Passive Displayport adapter with Eyefinity and VGA adapter

[blanketyblank]

I've been looking through some sites, and noticed that at least one person was succesfully able to use a passive displayport to VGA adapter to get a 3 monitor eyefinity setup working.
I'm wondering if it's possible to do the same with a passive displayport to DVI if you use a DVI to VGA plug on one of the other monitors.
Right now an active adapter is too expensive for me to consider, but passive ones are cheap enough though still kind of pricy for what it does. I've already got a lot of DVI to VGA adapters which is why I'd prefer doing this than getting a DP2VGA. I'd appreciate it if anyone with an eyefinity setup would let me know.

 

[manimal]

I've been looking through some sites, and noticed that at least one person was succesfully able to use a passive displayport to VGA adapter to get a 3 monitor eyefinity setup working.
I'm wondering if it's possible to do the same with a passive displayport to DVI if you use a DVI to VGA plug on one of the other monitors.
Right now an active adapter is too expensive for me to consider, but passive ones are cheap enough though still kind of pricy for what it does. I've already got a lot of DVI to VGA adapters which is why I'd prefer doing this than getting a DP2VGA. I'd appreciate it if anyone with an eyefinity setup would let me know.

As far as I had seen you need an active adapter....period...

 

[NoQuarter]

http://www.widescreengamingforum.com/forum/viewtopic.php?t=17468
http://www.tomshardware.com/forum/279385-33-success-eyefinity-passive-adapter

I'd originally thought the DP adapter needed to be active to provide a clock signal for the display but more reading made it sound like the passive DP->DVI adapters were single link and couldn't handle the resolution or something, and that only the active DP->DVI adapters were dual link which provides for higher resolutions with proper signal (up to 2560x1600 w/GTF).

If this is true then a passive DP->DVI adapter should work at lower resolution (1600x1200 resolution with GTF blanking). But if it's true it also means you'll lose the high resolution capability when you go from DP->DVI->VGA due to the single link.


But I've never read anything about a passive DVI working so no idea (even the VGA method is suppose to have some blank screen glitch.)

edit: after reading the DP->VGA adapter again it still sounds like my original assumption, that the adapter has to generate the clock/de-packet the data is true. Apparently the DP->VGA adapter has a chip in it that does this. A DVI->VGA adapter won't have this chip so neither the DP->DVI step or DVI->VGA step has the proper chip for converting the signal, only the DP->VGA one or an active DP->DVI does.. when you use a truly passive adapter it just relies on the GPU to send the 'other' signal, but in this case there aren't enough TDMS/RAMDAC units to send another DVI or VGA signal.

 

[blanketyblank]

Thanks for the info. Guess I can't cheap out after all.

 

[trugate]

Doesn't this link prove that SOME passive adapters work? It's a list of validated adapters right on their site for use with eyefinity... and a good portion of them are listed 'passive' right on there.

http://support.amd.com/us/eyefinit [...] ngles.aspx

I'm just trying to clarify, as there is so much mixed information regarding eyefinity and passive adapters. From what I understand, the problem with passive adapters is the bandwidth limitation by not being pushed by an external source, like the usb port, and as such cannot drive a high resolution through it (past 1080p equivalent in most cases), not just that it 'wont work'.

I don't really want to spend upwards of $100 just because everyone else may be going on a misconception. Does anyone have a definite answer with first hand experience?

 

[aka1nas]

Doesn't this link prove that SOME passive adapters work? It's a list of validated adapters right on their site for use with eyefinity... and a good portion of them are listed 'passive' right on there.

http://support.amd.com/us/eyefinit [...] ngles.aspx

I'm just trying to clarify, as there is so much mixed information regarding eyefinity and passive adapters. From what I understand, the problem with passive adapters is the bandwidth limitation by not being pushed by an external source, like the usb port, and as such cannot drive a high resolution through it (past 1080p equivalent in most cases), not just that it 'wont work'.

I don't really want to spend upwards of $100 just because everyone else may be going on a misconception. Does anyone have a definite answer with first hand experience?

