Here's a the benchmark results of my early and late 2015 iMac 27'' 5k's if anyone is interested.
Both have the built to order 4Ghz i7, 32GB RAM, 512GB SSD and the top graphics card (M295x,M395x) respectively.
Note that on my late 2015 iMac, I'm using slightly faster / lower latency CAS 10 memory: http://www.crucial.com/usa/en/bls2k8g3n18aes4
The late 2015 iMac's screen has noticeably more vivid colours - almost too vivid late at night, bright florescent colours can be overwhelming in a dark room.
The M395X is 'acceptable' and allows you to play any game but certainly not past medium settings on modern games, for example Elite Dangerous needs to run at 2880x with most settings on medium / medium high at most.
The NVMe SSD is the biggest advancement IMO, it's very noticeably faster and leaves my early 2015 iMac feeling sluggish on IO intensive tasks.
For the detail comparison see: http://browser.primatelabs.com/geekbench3/compare/3958302?baseline=3958474
Both have the built to order 4Ghz i7, 32GB RAM, 512GB SSD and the top graphics card (M295x,M395x) respectively.
Note that on my late 2015 iMac, I'm using slightly faster / lower latency CAS 10 memory: http://www.crucial.com/usa/en/bls2k8g3n18aes4
The late 2015 iMac's screen has noticeably more vivid colours - almost too vivid late at night, bright florescent colours can be overwhelming in a dark room.
The M395X is 'acceptable' and allows you to play any game but certainly not past medium settings on modern games, for example Elite Dangerous needs to run at 2880x with most settings on medium / medium high at most.
The NVMe SSD is the biggest advancement IMO, it's very noticeably faster and leaves my early 2015 iMac feeling sluggish on IO intensive tasks.
For the detail comparison see: http://browser.primatelabs.com/geekbench3/compare/3958302?baseline=3958474