Test Setup:

CPU : Intel I5 750 Retail
Motherboard : ECS H57H-MUS
RAM : G.Skill Ripjaws F3-12800CL8D-4GBRM
Video : ATI RADEON 4890 1GB OEM
Power Supply : Cooler Master UCP 700W
HDD : Seagate Barracuda 320GB 7200.10

Here is how the fully assembled testbench did look like:

The Intelligent Power Saving (IPS_LED) feature is represented by a row of different color LEDs, that show the level of load:

-Green 1 and 2 -> Light Load
-Yellow 1 and 2 -> Normal Load
-Red 1 and 2 -> Full Load

In the 4GHz tests I've done, the red LEDs stayed lit up most of the times, so the energy saved was very little:

I could clock the CPU at 4GHz without stability problems. Here is the CPU-Z at that speed:

Also, here is the CPU-Z validation:

To test the system stability, before the benchmarks I have ran LinX and encountered no errors at all:

After obtaining a fully stable 4GHz clock speed, I have taken some BIOS shots, for people to see around which voltage, memory timings and host clock values this speed could be obtained:

Here is some more detailed motherboard information, with the help of the Everest Ultimate utility:

To test the USB 3.0 expansion card, I have used a Western Digital Scorpio WD3200BEKT 320GB 7200RPM HDD and the Brando USB 3.0 2.5'' SATA HDD Enclosure. Here are the results I have obtained, compared with the previously tested ASUS card: