While teaching an OptiView XG course not long ago, an attendee asked a question about the "small" capture buffer available on the product. He wanted to know when it would go from 4GB to 8GB, 16, 32, or beyond.
The reasoning behind the question was that in a high-throughput environment like a data center, 4GB can fill up pretty quickly. Which, is true. If the XG is connected to a 1Gbps link that is 50% full, a 4GB buffer with no filtering will get just over a minute's worth of capture time.
Have you ever opened a 4GB trace file in a packet analyzer? Wireshark, ClearSight or otherwise?