mg := &MetricsGroupV2{
		cacheInterval:    10 * time.Second,
		metricsGroupOpts: opts,
	}
	mg.RegisterRead(func(_ context.Context) (metrics []MetricV2) {
		lastSyncTime := atomic.LoadUint64(&globalIAMSys.LastRefreshTimeUnixNano)
		var sinceLastSyncMillis uint64
		if lastSyncTime != 0 {
			sinceLastSyncMillis = (uint64(time.Now().UnixNano()) - lastSyncTime) / uint64(time.Millisecond)
		}

	objectAPI, _ := validateAdminReq(ctx, w, r, policy.BandwidthMonitorAction)
	if objectAPI == nil {
		return
	}

	enc := json.NewEncoder(w)
	if err := enc.Encode(madmin.ClientPerfExtraTime{TimeSpent: atomic.LoadInt64(&globalLastClientPerfExtraTime)}); err != nil {
		return
	}
}

// ClientDevNull - everything goes to io.Discard
// [POST] /minio/admin/v3/speedtest/client/devnull