First limit your fps as recommended above.
Second watch your vram junction temp. 3090 tends to overheat its vram especially on the backside. This also affects watercooled cards because only the front side is well cooled, the backside is inadequate cooled by almost simply an backplate. I put an vintage 3,5“ hdd cooler on the back of my card and get about 20 degrees lower temps.
With that and an conservative UV/OC to 0,875mV/1875Mhz I am almost out of ctd‘s now. But have still some strange hardcrashes with freezes/reboot once a week.