My understanding that it wasn't just a bandwidth issue, but that the device has to actually support DVI signaling on a displayport to use a passive adapter and the 5xxx series does not do so.

 

[trugate]

Yah, after reading even further, it seems that a passive adapter to VGA will work just fine (uses RAMDAC), but not to hdmi or dvi, those require active adapters as the card is already handing out the maximum dvi/hdmi signals it can do.

I'll probably just use a passive vga to one of my 22" lcd's, during gaming it won't be a noticeable difference from DVI.

Thanks for the reply though, good to hear it verified a little bit. I think, that since eyefinity is advertised like it is, they should PLAINLY state these details, or just make everything work for up to four displays like one would assume it's capable of. Lots of research was done so I won't be making a bad purchase!

 

[VirtualLarry]

My understanding that it wasn't just a bandwidth issue, but that the device has to actually support DVI signaling on a displayport to use a passive adapter and the 5xxx series does not do so.

I don't get it. Then why is this dongle listed in ATI's validated list?

Accell B087B-001B N/A DisplayPort DVI (Single Link, Passive Dongle) 1920x1200 Validated accellcables.com

Passive, displayport to DVI? Or did I misread it and it's a DVI to displayport?

Edit: I guess ATI has the wrong specs on that dongle, it's an active dongle, not a passive one, according to the product model code. http://www.accellcables.com/products/DisplayPort/DP/dp_dvi.htm

 

[gorobei]

that accell dongle seems to be getting it's power from the dport rather than a usb draw.

whether that counts as passive or active in amd's view is probably the confusion. either way, retailers are charging $30 for it. so the price is far more reasonable than the apple active dongles. it should get even cheaper as production increases.

Mind you this is probably a limited time item. As more monitor manufacturers transition over to dport, the demand for these things will drop and fewer companies will produce them. But that is probably more than a few years away.

I really hope some review site(hardocp,anand,etc) does a follow up review on eyefinity and these adapters. Hopefully amd will get new drivers out with bezel compensation and ability to use different size/resolution monitors. Maybe when eyefinity6 is released.

 

[MaDAdiii]

So here's my problem guys i have a ATI 5850 card with 4 ports - 2DVI's, an HDMI and a display port. I've been reading all the forums and trying to put together what i need and so i did...but it didnt really help so please tell me what i'm doing wrong.

I have both my DVI's connected to my 2 monitors now i want to use my display port as my third output for an extended desktop on my "TV" so i went and bought a display port to HDMI convertor from Dell

http://accessories.dell.com/sna/prod...1&sku=A1982952

but the thing is it still dosent let me have a 3x1 configuration it tells me that i have to disable one of my desktops in order for me to get my 3'rd display that is my TV running....so by the end of it i have only 2 displays running at the same time and not 3..what cant Eyefinity work? or do i have the wrong adapter?

 

[NoQuarter]

Hmm, link doesn't work. My guess is it's not an active adapter though.. active adapters are ~$100 with the exception of the active VGA adapters which are ~$30 so if you didn't spend $100 on it it's probably not active (I also don't remember seeing any active DP->HDMI)

 

[daddy-o]

Does the monitor not have a VGA port? I'm using the passive VGA->DP adapter in my eyefinity setup, and I cannot tell visually which one is the VGA screen, if that is your concern.

 

[yh125d]

Why the hell didn't ATI just put 3 DVI/HDMI? I remember something about having only two digital display controllers or something... well get off your arse and put 3 in there! It can't be that damn hard...

 

[gorobei]

Why the hell didn't ATI just put 3 DVI/HDMI? I remember something about having only two digital display controllers or something... well get off your arse and put 3 in there! It can't be that damn hard...

from a 'down the road' point of view there is no point to adding more tmds timing signal generators. Eventually all monitors will be equipped with displayport. it's cheaper than hdmi, has better performance, and eliminates redundant panel circuitry. Future amd cards will only need the displayport paths so even the current 2 timing generators will be unnecessary.(i.e. the 5870 eyefinity6 with 6 mini-dPort ports, and no dvi/hdmi)

If you have enough money for the 5xx0 card, 3 monitors, and a desk big enough for the whole rig; then you either have or can afford monitors with dPort. so the target audience of enthusiasts wouldnt need dPort dongles/signal generators. This generally only punishes people trying to do budget versions of eyefinity with semi-recent equipment. Oddly those with really older vga equipment are the only ones who can do eyefinity on the cheap.

