[quotemsg=20743697,0,551379]"The constant high level of power running through the card, coupled with the taxing workload and heat, can damage the onboard circuitry and lead to the card failing far sooner than expected."
That's nonsense. A constant level of power is, if anything, beneficial as it avoids thermal cycling that induces physical stresses on delicate solder joints. And electronics, if properly cooled, can run for many years at full load.
Inadequate cooling could perhaps be a concern on cards used for mining, as could the wear on the fan bearings.[/quotemsg]
You're right about the thermal stress mostly however; there are other aging effects in semiconductors that are negatively effected by constant power. In particular, Electromigration is a huge problem in modern advanced semiconductors. Essentially, uni-directional electron flow causes stress to build-up due to momentum transfer from the electrons to the metal lattice in the chip interconnects. While companies try to design the wires in their chips to be "Electromigration-immortal" they usually have to allow some wires to be susceptible because they don't really expect their customers to have the chips running 24/7 at full load for years at a time. It should be noted that there is a relaxation effect that mitigates electromigration if you let the GPU rest for a while ( But this, as you eluded to, could have consequences as it could result in some mechanical stress). There are other aging effects too, e.g., Time Dependent Dielectric Breakdown, Hot Carrier Injection, and Bias Temperature Instability which can degrade the performance, cause faults in the data, or even permanent failure of the chip.