lph

The 1080 Ti would have lower clock speeds because it has far more CUDA cores.
 
If the upgrade is free, don't question it and go for it. I would deal with a turbo blower cooler if it meant getting 1080 Ti. The tolerance of noise is up to you though.

We're happy to help, that's what we're here for, enjoy that awesome and free performance upgrade!? Sheesh, I wonder if my GTX1080 were to 'accidentally' die on me, would they gimme such an upgrade??

so free upgrade? hell yah

Why would you even question this. The price difference between cards is huge and so is the performance 

1080ti without a doubt. Not sure id get that vairient. Bottom of the barrel but maybe if it was free. 

Regardless it’s way better than a mid range 1070ti. 

this doesn't matter in a video card. unless you match 2 of the same types together. like an evga gtx 1070 sc vs evga gtx 1070 sc for example. 

When comparing your gtx 1070ti towards something newer you always need to check the differences at least nvidia wise in the cores. cuda cores rt cores etc etc etc. 

More = better. and the gtx 1080 ti has a lot more. it was the gaming king. well.. till the rtx 2080ti released and blew the 1080ti out of the water as if it was nothing  

But that will probably happen with the newest "80 ti" when that releases. next year or so.

I mean if it's a free upgrade.... yeah... it's around 35% faster than 1070ti.

1080 to 1070ti not that much of an upgrade but 1080ti is a huge step over 1070ti, so go for it.

The only downside is that the 1080ti they are offering you has a blower cooler. Otherwise it's simply just better in every way (exept power consumption).

It has over 50% more CUDA cores.... I'd change, 100% of the time.

There is a fair bit of performance improvement going from GTX1070 Ti (similar in performance to GTX1080) to a GTX1080 Ti (additional 3GB of VRAM to boot). So, if they're offering this upgrade, why not? BTW, how much do you need to top up?