What are the differences between the evga gtx 1070 ti ftw, ftw 2 and the black edition of these gpus?
Its largely the cooler and PCB. the GPU core in itself is largely the same.
The Black edition is your starting point, uses a basic 2 fan cooler and uses the Nvidia reference PCB. Also just comes with white LED lighting, no backplate and a single 8 pin.
The FTW 2 Edition uses a custom PCB (with a more robust power delivery system) a larger cooler which is wider and a bunch of sensors on areas like VRM's. The cooler also has RGB and does come with a backplate.
Not sure what the plain FTW is, do you have a link? I expect if will be however largely similar to the FTW2 in that the PCB is larger along with the cooler. There is a FTW Ultra Silent, which is an even bigger 1070Ti cooler being 3 slots thick., but PCB wise its the same as the FTW2, just a 3 slot rather then 2 slot cooler.
In all, the better PCB does not make a massive difference really with the 1070Ti and Pascal in general, The bigger cooler will allow the FTW models to run slightly quieter / cooler so may boost slightly higher all things being equal. In terms of actual clock speeds the cards will achieve outside of manual overclocking, it can be remarkably close with the way Boost 3.0 functions.
TL:DR, the FTW SKU's are better in most aspects, but it will not translate to a massive gain in performance, if the FTW model is a few $ more, then sure grab them, but do not overpay.
Thank you, looks like the ftw ultra silent is going for around 450-460 USD is this a good price for it?
For that sort of price, no not really to be honest. for less then 10% more then that price, you can get the RTX 2070 with reasonable aftermarket cooler that would put the 1070Ti in the ground: https://pcpartpicker.com/product/CGYLrH/gigabyte-geforce-rtx-2070-8gb-windforce-video-card-gv-n2070wf3-8gc with performance well over 10% higher.
Similarly, you can can spend $50 less and get a MSI Duke 1070Ti: https://pcpartpicker.com/product/Yfs8TW/msi-geforce-gtx-1070-ti-8gb-duke-video-card-gtx-1070-ti-duke-8g or Amp extreme 1070TI for $80 less: https://pcpartpicker.com/product/Nsbkcf/zotac-geforce-gtx-1070-ti-8gb-amp-extreme-video-card-zt-p10710b-10p
TL:DR I would not pay that much for a 1070Ti when for a small bump up in price the RTX 2070 can be had or spend much less for what are still a bunch of solid 1070Ti's.