DisplayPort to Dual Link DVI adapter

[encryptededdy]

I really needed one of these to drive my (DL DVI only) 2560x1440 monitor from my (HDMI & DP only) laptop, but I was very annoyed that basically all cost $80-100 USD. Finally bit the bullet and bought one, then took it apart to see what made it cost so much. Surprised to find so much inside.

This particular adapter is Dell branded but made by BizLink.

Input: DisplayPort and USB, Output: DL DVI. The entire thing is in a (presumably) magnesium case.



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The two Silicon Image Sil7172s are iTMDS Transmitters. I assume two are required for the Dual Link functionality.

The STM GM68020H is a DisplayPort receiver IC

[tooki]

Why are you surprised? The reason single-link DVI adapters are cheap is that DisplayPort has a DVI/HDMI compatibility mode, where the DP transmitter outputs DVI/HDMI signaling, so only a cheap passive adapter is needed. But DP doesn't have enough pins for dual-link DVI, so those adapters need a DP receiver and two DVI transmitters, and whatever logic is needed to convert the actual video format.

[encryptededdy]

Why are you surprised? The reason single-link DVI adapters are cheap is that DisplayPort has a DVI/HDMI compatibility mode, where the DP transmitter outputs DVI/HDMI signaling, so only a cheap passive adapter is needed. But DP doesn't have enough pins for dual-link DVI, so those adapters need a DP receiver and two DVI transmitters, and whatever logic is needed to convert the actual video format.

My logic was more that you could get Active DisplayPort -> SL DVI or -> HDMI adapters for ~20 USD (active generally for use with AMD Eyefinity). However these only use one chip.



I would've assumed that a DL adapter would also be a simple design, perhaps with just one extra chip or something.

[Kilrah]

If you look at the product sheet for that single component it's indeed nothing but a signal buffer/conditioner, there's no actual processing happening like needed to split a stream into 2.

[wraper]

My logic was more that you could get Active DisplayPort -> SL DVI or -> HDMI adapters for ~20 USD (active generally for use with AMD Eyefinity). However these only use one chip.
I would've assumed that a DL adapter would also be a simple design, perhaps with just one extra chip or something.

That one chip is just level shifter, nothing more.