HDMI for high-res monitors: ATI vs nVidia

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ciobi

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According to the specs on AMD's site, Radeon HD cards can only do 1920x1200 on an HDMI cable. OTOH nVidia apparently doesn't have this limitation on its 2xx cards.

Can anybody who actually tried the HDMI connection on 2560x1600 or 2560x1440 monitors share the experience? (Mainly what works / doesn't work.)

Thanks
 
ciobi said:
According to the specs on AMD's site, Radeon HD cards can only do 1920x1200 on an HDMI cable. OTOH nVidia apparently doesn't have this limitation on its 2xx cards.

Can anybody who actually tried the HDMI connection on 2560x1600 or 2560x1440 monitors share the experience? (Mainly what works / doesn't work.)

Thanks
Click to expand...

Do monitors that res even run through hdmi? I thought only dual link DVI had enough bandwidth. Not exactly sure the max bandwidth of hdmi though.
 
I can check for you but I dont know how accurate this would be. My GTX 280s do not have a HDMI output as you probably know. They did however come with converters to switch the DVI-D DL connections to HDMI. I can check that for you but something tells me it will work at 2560x1600.
 
Hmm I thought HDMI 1.3a doesn't support 2560x1600, i think it only supports up to 1920x1200?

The HDMI specification defines the protocols, signals, electrical interfaces, and mechanical requirements of the standard.[38] The maximum pixel clock rate for HDMI 1.0 was 165 MHz, which was sufficient for supporting 1080p and WUXGA (1920×1200) at 60 Hz. HDMI 1.3 increased that to 340 MHz, which allows for higher resolution (such as WQXGA, 2560×1600) across a single digital link.[39] An HDMI connection can either be single-link (Type A/C) or dual-link (Type B) and can have a video pixel rate of 25 MHz to 340 MHz (for a single-link connection) or 25 MHz to 680 MHz (for a dual-link connection). Video formats with rates below 25 MHz (e.g., 13.5 MHz for 480i/NTSC) are transmitted using a pixel-repetition scheme.[1]

guess I'm wrong! I don't see why ATI would have a limitation ,as long as it's HDMI port is 1.3 and follows hdmi specs
 
FranklyShankly said:
Do monitors that res even run through hdmi? I thought only dual link DVI had enough bandwidth. Not exactly sure the max bandwidth of hdmi though.
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According to the specs, HDMI 1.3 (released in 2006) supports 2560x1600. The problem is that the HDMI specs are quite meaningless in determining what a product can do, as vendors are allowed to implement whatever parts of the specs that they feel like, while still claiming 1.3 compatibility. So you can't really draw any conclusion from the fact that a monitor or a card is 1.3. So that's why I'm inquiring about real-world experiences.
 
Don't use HDMI for your 2560x1600 monitor. Problem solved.

Are there even any 2560x1600 monitors that can take a 2560x1600 HDMI input? And why do you want to use HDMI over DVI?
 
kllrnohj said:
Don't use HDMI for your 2560x1600 monitor. Problem solved.

Are there even any 2560x1600 monitors that can take a 2560x1600 HDMI input? And why do you want to use HDMI over DVI?
Click to expand...

Maybe he has a 30" monitor that is not HDCP compliant over dual link DVI. Or maybe not. :D
 
kllrnohj said:
Don't use HDMI for your 2560x1600 monitor. Problem solved.

Are there even any 2560x1600 monitors that can take a 2560x1600 HDMI input? And why do you want to use HDMI over DVI?
Click to expand...

Dell 3008 WFP... I would check but I do not have the DVI to HDMI converters with me... arg
 
FYI, here is how HDMI->DVI conversion works:

DVI Single Link uses 19 pins and supports up to 1920x1200 at 60Hz, but is not fast enough to support 2560x1600 or 2560x1440 at 60Hz, or 1680x1050 at 120Hz.

DVI Dual Link adds 6 more pins to the original 19 to support 2560x1600 and 2560x1440 at 60Hz, and 1920x1080 at 120Hz. (Higher resolutions and Hz are irrelevant at this time because no monitors offer them and probably will not for a very long time, if ever.)

HDMI uses the same 19 pins as DVI Single Link for video (plus other pins for audio), but is able to support the higher resolutions and Hz through those 19 pins.

