Do new or older cards return better profits?

I’m new to the whole mining scene, but I have a pretty high-end gaming rig that sits idle most of the time.

I started playing around with it for mining on different currencies and eventually, that led me to zcash. In my current machine I have 1 Nvidia 1080 Ti 11GB. That card mines a little over 700 H/s and with watts usage and the low electricity price in my area it would yield me a profit of about 100/month at zcash’s current prices.

I can add up to 3 PCI Express cards to this rig; if I put in another 2 1080 Ti cards that match my existing card that is about $1600 investment, but if zcash stays at today’s prices (or goes up) I should make that back in about 6 to 8 months.

Now if I look at a card like the GTX960 4GB; those can be had for around $200 so $400 for both cards; 1/2 the price of one new 1080 Ti. What I’m not sure is how the hash rate and watt usage is on these older cards to understand what is the better investment?

clicking the search spy glass in the top right corner and typing in 960 I get these two posts and many others

Maxwell cards are way lower efficiency and most of them go crazy with temps if you try to push them a bit. Stay away from 9xx series unless you have some already laying around.

I would say stick with your 960 till you can get the 1080 TI (not over clocked) I find from a numbers perspective they are the better bet.
Just my opinion.