Computer Graphics vs Bio Engineering

So I'm a first year CS PhD student at a top school (say one of MIT / CMU / Stanford / Berkeley); and I'm not sure whether to go with computer graphics or comp. bio.

Problems I have are as follows:

Con:

computer graphics: what are the big problems left to solve? recent looks at siggraph shows lots of me-too work; doesn't seem to have an abundance of funding either; really cool in that i can largely work alone; that all I need is a laptop; and that in the worst case, I won't accidently do anything that results in health damage to self / ppl around me

bioengineering: not bioinformatics; amazing things going on, with metabolic engineering, people building a cell from scratch; plenty of funding. on the other hand, impossible to do anything without lots of funding, bad experiments / accidents may result in health damage (also in buildings where other ppl's bad experiments may result in health damage to me); but very high impact work if pulled off successfully

have others here debated this? "computer science vs bioengienering" for research; if so, what conclusion?

thanks!