Thats to broad of a question. Each 5700 is different and can handle more or less OC/UV. So what brand and model do you have?
Question to you would be are these stock 5700 or 5700xt?
Have you flashed the xt bios onto a 5700 if it is base model?
Have you modded the bios (copied 1500 straps on down)?
None modded 5700 is usually good at 1175 core, 750 v, 1800 memory, 850 v
modded 5700xt is usually good at 1300 core, 775 v, 1800-1820memory, 850 v
That will give you a starting point, u can make adjustments based on if you card can handle those settings without crashing or a bunch of stale shares.