I'm wondering if there high performance USB controllers in the same way that there are high performance NIC cards. I'd like a way to run a USB device with minimal load on the main CPU.
I've not come across any - if high throughput with less CPU load is required, most device manufacturers have traditionally opted for IEEE1394/Firewire/i-link although the range of new interlink types coming out recently (eg: Thunderbolt (formerly Light Peak) etc.) is mind boggling
I've seen reports that USB performance can be affected by controller chip, but I haven't seen any info on CPU load.
I'll try to dig up some sources now.
For start, there's this review.
There are also interesting pages which comment of maximum sustained speed of USB controllers. FOr example, take a look at these controllers and speeds on this page. PLX Tech controllers support up to 40 MB/s speeds, while some controllers mentioned at beyondlogic have maximum sustained speed of 12 MB/s.