DELL Ultrasharp U2713HM supports HDMI but without build-in speakers!

I am stupid to buy such an expensive screen for my SONY VAIO Pro. When I connect VAIO to U2713 through, I was "stunned".

If the user connect his or her NB to DELL screen (not TV) with HDMI, do you think which sound driver will be changed to? The HDMI sound of course!

Fortunately, I know how to change the default sound drivers to "Realtek High Definition Audio", even connect to HDMI. But I wouldn't buy DELL products again.

SONY VAIO Pro 13 HDMI to VGA Screen is randomly twinkling

Recently, I bought a SONY VAIO Pro 13 Win8 NB.
It's nice in Win8 experience, elegant in the shape with very low weight.
However, I've tried it's HDMI output to screen with 1920x1080 resolution, the result is:

• HDMI out to screen HDMI port with HDMI line: it's work normally.
• HDMI out to screen VGA port with build-in HDMI-VGA adapter: the screen is randomly twinkling.

The result repeats while changing different screens or adapter lines. Also, I attempt to find updates and newest drivers from Windows and SONY, all updates were installed and patched, the problem still exists. Finally, I bought a new HDMI-VGA adapter (about 28 USD, support 1920x1080 resolution), the twinkling problem never happens. Obviously, SONY reduces it's cost in the HDMI-VGA adapter, even it may be worth about 10 USD cost only. But, I feel very uncomfortable on the brand (also complain it's Made in China quality) since all my smartphones and pads are SONY products.

Adapter on the top is about 28 USD, the bad-quality adapter on the bottom is included in SONY VAIO.