crwlngsnk, thanks for your input! At this point, I'm not super concerned about numbers, just a gut check that I'm on a path that helps me get to my goal. I'm hoping to generate enough interest that I will
get dissenting views on hardware choices. And, please, let's minimize the shaking of any lemurs... they have enough trouble as it is
Ultimately, I can only build one machine, but I'm curious about the different approaches that folks would take to get there.
As far as the GPUs I'd have to say that three high end, but not very tippy-top high end will out produce two of the very tippy-top ones. I'm not sure what the Folding difference is between say a 780 and a Titan is, but I'd be hard pressed to believe that the Titan can do 1.5 times the work of the 780.
This is pretty much where my gut is, too. I'm guessing that diminishing marginal returns will kick in pretty substantially when comparing the two top cards in a line up, especially when looking at PPD/$. But, I'm curious if this is in fact the case.
Some of the decision will depend on heat, noise, power consumption, etc
...I'm consigned to the fact that I'll be drawing a significant amount of electricity, generating a bit of heat, and have a dozen or so fans spinning to keep the new build running. Our place is 101 years old, so the windows are more akin to pasta strainers than actual physical barriers to air movement. So I'm already used to higher than preferred utility bills... our A/C bill can already get pretty high during the summer, and don't even get me started on our heating bill this past winter
So, as long as we can keep it reasonable on the electric bill, I'm cool with that, and during the winter, the addition where I have my office is not insulated very well, so the extra heat will be much appreciated.
I guess my biggest concern, given my ambivalence to heat and power consumption, is noise. I know that I won't have a silent machine, but I'd prefer to keep noise down where I can.
Also wondering... I'm thinking about the OS, and while I can get Windows 8 for < $10 (have to pay full price for Win 7, my preferred OS), I was also rolling around the idea of taking this opportunity to learn a bit of linux, but I don't know anything about the learning curve around this, and am wondering how much of an impact that will have on my folding.
Thanks again for your help!