Overclock.net banner

1 - 20 of 116 Posts

·
Registered
Joined
·
2,097 Posts
Discussion Starter #1
There seems to be a ton of confusion around here about 1) what is required for eyefinity, 2) what an active adapter is, and 3) the difference between active and passive adapters. I am making this thread, hopefully to clear that confusion.

1) Eyefinity requires an ACTIVE adapter to enable a third monitor on HD 5000 cards. Passive will NOT work, except for the first two monitors on the eyefinity 5 and eyefinity 6 cards. For the other three/four monitors, active is still required. A quick explanation of why is because DVI/HDMI requires a special clock, which the card is only able to provide two of. Displayport does not use this clock, so ATI used it as a workaround.

2) An active adapter converts a true displayport signal into DVI/HDMI/VGA/whatever else. It will have either a converter chip or a DAC built in to do said conversion. Contrary to popular belief, they do not need to have a usb power connection, in fact there are many that do not.

3) This is the big one I have been seeing a lot lately. The difference between active and passive is simple.
Passive adapters are merely a cable to go from displayport to DVI/HDMI/VGA/w.e. The video card detects the monitor as such, and outputs the required signal (DVI/HDMI/VGA). This does require one of the two aformentioned clocks, hence why they do not work with eyefinity cards.
Active adapters, on the other hand recieve a displayport signal from the video card, and convert it to DVI/HDMI/VGA. They will always have some sort of onboard DAC or video converter chip which they use to convert the dp signal. Lately, most everyone has been referring the DAC ones (which are the converters that go DP->VGA) as 'passive.' This is not the case.

Examples of passive adapters:





Examples of active adapters:


^ The one most commonly in question. There is also a newer version, which has a cable between the plugs. This is sold under several mfg. names.


^ Sapphire active displayport adapter. There are also similar versions sold by Dell and a few other companies.


^Apple mini displayport -> DVI adapter. I highly recommend avoiding this one, because it seems to only work well with apple monitors.

As far as I have seen, most DP->VGA adapters are active. I say 'most' because, while I have not seen a truly passive one, DP is still capable of outputting the signal, so there is a chance it exists.

Now, go forth and spread the word!
lol j/k. The point of this thread was to a) expose the truth (I go into OCD rage mode when I see people claiming that passive adapters work), and b) protect buyers from buying true passive adapters because they heard the DACs work.
 

·
Registered
Joined
·
635 Posts
so..... how do you explain ALL of the people claiming they got eyefinity to work using a passive DP to VGA adaptor? They are lying perhaps? Can't be 12,600 people all lying just to sell passive DP adaptors can there?

Not jumping on you or anything like that. I'm trying to get an eyefinity setup going myself and the amount of hoops you have to jump through are amazing.
 

·
Registered
Joined
·
1,085 Posts
Quote:

Originally Posted by foothead View Post
Examples of active adapters:


^ The one most commonly in question. There is also a newer version, which has a cable between the plugs. This is sold under several mfg. names.
Do you have some proof of that? I'm pretty sure its passive. I don't think its possible to produce an active adapter for a tenner.
 

·
Registered
Joined
·
2,097 Posts
Discussion Starter #4
The people claiming they use passive adapters are not truly using passive adapters. They have a DAC in them. It is just misinformation.

I can take mine apart later and post a picture of said DAC if you need.
 
  • Rep+
Reactions: ablearcher

·
Premium Member
Joined
·
7,451 Posts
Quote:

Originally Posted by Roxxas049 View Post
so..... how do you explain ALL of the people claiming they got eyefinity to work using a passive DP to VGA adaptor? They are lying perhaps? Can't be 12,600 people all lying just to sell passive DP adaptors can there?

Not jumping on you or anything like that. I'm trying to get an eyefinity setup going myself and the amount of hoops you have to jump through are amazing.

Quote:

Originally Posted by Tehrawk View Post
Do you have some proof of that? I'm pretty sure its passive. I don't think its possible to produce an active adapter for a tenner.

Quote:

Originally Posted by foothead View Post
The people claiming they use passive adapters are not truly using passive adapters. They have a DAC in them. It is just misinformation.

I can take mine apart later and post a picture of said DAC if you need.
Guys...

DP is a digital signal

VGA is an analog signal.

