TR Forums

Both AMD and Nvidea make cards that support 6 or 8 displays... via DisplayPort. But, of course, those cards are mostly used in digital signage applications where the displays typically don't have DisplayPort inputs, but do have multiple HDMI inputs.

So, 2 questions:

1.) Why?? For the love of God, man, why, Why, WHY??? (as in: why the hell don't they at least make a version of those cards with 6 or 8x miniHDMI ports instead??)

2.) um, anyone know of a video card with 6 or 8x miniHDMI ports?

Thanks, fellow gerbils!

Matrox do a C900 model that provides 9 HDMI outputs, although they only support up to 1920x1200 each.

http://www.matrox.com/graphics/en/produ ... ries/c900/

EndlessWaves wrote:

Matrox do a C900 model that provides 9 HDMI outputs, although they only support up to 1920x1200 each.

http://www.matrox.com/graphics/en/produ ... ries/c900/

Yikes. A $2000 video card seems a bit extreme...

Can't DP be adapted to HDMI relatively cheaply and easily? Perhaps that's why they use it... DP and Mini-DP adapters are very common, probably because Apple computers and most workstations (Lenovo, Dell, HP, etc.) only have DP, so it is a common interface.

ozzuneoj wrote:

Can't DP be adapted to HDMI relatively cheaply and easily?

Yes, it can, and that's our default solution right now. It just seems silly that AMD and Nvidea make cards that are mostly used with HDMI displays with only DP ports...

Ironically, BTW, miniDP-to-HDMI adaptor cables are actually less expensive than miniHDMI-to-HDMI cables - go figger!

EndlessWaves wrote:

they only support up to 1920x1200 each.

In the immortal words of The Monks: 'Nice legs, shame about 'er face'

EndlessWaves wrote:

Matrox do a C900 model that provides 9 HDMI outputs, although they only support up to 1920x1200 each.

http://www.matrox.com/graphics/en/produ ... ries/c900/

That's probably not Matrox's fault. IIRC early revisions of HDMI only ever supported 1920x1200 maximum.

Along with the other posters, I'm thinking that getting a mini-DP to HDMI converters is the best bet here. Although they may need to be active depending on features needed.

Nope but there are mini-DP options as you've pointed out.

HDMI is shunned in this space for several reasons. The first is cost as there is a per port HDMI licensing fee so it is partially for cost reasons. Secondly is that DP/mini-DP support higher resolutions (up to 8K30 right now via DP 1.4). Third, it is reportedly easier to frame lock multiple DP based displays together without an external clock signal. Lastly, several professional level displays will come with integrated MST hubs so that daisy chaining multiple units via DP is possible. The good news is that all the mini-DP ports can be adapted to HDMI via active adapters. I strongly recommend you use the same brand and model of active adapter for each port converted to HDMI.

The other factor is that for really big video wall applications, DVI is still popular but is being replaced mainly by DisplayPort. The early 4K generation wall processors used dual link DVI to provide 4K30 support on an input. HDMI is being skipped over as the packetized nature of DP signalling permits easy routing between LED tiles on the controller side. Using DP here helps reduce latency, a troublesome thing to deal with in LED applications.

DisplayPort is compatible with Thunderbolt and therefore more flexible for use in computing applications in general.

HDMI was designed primarily for AV devices, and it shows.

1. DisplayPort has supported variable refresh rates (VESA adaptive sync) for years; HDMI just added support for VRR in January of this year, and I'd be surprised if many devices even support it yet.

2. DisplayPort could do 2x 4K @ 60 Hz since 2014. HDMI could only do one until this year.

3. DisplayPort supported 8K a year before HDMI did.

Any PC-related functionality has been incorporated into DisplayPort in a much more timely fashion. If you want to support the best displays and play at the high end of the market, you could not compete by offering only HDMI/mini-HDMI.

Once it became the standard for PCs, it becomes difficult to justify the additional space for HDMI connectors, especially since DisplayPort can support HDMI-out with a passive adapter---the reverse is not true. (Note the "can"; the standard does not require that all DisplayPort outputs support it.)

TheRazorsEdge wrote:

DisplayPort is compatible with Thunderbolt and therefore more flexible for use in computing applications in general.

This is actually backward. Thunderbolt is mandated to be backwards compatible with DisplayPort.

TheRazorsEdge wrote:

HDMI was designed primarily for AV devices, and it shows.

HDMI was born from DVI which uses the same basic signaling (hence passive HDMI to DVI adapters). The consumer market added two things to the initial spec that DVI did not have: encapsulated PCM audio and HDCP copy protection.

Professional AV gear of that time continued to utilize DVI as those two features were not hard requirements for connectivity or production purposes. While the consumer side of HDMI evolved to support high clock speeds, the professional side simply adopted dual link DVI and begun to support HDCP for ease of bringing in an HDMI signal here necessary. The newest generation of professional gear are adopting DP natively where as the consumer side is still focused on HDMI.

TheRazorsEdge wrote:

1. DisplayPort has supported variable refresh rates (VESA adaptive sync) for years; HDMI just added support for VRR in January of this year, and I'd be surprised if many devices even support it yet.

