OCZ's ZX Series 1250W currently is one of the most affordable 80Plus Gold PSUs with over 1200W capacity. This along with the fact that it performed very well in almost all our tests makes it a really good PSU for users who plan on powering three high-end graphics cards. It seems that OCZ made a strong come-back with the ZX series and the ZX 1250W can easily compete with the tough competition in the 1200 W+ Mega PSU category.

Although it did not manage to fully successfully pass the Advanced Transient Response Tests, the rail that failed (3.3V) belongs to the minor ones. In the meantime +12V, the most significant rail, showed outstanding performance. Efficiency in most tests, throughout 20-100% loads, was above 89% and even at full power was close to 88%. However at 50% load it didn't reach 90%, although I test with 230V and efficiency is 1-2% better compared to 115V.
Nevertheless, 80Plus certification conducts their testing at only 23°C ambient, while I run my tests at 45-50°C, so it's natural to measure less efficiency.

To sum up all above, if you need a powerful PSU to reliably feed a power hungry system with multiple graphics cards then the OCZ ZX 1250 is a great choice since it performs really well, is fully modular, has plenty of connectors and costs less compared to other >1200 W Gold PSUs. In addition it is covered with OCZ's five-year "power swap" warranty so in case anything happens you will be fine. Our only objection is that its transient filtering stage lacks an MOV, which filters spikes coming from the power grid (e.g. lightning). These spikes could easily damage not only the PSU but the rest of the components, too.