Performance issues

[Yuriy Mitrofanov]

I have a very simple code to test performance:

boost::asio::thread_pool testPool(std::thread::hardware_concurrency());
std::atomic<uint64_t> nDataCount{0};

for (const auto& id : objectIDs) {
  boost::asio::post(testPool, [id, &nDataCount]() {
  std::vector<unsigned char> vData;
  if (g_db->ReadObjectSegment(id, vData)) {
  nDataCount.fetch_add(vData.size());
  }
  });
}

testPool.join();

On ASUS PRIME Z390-A
Intel® Core™ i9-9900K × 16
64.0 GiB
I get this result:
DB objects read: 44.74 GB
DB objects read count: 23056081
DB objects read time cpu: 15 s 373 ms
DB objects read time one: 666 ns/op
DB objects read speed: 2.91 GB/s
DB objects read OPS: 1499709 op/s

At the same time, all cores are loaded almost 100%


On HP ProLiant DL380 Gen9
Intel® Xeon® E5-2697 v4 × 72
512.0 GiB
I get this result:
DB objects read: 44.74 GB
DB objects read count: 23056081
DB objects read time cpu: 2 m 9 s
DB objects read time one: 5630 ns/op
DB objects read speed: 352.93 MB/s
DB objects read OPS: 177618 op/s

At the same time, all cores are loaded almost 5-10%

Can anyone tell me what is the reason?