pgbouncer - massive overhead?

Given a baseline postgresql.conf config and a couple DL580 40 core/256GB memory I noticed a large over head for pgbouncer, has anyone seen this before?

$ pgbench -h `hostname -i` -j 32 -p 4320 -U asgprod -s 500 -c 32 -S -T 60 pgbench_500
Scale option ignored, using pgbench_branches table count = 500
starting vacuum...end.
transaction type: SELECT only
scaling factor: 500
query mode: simple
number of clients: 32
number of threads: 32
duration: 60 s
number of transactions actually processed: 1743073
tps = 29049.886666 (including connections establishing)
tps = 29050.308194 (excluding connections establishing)

$ pgbench -h `hostname -i` -j 32 -p 4310 -U asgprod -s 500 -c 32 -S -T 60 pgbench_500
Scale option ignored, using pgbench_branches table count = 500
starting vacuum...end.
transaction type: SELECT only
scaling factor: 500
query mode: simple
number of clients: 32
number of threads: 32
duration: 60 s
number of transactions actually processed: 8692204
tps = 144857.505107 (including connections establishing)
tps = 144880.181341 (excluding connections establishing)

processor : 39
vendor_id : GenuineIntel
cpu family : 6
model : 47
model name : Intel(R) Xeon(R) CPU E7- 4860 @ 2.27GHz

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