USB 3.0 Speed in an ESXi 5 virtual machine can be decent

The graphs below hopefully speaks for themselves, but just in case...

Here's what HighPoint's site says about the RocketU 1144A 4 port USB 3.0 PCI-E card:
The Industry's First PCI-E 2.0 x4 USB 3.0 HBA: Class-Leading 20Gb/s Transfer Bandwidth

My goal was to have fast and stable transfer speeds to an external RAID array, using 4 x 1TB 7200 rpm drives in this Mediasonic HFR2-SU3S2 enclosure, avoiding sometimes problematic eSATA (hot eject, etc). I also need to have multiple USB ports, for UPS, TED, etc.,without resorting to hubs, or the possibility that those other devices would slow the USB 3.0 connection to the RAID, the way many USB 3.0 "hubs on a card" could. This works because the quad card actually has 4 separate ASMedia USB 3.0 controllers. While I don't have the patience or time to test concurrent loads, it appears that I can already tentatively conclude:

• the ~$30 2 port USB 3.0 card is slowed about 25% when running inside an ESXi 5.0 VM with passthrough enabled
• the ~$90 4 port USB 3.0 card is slowed about 04% when running inside an ESXi 5.0 VM with passthrough enabled
• the ~$90 4 port USB 3.0 card is nearly 2x as fast as the 2 port USB 3.0 card for writes, so it's a keeper
• I've done enough testing/graphing, I'm now ready to continue to finish my build, now that I'm confident my USB 3.0 transfers are stable and fast
• I didn't have this confidence a year ago, see my experiments here, where the NEC chipset required a firmware update

Really nice article, with all the techie details at anandtech here:
HighPoint's RocketU 1144A PCIe x4 USB 3.0 Controller: A Big Back-end

And all the details about how to set up passthrough over here:
TinkerTry.com/usb3passthru.

I should also mention that subsequent runs using ATTO Disk Benchmark 2.47 gave very nearly identical results, with results varying less than 2%.

Nov 21 2011 Update: see also even faster results using the ASRock XFastUSB utility, at TinkerTry.com/xfastusb