Conversion MUST happen, somewhere.

Just because misinformed, and some dim people, call it a passive adaptor, doesn't mean it is.

It is still actively converting the Digital DP signal, over to an Analog VGA signal.

You cannot passively convert that (not for DP to VGA).
 

·
Registered
Joined
·
2,097 Posts
Discussion Starter #6
Quote:

Originally Posted by ablearcher View Post
Guys...

DP is a digital signal

VGA is an analog signal.

Conversion MUST happen, somewhere.

Just because misinformed, and some dim people, call it a passive adaptor, doesn't mean it is.

It is still actively converting the Digital DP signal, over to an Analog VGA signal.

You cannot passively convert that (not for DP to VGA).

Actually you can, because there is no conversion going on with a passive adapter. Instead, the card outputs the intended signal.
 
  • Rep+
Reactions: ablearcher

·
Premium Member
Joined
·
7,451 Posts
Quote:

Originally Posted by foothead View Post
Actually you can, because there is no conversion going on with a passive adapter. Instead, the card outputs the intended signal.
then how come I couldn't use:

DVI
HDMI
DVI--> VGA

?

As I understand the DVI port has 5 pins on the side for analog VGA...
 

·
Registered
Joined
·
2,097 Posts
Discussion Starter #8
Sorry, i do not follow. Do you mean why you could not use tge three together?

VGA needs the same clock as DVI. This would be why.

My point was that the passive converter simply tells the card to output the signal in dvi, vga, or w/e. It still would need the clock, hance why it is not compatible with eyefinity. My point was that, assuming the clock was available, it would be able to output an analog signal.
 
  • Rep+
Reactions: ablearcher

·
Registered
Joined
·
3,222 Posts
funny the one i have says neather passive or active lol just that its a dp to vga and it works thats all that matters lol

http://www.newegg.com/Product/Produc...82E16812270275

"Model
BrandBYTECC
ModelAP-DPVGA
Spec
TypeDisplayPort to VGA
Features
FeaturesDisplayPort v1.1 Compliant

Enable high quality optional digital audio transmissions

embedded clock architecture to reduce EMI susceptibility

Support greater than QXGA (2048x1536) resolution at 24-bit color depths

Support existing VESA and CEA standards

Support hot plug and unplug detection as well as link status-failure detection

Support reduced bandwidth transmission via direct drive over a 15M cable

Supports a minimum of 1080P resolution at 24bpp, 50/60Hz at 15 M

Support conversion from DisplayPort signal to VGA signal

Support DisplayPort connector 20pins

Support 8-bit & 10-bit deep color

Support the video bandwidth up to 10.8Gbps

Support the 1Mbps' bidirectional auxiliary channel

Support the 1 lane, 1 direction, 4 lines connection"
 

·
Registered
Joined
·
1 Posts
Hi,

I got HD5750, the BYTECC 3 ft Mini DisplayPort Male to DisplayPort Male Video Cable Model DPR-03
http://www.newegg.ca/Product/Product...tent-_-text-_-

connected it to iMAC27".

Does not work: It probably gets the signal, because it goes dark for ~20sec while my PC with the Sapphire flickers during this time. Then everything return back to default.

I contacted the support from Sapphire and they suggest i need an active display port adapter which I can't understand, as all I am doing is sending a signal from displayport (HD5750) to mini displayport (iMAC27).

What do you think and recommend to solve the problem?

Thank you!
 

·
Registered
Joined
·
1 Posts
I have an Early 2009 Mac Mini with Mini DVI and Mini DisplayPort. And I have two 1080p HDTVs. The Mac Mini is capable of dual display, and I've gotten it to work before, so the issue is not the TV or Mac. And I have tried both Mirroring and No Mirroring.

I got a Mini DisplayPort to HDMI Adapter (#5311) and a Mini-DVI to HDMI Adapter (#4852) both from MonoPrice. And for some reason I can't get the Mac Mini to dual display, it's only one or the other.

Before I had a Mini Displayport Male and USB Male AUDIO to HDMI Female Converting Adapter (#5969) and I got video on both HDTVs, but not audio at the same time b/c one was USB and one was TOSLINK.

I'm not sure why I can't get video on both monitors.
 

