Quad core vs Dual core, and Inel graphics

Hi all,

I’m trying to decide between a 2012 quad core 2.3GHz i7 and a 2014 dual core 2.6GHz i5. Yes, I wish they had a 2014 quad core Haswell with upgradeable RAM and a second HD bay like the 2012, plus a faster clock speed and Iris Pro graphics, but they don’t.

The main differences I see are listed below. I didn’t list the soldered on RAM in the 2014 because I’d be ordering it maxed out with 16GB of RAM. The same with the 2012; I’d be buying and installing 16GB of RAM. So in that respect, they’re even. And price comes out about the same, $900.

2012 Quad 2.3 i7 vs 2014 Dual 2.6 i5

I’m decided on 3-4-5. My main questions deal with cores and graphics.

Question 1 is about cores. I’ve read from some people on other sites that for my low level use (email, MS Office, browsing, Youtube) I won’t even be accessing the extra cores on the quad, and that the unmaxed dual cores with a faster clock speed and Haswell CPU should actually work faster in my situation. So that’s my question. Is that true? And is that likely to hold true in the future with the trend in apps related to my usage (the quad core should still be “unnecessary” in the next 5 years or so, given my usage)?

Question 2 is about the graphics. I’ve read wildly different estimates as to how much faster Iris is than the 4000 (anywhere from about 10% to 90%). Anyone know how much difference I’m likely to see between the two, given my usage? And is that likely to hold true in the future with the trend in apps related to my usage (higher graphics intensive apps playing that much better on Iris compared to 4000, again, given my usage)?

I’m trying to buy for now, but I tend to keep my Macs for 6-7 years, so I’m also trying to look at the future.

Any benchmarks, facts or educated opinions are welcome.

Thanks!