Hello, tha Vram issue is anyoing.. yes it will help, every 1 GB of ram is aprox 45 Mil triangles, without texture...... But realisticaly, going over 100 Mil will be problematic even then ( its something that was unthinkable few years back )
So teoreticaly, without texture, it should be possible to open and work with 200 Mil mesh ( with some reserve 250 Mil )
Im working with 7970 3 GB VRAM, an its get problem to go over 100 Mil ( propably a driver issue, it seems that it could not get properly in VRAM ) Im set decimation to 50 Mil, and its quick in viewport
How much VRAM you have now ?
Can report us then how it work with TITAN ? :-)