OCC has published a review on the Ultra X4 1050W Power Supply
On the whole the Ultra X4 1050W performed very well. The DC voltage load regulation was very good with little fluctuation from zero to full load. The noise/ripple levels although within the limits set down by the ATX12V V2.2 specification were a little higher than I would like especially on the 12V rail. The Ultra X4 1050W marginally failed to maintain the minimum level of efficiency of 80% as required by its 80 Plus certification giving 79% at 20% loading on 110VAC. The power factor dipped below 0.9 which is very unusual even on some mid range power supplies.Ultra X4 1050W Power Supply Review
