Does your switch even supports team/bonding/etherchannel/lacp etc?
By the way, ang common misconception about teaming is, mado-double ang speed, ie 2 Gb NICs == 2Gbps. Not really. It only means na kung may 2 o mahigit kang processes, they can utilize 1Gbps (at most) separately. But never a single process can utilise the "bundled" speed of 2Gbps.
Bumagal kasi nga hindi:
- properly bonded sa client
- switch does not support bonding
Either way, it results to loss packets loss and only gets re-transmitted.when they timed out.