PCI bottleneck?

I'm planning on buying a USB2.0 card because i've ran out of ports on the comp itself.

According to the guy at the store, (which is a small place, so I trust what he says, unlike those robots at pcworld) the card reaches some sort of bottleneck that is nowhere near the full 480mbps of USB2. What I need to know, is this a bottleneck in the PCI bus, or do on-mobo ports suffer from this limitation as well?

The card in question is a belkin 5-port USB2.0 card.

In fact will I even notice the difference for things like copying gigabytes of songs to my generic portable music player?

Thanks, any help and/or advice is appreciated.

The PCI bus is over 1Gbps, so that's unlikely.

If you had something like a RAID made of hard drives in USB enclosures I guess you could saturate the PCI bus, but one Flash [stick|camera|MP3 player] isn't going to come within an order of magnitude of filling the bus.

I don't know what the max throughput of the PCI bus is (PCI bus clock is spec'd at 33MHz), but USB 2.0 isn't going to be bottlenecked by the PCI bus.