ATI Radeon HD 5770 and 3 monitors : 2x mini DisplayPort to HDMI, 1x DVI-D to DVI-D

These AMD-specified ACTIVE Single-Link DVI adapter/converters (like those Accell ones) are about US$30 because they have driver electronics in them.

Simpler, cheaper adapters just have two connectors and some cross-wiring, no circuitry. But when you need to drive three displays, the graphics card runs low on power, the signal levels get too low, and your displays drop out. That's why you need ACTIVE.

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"5770 only supports two ports at once.You will need a second video card to support more than two screens."

This statement is incorrect.

Guys,

I have late 2009 MP and two monitors with both DVI & display port (NEC PA301W & NEC PA271W) and they where working fine.

I need a third one and was trying to connect an old 20" HP LP2065 (2xDVI 1600x1200) but no success. It was connected to DVI port.

System is kind of detect it (I can see 3 monitors in display settings) and unit stay active (signal is going through the cable) but screen is black.

According to Apple note this config should be perfectly supported:

http://support.apple.com/kb/HT4279

HP unit is fine since it works fine on my MBP.

Eventually I connected it with installation of second old stock NVIDIA card but don't like this setup.

Is anybody have some suggestions?

Thanks

To clarify:

Both NEC displays has ability to be connected either through DVI or display port.

Actual not properly working config:

2 x NEC connected directly through display port to 5770.

HP connected directly through DVI to 5770.

All passive connections.

Actual working config:

2 x NEC connected directly through display port to 5770.

HP connected directly through DVI (or display port to DVI Apple adapter) to stock NVIDIA card.

All passive connections.

Thanks

Hi, this is my first post here. I've read all posts from Apple, AMD and the web in general and now I'm all confused. I have a Mac Pro 2010 with 5770 (2 miniDP, 1 DVI). I bought 2 NEC E231W (single link) that have both DVI and display port. I want to connect these two displays AND my HDMI TV with the sound.

To connect the TV, I have a miniDP -> HDMI (active or not, I don't know) that works with the sound. This leaves me 1 miniDP on the graphic card and the DVI. I have connected 1 NEC directly with miniDP -> DP and the other NEC with DVI -> DVI.

Problem, only two displays work at the same time. When I connect the third one (DVI or DP or HDMI), it simply turns off an already connected DP.

So now I really don't understand anything.

The following page : http://www.amd.com/us/products/technologies/amd-eyefinity-technology/how-to/Page s/faqs.aspx#three-monitors says:

In contrast, active adapters will actively translate the DVI signal coming from the monitor into a native DisplayPort signal for the GPU (and vice versa). A native DisplayPort signal is required for AMD Eyefinity because DisplayPort signals can be synchronized by the GPU to keep all of your monitors moving in concert.

This DisplayPort signal can also be synchronized with DVI and HDMI signals, but only two of these signals may be utilized on an AMD Radeon™ GPU. This is why AMD Eyefinity technology requires a native DisplayPort signal for the third (or higher) monitor.

Since I have two non DP signals (DVI and miniDP-> HDMI) but a third one which is native, what's wrong ?

The following page http://store.apple.com/us/question/answers/readonly/to-use-three-monitors-does-th is-work-with-the-recentlyavailable-active-singlelink-dp-to-dvi-adapters-not-the- simple-passive-one-that-apple-sells/Q2DXTYFJUCTKUU2YH says :

To run 3 monitors with this card - 2 of them need to be "active" on the display port connections.

Why is that ? It's not the same as the official AMD documentation.

(Of course, I have also read this http://www.overclock.net/t/721931/active-vs-passive-displayport-adapters-the-tru th)

To get DVI (or closely compatible HDMI) out of a DisplayPort or Mini DisplayPort, you assert a signal that sends the port into "Dual mode", and it then produces signals and timing compatible with DVI (or with the signals shuffled, HDMI). The compromise signal levels produced may not be compatible with all DVI or HDMI devices. An ACTIVE adapter will boost the signals up. ACTIVE adapters contain signal boosting chips, and are therefore more expensive than passive. If you had an ACTIVE adapter, it would have been sold as ACTIVE.