HDMI is able to pass DVI Single Link through its 19 video pins, making conversion extremely simple with no data loss. However, HDMI is not able to pass DVI Dual Link through because it has no way of passing through the extra 6 pins that DVI Dual Link requires. Therefore, when using an HDMI->DVI cable, you will have the same resolution and Hz restrictions as DVI Single Link.
 
kllrnohj said:
Don't use HDMI for your 2560x1600 monitor. Problem solved.

Are there even any 2560x1600 monitors that can take a 2560x1600 HDMI input? And why do you want to use HDMI over DVI?
Click to expand...

U2711 looks like a 2560x1440 monitor that might take a 2560x1440 over HDMI. Whether it does so - that's a different question to ask.

I want to use it because HDMI 1.3 allegedly allows 30 bit colors while DVI doesn't.

I saw no big issue with monitors taking 2560x1600 on HDMI, as HDMI is electrically compatible with DVI. But after looking at the connector pinouts, HDMI turns out to be single-link. So the 2560x1600 on HDMI requires higher data rates than DVI single-link is supposed to handle, as evilsofa already pointed out.

So maybe 2560x1600 is just a part of the HDMI 1.3 spec that nobody bothered to implement ... Well, I started this thread hoping to find if this is so.
 
ciobi said:
So maybe 2560x1600 is just a part of the HDMI 1.3 spec that nobody bothered to implement ... Well, I started this thread hoping to find if this is so.
Click to expand...

HDMI 1.3 supports 24-bit 2560x1600 at 75Hz; HDMI 1.2a and earlier only supported up to 1920x1200 at 60Hz.

HDMI 1.3 optionally supports 30-bit 2560x1600 at 60Hz, 36-bit 1920x1200 at 75Hz and 48-bit 1920x1200 at 60Hz. When looking for video cards and monitors that support 30-bit 2560x1600, look for Deep Color support and assume that it doesn't support it if it doesn't say so.

HDMI 1.3 does not support 1920x1080 at 120Hz.
 
evilsofa said:
HDMI 1.3 supports 24-bit 2560x1600 at 75Hz; HDMI 1.2a and earlier only supported up to 1920x1200 at 60Hz.

HDMI 1.3 optionally supports 30-bit 2560x1600 at 60Hz, 36-bit 1920x1200 at 75Hz and 48-bit 1920x1200 at 60Hz. When looking for video cards and monitors that support 30-bit 2560x1600, look for Deep Color support and assume that it doesn't support it if it doesn't say so.

HDMI 1.3 does not support 1920x1080 at 120Hz.
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I'm pretty sure 24-bit 2560x1600 in HDMI 1.3 is optional as well.
 
I tried using my 5870's HDMI, The only options I had was 1080P and down, and it looks all smudged to boot.

My monitor does 1920x1200. (It does 1:1 and Aspect.) I wanted to use the DVI-D input for 1 PC and the HDMI for another so I can use both computers on 1 KB/M & monitor.

I never did figure out why it looked like poo. If I want a clear picture on both, I have to use the DVI-sub. (VGA.) :(
 
Little_4nic8er said:
I tried using my 5870's HDMI, The only options I had was 1080P and down, and it looks all smudged to boot.

My monitor does 1920x1200. (It does 1:1 and Aspect.) I wanted to use the DVI-D input for 1 PC and the HDMI for another so I can use both computers on 1 KB/M & monitor.

I never did figure out why it looked like poo. If I want a clear picture on both, I have to use the DVI-sub. (VGA.) :(
Click to expand...

The HDMI output might be expecting you to hook it into a TV and thus has overscan enabled. I've never used it, so I don't know for sure, but it would be something to check.
 
I played with overscan but it didn't help unfortunately. I'll be getting an HDTV in a few weeks and will see if it looks better on that. The PS3 looks great on this monitor through the HDMI. Though I have to use the PS3 to component converter to get sound through my PC speakers as this monitor has none.
 
ciobi said:
According to the specs on AMD's site, Radeon HD cards can only do 1920x1200 on an HDMI cable. OTOH nVidia apparently doesn't have this limitation on its 2xx cards.

Can anybody who actually tried the HDMI connection on 2560x1600 or 2560x1440 monitors share the experience? (Mainly what works / doesn't work.)

Thanks
Click to expand...

NVidia cards have the same limitation. Least my BFG 275GTX can only do 1920x1200 on an HDMI Cable.
 
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