Catalyzes the NAD(P)H-dependent reduction of dihydroxyacetonephosphate (DHAP or glycerone phosphate) to glycerol 1-phosphate (G1P). The G1P thus generated is used as the glycerophosphate backbone of phospholipids in the cellular membranes of Archaea. Is also able to catalyze the reverse reaction, i.e. the NAD(+)-dependent oxidation of G1P but not of G3P. Is not active toward glycerol, dihydroxyacetone, glyceraldehyde phosphate, and glycerol-2-phosphate. NAD(+) + sn-glycerol 1-phosphate = dihydroxyacetone phosphate + H(+) + NADH NADP(+) + sn-glycerol 1-phosphate = dihydroxyacetone phosphate + H(+) + NADPH Binds 1 zinc ion per subunit. Totally inhibited by EDTA in vitro. Optimum temperature is 94-96 degrees Celsius. Over 96 degrees Celsius, the activity decreases dramatically. Hyperthermostable. The half-life of activity is 30 minutes at 95 degrees Celsius and increases to 2 hours at 90 degrees Celsius. Membrane lipid metabolism; glycerophospholipid metabolism. Homodimer. Catalysis proceeds by an orered bi-bi kinetic mechanism. Belongs to the glycerol-1-phosphate dehydrogenase family.