I have several 3750X Cisco switches that, according to our Solarwinds NPM, are producing billions of transmit discards per day. I'm not sure why it's reporting these discards. Many of the ports on the 3750X's have 2960's connected to them and are hardcoded as trunk ports.

Solarwinds NPM version 10.3

Cisco IOS version 12.2(58)SE2

Total output drops: 29139431:

GigabitEthernet1/0/43 is up, line protocol is up (connected)
  Hardware is Gigabit Ethernet, address is XXXX (bia XXXX)
  Description: XXXX
  MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 100Mb/s, media type is 10/100/1000BaseTX
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:47, output 00:00:50, output hang never
  Last clearing of "show interface" counters 1w4d
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 29139431
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 35000 bits/sec, 56 packets/sec
     51376 packets input, 9967594 bytes, 0 no buffer
     Received 51376 broadcasts (51376 multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 51376 multicast, 0 pause input
     0 input packets with dribble condition detected
     115672302 packets output, 8673778028 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 pause output
     0 output buffer failures, 0 output buffers swapped out

sh controllers gigabitEthernet 1/0/43 utilization:

Receive Bandwidth Percentage Utilization : 0 Transmit Bandwidth Percentage Utilization : 0