·
Registered
Joined
·
1 Posts
I too am having the same problem as the user above (apple_pc). I got a Radeon HD5750 and bought a DP to Mini DP Cable (similar model) as above and connected it to the iMAC27". Same problem - it gets its signal and then goes dark for 20 seconds before returning to default. I probably have a passive adapter cable too. But I don't know where to purchase an active adapter DP to mini DP cable. Can anyone assist and does anybody know if this will really work? Thank you!
 

·
Registered
Joined
·
4,096 Posts
Quote:

Originally Posted by ozzren View Post
I too am having the same problem as the user above (apple_pc). I got a Radeon HD5750 and bought a DP to Mini DP Cable (similar model) as above and connected it to the iMAC27". Same problem - it gets its signal and then goes dark for 20 seconds before returning to default. I probably have a passive adapter cable too. But I don't know where to purchase an active adapter DP to mini DP cable. Can anyone assist and does anybody know if this will really work? Thank you!
make a new thread about this instead of hijacking this one.
 

·
Registered
Joined
·
1 Posts
Hi Guys

Recently got my 3 monitors and have run into some difficulty.

I have two monitors running on DVI and the 3rd is display port to HDMI

When i plug in all 3 i only get signal on the two DVI displays but if i plug in just the display port i get signal... any ideas? Im assuming i have a passive adapter but i had read that you only needed active adapters for monitors that were 30" and up

Any help would be awsome.... but looks like i might need to go buy an active adapter.....
 

·
Registered
Joined
·
97 Posts
hello, hopefully someone could answer, even though this thred is somewhat old
smile.gif

I've been looking at dvi-dp adaptors to get my third monitor to work (all 3 is currently in dvi-dp passive adaptors)... thing is i can find roughly 2 kinds of active adaptors 1 with the extra usb connection at about 90$ and some without the usb at 30$, the cheap ones says that it's active but i'm confused about the price difference! is the normal cheap adaptors that says active on the package enough to get eyefinity to work even though they do not have external power?
 

·
Something witty
Joined
·
2,400 Posts
Quote:
Originally Posted by Panickypress View Post

hello, hopefully someone could answer, even though this thred is somewhat old
smile.gif

I've been looking at dvi-dp adaptors to get my third monitor to work (all 3 is currently in dvi-dp passive adaptors)... thing is i can find roughly 2 kinds of active adaptors 1 with the extra usb connection at about 90$ and some without the usb at 30$, the cheap ones says that it's active but i'm confused about the price difference! is the normal cheap adaptors that says active on the package enough to get eyefinity to work even though they do not have external power?
I'm just about to test a 5 display system with the cheaper non-usb adapters. I'll report my findings.
 

·
Registered
Joined
·
44 Posts
I know there are other threads that cover this, but it seems like clear answers haven't exactly been given regarding the latest adapters...

If the adapter is not specifically labeled as Active, and it does not have an extra USB cable to provide power, the odds are it is passive. I tried a generic one like this when I couldn't find something specifically labelled as active at my local shops. What you will see is that your CCC shows three monitors connected, but you can only run 2 at a time. It will be impossible to setup a three monitor eyefinity group.

When you have an actual active adapter, you will see three monitors in CCC again, but you can actually expand your desktop or clone to all three at the same time, no issues. You will also be able to setup an eyefinity group as well with no issues.

The cheapest ACTIVE adapter I found locally was the XFX one. No USB needed, just a display port, short cable (4" or so) and DVI port. Max res is 1900x1200 with this type. If you need a higher res, you will need one of the expensive usb powered active adapters. Example usage would be for running dual-link DVI monitors like 30" 2560x1600 beasts... If you can afford multiple ones of those, you can afford the better adapter. :)

NewEgg has a few to choose from in the $25 - $39 range. Saphire has some without USB now, as well as some other off-brand companies. Even more helpful, some are actually stating on their packaging if they are eyefinity compatible. In most cases, they appear to be correct. :)

Anyway, my testing was done with 5870's going to DVI only monitors. I'm about to test one more variable when I hook up my 5970 in eyefinity mode. I need a mini-displayport to regular displayport, then my active dp adapter to go to my DVI connection. Wish me luck... ;)

Have fun!
 
1 - 20 of 116 Posts
Top