If you raise the discount rate by 1%, what happens to DCF value?

The value goes down. A higher discount rate means each future cash flow is worth less today, and cash flows further in the future lose more value because the discounting compounds over more years.

The size depends mostly on terminal value, which often makes up the majority of a DCF. With the Gordon Growth method and a 2% long-term growth rate, raising the discount rate from 10% to 11% changes the denominator from 8% to 9%. Terminal value as a multiple of next year's cash flow drops from 12.5 to about 11.1, roughly 11% lower, and then that smaller number is discounted at a higher rate too. Adding the smaller hit on the projected cash flows, a typical company might lose somewhere around 10% to 15% of its value, more if growth is high and the spread between discount rate and growth is narrow.

If terminal value comes from an exit multiple, the terminal value itself does not change; only the present value factor falls, so the decline is smaller. Over five years, discounting at 11% instead of 10% lowers the present value of terminal value by roughly 4%. That is why I always show a sensitivity table across discount rates and growth rates or multiples.