 

[MaDAdiii]

Hmm, link doesn't work. My guess is it's not an active adapter though.. active adapters are ~$100 with the exception of the active VGA adapters which are ~$30 so if you didn't spend $100 on it it's probably not active (I also don't remember seeing any active DP->HDMI)

Ok so what are "ACTIVE" adapters? my theory on this is that active adapters are those that covert signals from say a display port to an HDMI port coz the two ports send different signals right? So this is what i did then i disabled my secondary monitor that was connected to my DVI and hence i was able to run my TV (since i could only have 2 displays running at the same time) and when i played a file that was outputting video to my TV i could get both sound (from my TV speakers) and video off my TV (since my TV is connected via a HDMI cable to the convertor that is hooked up to my display port on my video cad. So dosen't this make it an active adapter if its converting the signal?

 

[yh125d]

from a 'down the road' point of view there is no point to adding more tmds timing signal generators. Eventually all monitors will be equipped with displayport. it's cheaper than hdmi, has better performance, and eliminates redundant panel circuitry. Future amd cards will only need the displayport paths so even the current 2 timing generators will be unnecessary.(i.e. the 5870 eyefinity6 with 6 mini-dPort ports, and no dvi/hdmi)

If you have enough money for the 5xx0 card, 3 monitors, and a desk big enough for the whole rig; then you either have or can afford monitors with dPort. so the target audience of enthusiasts wouldnt need dPort dongles/signal generators. This generally only punishes people trying to do budget versions of eyefinity with semi-recent equipment. Oddly those with really older vga equipment are the only ones who can do eyefinity on the cheap.

No point in having more than 2 DVI/HDMI connections? You gotta be kidding me... DP is nowhere near close to superceding anything yet, and it would have been a very smart move for ATI to put a 3rd. Have you not seen all the threads over the last 6 months talking about how you have to use DP for eyefinity? It's ridiculous, and ATI is shoving it down our throats (if we want eyefinity). If they ya know, actually wanted their feature to be used more, they would have done the smart thing and made it simple for the end user to handle.

 

[NoQuarter]

Ok so what are "ACTIVE" adapters? my theory on this is that active adapters are those that covert signals from say a display port to an HDMI port coz the two ports send different signals right? So this is what i did then i disabled my secondary monitor that was connected to my DVI and hence i was able to run my TV (since i could only have 2 displays running at the same time) and when i played a file that was outputting video to my TV i could get both sound (from my TV speakers) and video off my TV (since my TV is connected via a HDMI cable to the convertor that is hooked up to my display port on my video cad. So dosen't this make it an active adapter if its converting the signal?

Well, HDMI and DVI use the same signal, so the adapter there is a passive one it just rearranges the plugin. An active DP adapter has a chip in it that generates a clock signal and unpacks the DP packet data since DP doesn't use a clock signal and uses a packeted data stream.

When you use a passive DP adapter all it does is tell the GPU to send the standard TDMS DVI/HDMI signal out the DP output and all the adapter does is rearrange the wires again.

 

[slayernine]

I have both a passive and an active display port adapter. As of my current drivers you still need the stupidly expensive active adapter.

 

[daddy-o]

I'm using 10.3 Cats and a passive VGA-DP adapter at 1680x1050 X 3 and it works like a champ.

 

[NoQuarter]

I have both a passive and an active display port adapter. As of my current drivers you still need the stupidly expensive active adapter.

Yup no driver can fix it it's a hardware limitation. For them to include a 3rd clock gen on the GPU die would have increased the size and cost of the GPU for a feature only a small % would use.

It woulda been nice to include it but I can see why they didn't, and most people upgrading to 3 monitors to use it can pick up a DP monitor on the way.