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silent-circuit · (Last edited: 10-16-2015, 04:22 PM by silent-circuit)

I realize I'm way outside the bounds of what this combination is "supposed" to do, but that's what people seem to do here -- push it -- so I'm hoping I'm in the right place.

I've got the TV hooked up via a passive HDMI to DVI adapter (one of the little screw-on things) to a known high quality DVI dual link cable connected to the first DVI port on my primary 6950. The other card is in Crossfire using 2 bridges -- I read that this is required for higher pixel clocks in some cases.

First question is, is there any reason I'd be better off using a straight HDMI cable, from the card's HDMI port to the TV? I figured since the card is HDMI 1.4 and everything I read says you need 2.0 to get 3840x2160 I would be better using the DVI port and the adapter, but maybe I'm wrong there?

Initially the display only showed 1080P as an option, but after patching pixel clock with the AMD utility available here and then using CRU to set a custom resolution, it is /supposedly/ running at 3840x2160 @ 60 Hz.

The problem is it really, really doesn't feel like 60Hz, it feels crazy slow, maybe even under 30Hz. There was always some mouse lag with this display but now there's not just a delay -- I literally see the cursor "strobe" across the screen when moving it.

That said I've literally never used a display this high res or this big before, so I don't know what to expect. Is this normal behavior for Windows? Am I not running the res I think I am? Is there any way to check other than the Windows Screen Resolution page? If I go in to the Advanced options under Monitor there it says 60 and will let me set 59, etc, but 30Hz and 60Hz feel basically the same. I can certainly tell the difference between 30 and 60 FPS, so this is throwing me off big time.

It's probably worth noting that I haven't tried to game on this display since the resolution switch, so I'll come back shortly with impressions there and see if 30/60 makes a difference. The whole "strobing mouse cursor" thing just has me confused.

Alright, after a little more messing around I realized the display gives info on audio and video format right after you change inputs.

Based on this, it's running 2160P (full res at least, yay?) at 30Hz despite Windows reporting 60Hz set. It's probably worth noting I turned Crossfire off just to be safe.

Is there any way around this limitation? I was under the (apparently mistaken) impression that the pixel clock patch would fix it.

Will I have to get a new GPU if I go to a 4K display, or do you think it's an issue with this model of TV specifically?

My understanding with continued research is it won't run 4:4:4 chroma 4k @ 60Hz from a PC anyway -- or at least no one has managed it yet -- I'd love to be the first! -- so I will probably be exchanging it for the much more expensive Samsung 40" 4K.

Before I do that though I'd love to know if my cards can even push the res in Windows at 60Hz -- or do I really need a new Nvidia 9 series as bad as people say?

A little more info.

2160p@30Hz via the DVI port via DVI cable and passive HDMI adapter
2160p@30Hz via the HDMI port with a straight HDMI cable (not an officially 2.0 qualified cable, but it's like 6 ft and good quality)

HDMI port used on the TV also doesn't seem to matter, though I've read many places that on these lower end sets (and on most sets really at this point) there's only one that's really HDMI 2.0. Sadly, despite reading a few places that that's the case with this set, I haven't seen anyone clearly state which port is supposed to work...

This is with pixel clock patched and CRU set custom res.

So far nothing lets me get 60Hz.

Would love some help with that.

Frustration is setting in -- am I better off with one of the Korean 40" displays like the Wasabi Mango with native DisplayPort? It would be a little less than the Samsung TV I'm looking at, with the downside of around a 2 week wait for shipping.

***ToastyX*** · 10-17-2015, 06:23 AM

(10-16-2015 02:21 PM)silent-circuit Wrote: First question is, is there any reason I'd be better off using a straight HDMI cable, from the card's HDMI port to the TV? I figured since the card is HDMI 1.4 and everything I read says you need 2.0 to get 3840x2160 I would be better using the DVI port and the adapter, but maybe I'm wrong there?

6000-series cards don't even support HDMI 1.4. You need HDMI 1.4 to get 3840x2160 @ 30 Hz and HDMI 2.0 to get 3840x2160 @ 60 Hz. 6000-series cards won't do 3840x2160 @ 30 Hz without the pixel clock patch.

HDMI is electrically equivalent to single-link DVI. Using an adapter won't help. The HDMI port might handle higher pixel clocks better than the DVI ports.

(10-16-2015 02:21 PM)silent-circuit Wrote: Is there any way around this limitation? I was under the (apparently mistaken) impression that the pixel clock patch would fix it.

The pixel clock patch allowed you to get 3840x2160 @ 30 Hz. You will not be able to get 3840x2160 @ 60 Hz with 4:4:4 chroma.

It might be possible to get 3840x2160 @ 60 Hz with 4:2:0 subsampling, but I don't know if this works with 6000-series cards. Use CRU to edit a custom extension block. Add a TV resolutions data block, and set the "4:2:0 resolutions" option. Then add 3840x2160 @ 60 Hz in there. Make sure to add an HDMI support data block as well.

