A comparison between the performance of traditional optical code-division multiple-access correlation receivers and that of recently proposed chip-level receivers is presented. The performance is measured in terms of both throughput and efficiency capacities. Signature code correlations bounded by either one or two is employed. The bit error probabilities for chip-level receivers, with code correlations bounded by two, are derived. That with code correlations bounded by one is recited from previous literature. Our results reveal that chip-level systems are much more efficient and their throughput capacities are much higher than that of traditional correlation systems. Further, the throughput capacity of chip-level systems can be increased by almost a factor of 3.4 when increasing the code-correlation constraint from one to two.