I have tried 2 cards. A 6 port card with an nvidia chip, and a 5 port NEC card
both worked well once I discarded a faulty usb cable to a hub I was using.
The NVidia chipped card is the MP5273 (6)
http://www.chronos.com.tw/_products_061 ... 5273-6.htm
PCI 6 PORT USB 2.0 CARD
Features:
USB Interface
One EHCI USB 2.0 and three OHCI USB 1.1 Host Controllers for supporting up to six USB Ports.
Supports HS (480Mbits/sec), FS (12Mbits/sec) and LS (1.5Mbits/sec) data transfer rate.
PCI Interface
Compliant with PCI specification 2.2.
Supports up to 33 MHz PCI interface clock.
Supports PCI bus power management specification 1.1.
High performance PCI bus master.
2.5 V core, 3.3 V I/O, 5V tolerant input.
128-pin PQFP Package.
The 5 port PCI card P/N: MM-U2NEC101-4E1I
http://www.aliexpress.com/store/900661/ ... ipset.html
I have had a printer, camera, and one or other of 4 usb2 hubs connected and all work fine on two A1 XEs
Writing up to 3GB in one hit, no lockups or crashes - no numbers sorry.
Impressions: Writing 3GB still seems to drag along, lets agitate for USB3

Copying from the card is very much faster, smaller files read or write in a flash.
For the record the hubs tested with and without power are
I-rocks 4 port hub and card reader
I-rocks 3port hub
DSE 7 port hub
Aten 4 port magnetic hub (unpowered only)
SSK SB reader
1 GB, 4GB SB cards; 2GB, 4GB, 8GB flash drives.
Noel