= Testing four different USB3 PCIe cards =
 * 1x PCIe interface
 * Two different computers (sigh)
  * 2GB 1867 MHz Intel Core 2 7466.96 BogoMIPS Intel DPP3510J 03/06/2008, 2TB USB3 Seagate, Plugable
  * 4GB 2000 MHz Intel Core 2 8790.70 BogoMIPS Intel MQ96510J 12/27/2006, 3TB USB3 Seagate, other cards
   * this may not be a fair test of the older card, but it isn't available any more, so ...

 * Scientific Linux 6.1, 2.6.32-121.21.1.el6 kernel, ext3 file systems, runlevel N 3

 * 10 GiB file (10737418240 bytes), multiple overwrites with
  * date ; dd if=/dev/zero of=/backup/testfile bs=1M count=10240 ; date
  * repeated three or more times, writing the file initially was slower

|| card                        || source ||    date || price ||     Chipset || Ext || Int || Time || Rate ||
|| Plugable  PCIE-USB3-SP      || Amazon || 2012/04 || 25.95 || Ren D720200 ||   2 ||   0 || 265  || 45.6 ||
|| BYTECC  BT-PEU310           || Frys   || 2012/04 || 26.98 || Ren D720200 ||   2 ||   0 ||<-2> NFG      ||
|| Vantec  UGT-PC345           || Newegg || 2014/04 || 22.99 || Ren D720201 ||   2 || "2" || 120  || 89.8 ||
|| Siig  BBGS407X JU-P40212-S1 || Newegg || 2014/04 || 29.99 || TI TUSB7340 ||   3 ||   1 ||  44  ||  244 || The Best ||

Plugables no longer sells PCIe cards.

Vantec uses funny 20 pin internal connector for the other two USB3 connectors.  Newegg sells a $7 adapter cable and connects to some Asian sources for $4 or more.  So, call it a two port card, if you want four ports go with the Siig.

The xhci drivers for USB3.0 did not appear in the Linux kernel until 2.6.31, and are still improving through the 3.x series.