If you are asking if it will be GPU mine-able, I highly doubt it. While I am sure it will only get a fraction of BTC's hashrate, you need to remember that mining BTC has been ASIC only since early 2013.
The best case scenario, would be some
early Bitcoin ASIC hardware might be useful again for a month or two. However, there are many people who support Bitcoin Cash who do have modern hardware and who will be switching some portion (or all) of it over.
I decided to look into this bit more after I posted the above. With the new information, I think only mining hardware acquired within the last year would even be viable on the BCC network, so disregard even the early ASIC equipment comment I made earlier.
Here is a link I found that shows some of the historical Bitcoin difficulty numbers:
https://docs.google.com/spreadsheets/d/1DQYQOLsB-pJWGu5e8CXF4vkxdYHEJDOyxQptBmC_030/edit#gid=0I remember moving away from GPU of mining of BTC and moving to alts such as LTC during early 2013, so let's look at the difficulty at the beginning of that year as an example.
The January 8th, 2013 difficulty shows as: 3,249,550
The latest difficulty is: 860,221,984,436 (
https://bitcoinwisdom.com/bitcoin/difficulty).
This represents over a 250,000x increase in difficulty over that time span. Also the block reward back then was 50 BTC/block versus only 12.5 BTC/block today.
Anyway, even if BCC gets 1/10th of BTC's current hash-rate, the BCC mining difficulty might eventually drop down to ~86 Billion. In other words, this would mean a GPU will have a roughly 25,000 as hard of a time to find a block as it did in early 2013.