If yes then, solo mine or pool?
If you're mining to help the network (and that's really the only reason with a bad computer) and you can, solo mine.
You may want to look into underclocking/undervolting to make the efficiency slightly less bad, unless you 100% don't care about electricity/heat.
To support the network we have recently started mining on our Monero payment processing droplet at digital ocean.
[2015-10-30 02:57:21] thread 2: 177 hashes, 8.38 H/s
[2015-10-30 02:57:21] thread 0: 170 hashes, 8.03 H/s
[2015-10-30 02:57:21] thread 1: 174 hashes, 8.24 H/s
[2015-10-30 02:57:21] thread 3: 175 hashes, 8.25 H/s
[2015-10-30 02:57:39] thread 0: 121 hashes, 6.81 H/s
[2015-10-30 02:57:39] accepted: 178/178 (100.00%), 31.68 H/s at diff 16000 (yay!
!!)