Adaptive sync is an optional extension for DP. Similarly it is not a hard requirement either on the HDMI. DP was able to incorporate variable refresh in a pretty straight forward manner due to how DP utilized a self clocking signal. HDMI on the other hand has dedicated pins for the clock signal.

TheRazorsEdge wrote:

2. DisplayPort could do 2x 4K @ 60 Hz since 2014. HDMI could only do one until this year.

This is incorrect. DP 1.4 with DSC has enough bandwidth to drive two 4K displays at 60 Hz but the hardware to support that was only released in 2016. This still isn't technically possible either as there are no DP 1.4 MST hubs on the market.

HDMI 2.1 has enough bandwidth to do this in the spec but it would require utilizing Twin View which carries some complexity. Twin View essentially splits the data stream as if it were a 3D display but the signal for each eye is not bound to a single display.

The only way to get two 4K @ 60 Hz displays out of one physical connector today is via Thunderbolt 3 which encapsulates two full independent DP 1.2 streams. Even then, this is optional (Thunderbolt 3 only requires a single DP stream to be encapsulated) and thus some Thunderbolt 3 ports are limited to a single 4K display output.

TheRazorsEdge wrote:

3. DisplayPort supported 8K a year before HDMI did.

Two and a half years if you go by when each spec was ratified.

If you go by shipping hardware, HDMI 2.1 gear has not yet arrived on the market so 8K via HDMI is yet not possible. The first HDMI 2.1 capable hardware is not expected until late 2018 which would still be two years.

TheRazorsEdge wrote:

Any PC-related functionality has been incorporated into DisplayPort in a much more timely fashion. If you want to support the best displays and play at the high end of the market, you could not compete by offering only HDMI/mini-HDMI.

The real problem HDMI is running into is bandwidth over copper cabling. Active HDMI and active-fiber cables are not formally part of the HDMI spec and only conform to a specific version (ie fiber HDMI 1.4 cables cannot work at HDMI 2.0 speeds). These active cables are also directional which complicates installation.

DP on the other hand does support active cabling as part of the spec to support longer distances and higher bit rate. The core reason for DP's greater flexibility here is that it mandates a far higher auxiliary power to supplement these features.

TheRazorsEdge wrote:

Once it became the standard for PCs, it becomes difficult to justify the additional space for HDMI connectors, especially since DisplayPort can support HDMI-out with a passive adapter---the reverse is not true. (Note the "can"; the standard does not require that all DisplayPort outputs support it.)

Passive adapters are actually an optional part of the DP spec (formally DP++). Active adapters will always work for converting DP to HDMI though.

As an aside, I've always considered it a bit of an anomaly that my circa-2008 AM2+ motherboard (Asus M3A78-CM) has a DP port for the IGP. DP wasn't all that common back then, let alone as a feature on an inexpensive micro-ATX motherboard. Real workhorse of a mobo too; it's still in use to this day running my file server, and has never skipped a beat. (So the DP connection and the excellent VIA onboard audio implementation are going to waste. I think Realtek is finally catching up to where VIA was a decade ago with onboard audio solutions.)

ozzuneoj wrote:

EndlessWaves wrote:

Matrox do a C900 model that provides 9 HDMI outputs, although they only support up to 1920x1200 each.

http://www.matrox.com/graphics/en/produ ... ries/c900/

Yikes. A $2000 video card seems a bit extreme...

Can't DP be adapted to HDMI relatively cheaply and easily? Perhaps that's why they use it... DP and Mini-DP adapters are very common, probably because Apple computers and most workstations (Lenovo, Dell, HP, etc.) only have DP, so it is a common interface.

My older AMD had 5 outputs.
After 2 were used I had to Active Display Port adapters (when going from DP to other) . The listed DP are all Mini-DP.
I had 1 HDMI hooked up to HDMI, 1 DP passive adapter to HDMI, and the third needed me to buy an active DP to HDMI. Another Passive DP to HDMI did not work.
You have to see what the card allows.

just brew it! wrote:

As an aside, I've always considered it a bit of an anomaly that my circa-2008 AM2+ motherboard (Asus M3A78-CM) has a DP port for the IGP.

Dell has been doing that since at least the mid-00s on business-grade desktops (e.g. Optiplex line), VGA+DP output. Workstations had (and continue to have) Quadro or FirePro cards with 2+ DP outputs. Laptops were VGA+HDMI for a while, then HDMI+miniDP.

For everything else, there's AdapterCord.

ludi wrote:

just brew it! wrote:

As an aside, I've always considered it a bit of an anomaly that my circa-2008 AM2+ motherboard (Asus M3A78-CM) has a DP port for the IGP.

Dell has been doing that since at least the mid-00s on business-grade desktops (e.g. Optiplex line), VGA+DP output. Workstations had (and continue to have) Quadro or FirePro cards with 2+ DP outputs. Laptops were VGA+HDMI for a while, then HDMI+miniDP.

For everything else, there's AdapterCord.

I guess that kind of makes sense. The M3A78-CM was part of Asus' "Corporate Stable" product line, so nominally aimed at the business desktop market.