OkayRene
Member
http://www.overclock.net/t/1516121/gtx-970-comparison-strix-vs-msi-gaming-vs-gigabyte-g1
Asus
-Quietest, fans off below 60c
-Lowest internal clocks of all cards (hence lower TDP and heat)
MSI
-2nd quietest, fans off below 60c
-2nd best overclocker
-Better power phase design than the Asus
EVGA
-Overclocks the worst
-Similar noise profile to MSI
Gigabyte G1
-Has a backplate
-Overclocks the best
-Best power delivery circuitry
-Louder than the MSI, does not have a fans off mode
IMO MSI version is the best compromise. And BIOS flashing can get that locked internal clock to match the core clock speeds, i have mine from 1200Mhz to 1500Mhz on the L2 cache speed, and core at 1520Mhz, memory at 3900Mhz.
The different configurations are there because manufacturers want to differentiate themselves from others, and for different levels of performance. They'll have the blower type coolers as the cheaper end models, then the higher end models will have faster default clock speeds, larger and more effective coolers, and the flagship top end models might have prebuilt water cooling.
Thanks guys, this is super helpful.