(10-16-2015 02:21 PM)silent-circuit Wrote: Will I have to get a new GPU if I go to a 4K display, or do you think it's an issue with this model of TV specifically?

You definitely need a newer GPU to get 3840x2160 @ 60 Hz with HDMI, but I'm not sure if any GPUs support HDMI 2.0 yet.

falkentyne · 10-17-2015, 06:54 AM

(10-17-2015 06:23 AM)ToastyX Wrote:
(10-16-2015 02:21 PM)silent-circuit Wrote: First question is, is there any reason I'd be better off using a straight HDMI cable, from the card's HDMI port to the TV? I figured since the card is HDMI 1.4 and everything I read says you need 2.0 to get 3840x2160 I would be better using the DVI port and the adapter, but maybe I'm wrong there?
6000-series cards don't even support HDMI 1.4. You need HDMI 1.4 to get 3840x2160 @ 30 Hz and HDMI 2.0 to get 3840x2160 @ 60 Hz. 6000-series cards won't do 3840x2160 @ 30 Hz without the pixel clock patch.

HDMI is electrically equivalent to single-link DVI. Using an adapter won't help. The HDMI port might handle higher pixel clocks better than the DVI ports.

(10-16-2015 02:21 PM)silent-circuit Wrote: Is there any way around this limitation? I was under the (apparently mistaken) impression that the pixel clock patch would fix it.
The pixel clock patch allowed you to get 3840x2160 @ 30 Hz. You will not be able to get 3840x2160 @ 60 Hz with 4:4:4 chroma.

It might be possible to get 3840x2160 @ 60 Hz with 4:2:0 subsampling, but I don't know if this works with 6000-series cards. Use CRU to edit a custom extension block. Add a TV resolutions data block, and set the "4:2:0 resolutions" option. Then add 3840x2160 @ 60 Hz in there. Make sure to add an HDMI support data block as well.

(10-16-2015 02:21 PM)silent-circuit Wrote: Will I have to get a new GPU if I go to a 4K display, or do you think it's an issue with this model of TV specifically?
You definitely need a newer GPU to get 3840x2160 @ 60 Hz with HDMI, but I'm not sure if any GPUs support HDMI 2.0 yet.

The Titan-X ($$$) does.
Apparently the GTX 980 does also
http://www.geforce.com/hardware/desktop-...ifications

silent-circuit · (Last edited: 10-21-2015, 05:05 PM by silent-circuit)

First up, thank you both for your help -- ToastyX you do great work.

Yes, the Nvidia Geforce 970/980/980ti/Titan X all support HDMI 2.0.

At this point no AMD cards (including the Fury/Fury X/Fury Nano) support HDMI 2.0 -- instead AMD keeps claiming that DP 1.2a to HDMI 2.0 active adapters that will support 4K@60Hz are "right around the corner" so it "doesn't matter" but this is a problem because:
1. these adapters aren't available yet (current DP 1.2 to HDMI adapters top out at 4K@30Hz from what I can tell)
2. these adapters cost extra when the Fury series is already the same price as the 980ti or more, but doesn't out-perform it in most cases.

Thankfully I'm not a GPU fanboy and will likely be switching back to Nvidia this generation for that reason. AMD's GPU division appears to be digging its own grave lately.

I'll play around with the lower chroma 60Hz thing today, but this display is likely being returned before the end of the week to be replaced with either:

1. 40" Phillips (VA panel) for $800
http://www.bestbuy.com/site/philips-40-i...Id=6228127

2. 40" Samsung for $700-$1100 depending on the model, 6400/6500 or 7100
http://www.bestbuy.com/site/samsung-40-c...Id=3953157

3. 32" BenQ (IPS) for $950 (really more than I want to spend, especially for the size, but figured I should include a "proper" monitor in the list)
http://www.bestbuy.com/site/benq-32-ips-...Id=4058193

4. 40" Wasabi Mango AH-IPS (LG panel) Korean-built Ebay special for ~$700

All but the Samsung have Displayport 1.2, so that's a tick against the Samsung -- it is HDMI 2.0 only. The up-sides of the Samsung are that it has better contrast in "movie" mode (I don't own a TV so would use this panel for watching movies in addition to PC stuff) and it's available locally. The other displays I'd be waiting a week or more on shipping. The Samsung also has the advantage of better over-all quality control than BenQ from what I've read, and the fact that I could go exchange it easily if I did get one with bad light bleed or uniformity issues. I'm still trying to figure out exactly what all is different between the Samsung 40" 6400/6500/7100 models to warrant the $300 or so price difference, and will be asking about that on AVSforum and elsewhere. The Phillips gets fairly good reviews and isn't the /most/ expensive, and I did like the last VA panel I had for blacks, but ghosting and response time was a problem and I'm really spoiled by the current Planar PX2611w 26" 1920x1200 IPS display in that respect -- almost no input lag and fairly good response time, very little ghosting.

Still don't know what to do.

EDIT: Don't know if it's me doing something wrong or a compatibility issue, but I've had no luck getting 60Hz at 4K with 4:2:0 Chroma after messing around with CRU for a bit.