There is one small power pin available in the Interface, and it can supply power to run signal booster for up to 1080p or DVI up to 1920, but cannot power the larger chip need to convert to Dual-Link DVI. That one requires the Dual-Link adapters with a USB pigtail for additional power.

The guy who posted "the Truth" on overclock.net does not have it right. He needs to go back and re-read some AMD eyefinity documentation, and study the DisplayPort article from wikipedia.

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I do not know why your particular graphics cards seems to be falling short of the specifications. It may be defective in some small way.

If it were mine, I would buy an ACTIVE adapter to see if the situation resolved itself, since the symptoms so closely resemble the symptoms you get with too many passive adapters in use.

Hi, thank you a lot for this quick answer. I'll tear appart (again) my miniDP->HDMI to see what's inside, maybe it'll give us as hint to know of it is active or passive.

Here it is.

According to the constructor :

http://www.lontiumsemi.com/english/Product1.asp?BigClassID=1#findNode1

LT8611EX：LT8611EX integrates 1-to-1 DP Repeater & DP to HDMI/DVI Level Shifter to simplify system level design and reduce system level cost. It can be used as either a DP signal to HDMI level shifter, or as a DP signal repeater extending the reach of the Display source. LT8611EX can also be used as a HDMI signal repeater.

=> It doesn't seem to be very 'active' in the way I'd like it to be. Apparently it just does levels conversion.

what a wonderful photoshopping ! 😀

Grant,

I have spent many weeks researching this topic online, and despite the vast plethora of forums on this, it almost seems like NO ONE knows how it works.
You are by far the most knowledgable person on this subject that I have been able to find. Ok, I'm done sucking up.

I have an ATI Radeon 5770 that was apparently a flashed PC model. In device profiler it shows up as the 5770, and also has this line -

"EFI Driver Version: 01.00.436"

Anyway, it has two DVI ports, one DP, and one HDMI.

Currently, I am running a DVI>DVI and DVI>DVI-VGA Adaptor to drive two displays. I want three damnit 🙂

I purchased what I thought was an active DP-DVI adaptor today, but I was apparently mistaken.

http://www.bestbuy.com/site/rocketfish-displayport-to-dvi-d-adapter/8927855.p?id =1218955993012

My question is this-

• Is one active DP-DVI/HDMI/VGA adaptor, with two passive DVI connections enough for a 3 display setup?
• It can't be a deal killer only having one Display Port, can it?

I just bought the card off of eBay and the seller was most profuse about the card being able to drive three displays. I haven't rated the seller yet 😉

Thank you for your time!

Currently, I am running a DVI>DVI and DVI>DVI-VGA Adaptor to drive two displays. I want three

DVI to DVI is just wires. If your display is wider than 1920 wide, you need Dual-Link cables, which means it has the data lines doubled. The entire grid MUST be populated with pins for it to be Dual-Link, but the reverse is not definitive -- (some are populated but not connected).

DVI-I on a computer also present a VGA interface directly on the blade at the end of the connector and the four pins around it. So this "adapter" is just a re-wire, NOT a converter.

Some of these cards may have Dual-Link DVI on one port, and Single-Link DVI on the other port, and no identifying information on the card.

The RocketFish Adapter wins the prize as the most disappointing adapter, ever. It does not seem to work for most Mac Users.

ACTIVE Adapters to Single-Link DVI contain electronics and cost more so they always say they are ACTIVE in their Ads. Accell and StarTech make good ACTIVE adapters for about US$30. Check carefully for DisplayPort Vs. Mini DisplayPort so you get the connector you need.

If you need to go wider than 1920 wide, you need an ACTIVE Dual-Link adapter with a USB pigtail for even more power. The Apple version costs US$100.

Thank you for the quick and extremely informative reply!

My display resolutions are currently below that threshold of 1920, and will likely stay that way for some time. So, luckily those $30 adapters will suffice.

I don't know if you are still typing a response, but I am still in need of understanding the following:

Having only one DP on the card, will two displays being run out of the three(DVI-I,DVI-D,HDMI) and one being run out of the DP suffice for a three monitor setup?

Thanks!

that is the way it is supposed to work, unless something about the firmware flashed in there forces a different setup.