM_ENTRIES: 0x" << vsec.fields.NumEntries << "\n" <<
+                " ENTRY_SIZE: 0x" << vsec.fields.EntrySize << "\n" <<
+                " TBIR: 0x" << vsec.fields.tBIR << "\n" <<
+                " ADDRESS: 0x" << vsec.fields.Address <<
+                std::dec << "\n";
+            std::cerr << "INFO: discovery has " << boxPMUs.size() << " entries\n";
         }
-        boxPMUs.push_back(boxPMUMap);
     };
     try {
         processDVSEC([](const VSEC & vsec)
diff --git a/src/uncore_pmu_discovery.h b/src/uncore_pmu_discovery.h
index 9d9f089d..7caddf7e 100644
--- a/src/uncore_pmu_discovery.h
+++ b/src/uncore_pmu_discovery.h
@@ -92,6 +92,9 @@ class UncorePMUDiscovery
             " globalCtrl: 0x" << std::hex << globalCtrlAddr;
             UncorePMUDiscovery::printHelper((accessTypeEnum)accessType, globalCtrlAddr);
             std::cout << " stride: " << std::dec <<  stride
+                      << " maxUnits: " << maxUnits
+                      << " statusOffset: " << statusOffset
+                      << " numStatus: " << numStatus
             << "\n";
         }
     };