Some questions about eyefinity

[Novae]

Hi all,

A bit of background to begin, i currently run 2 LG W2252(1680x1050) 22" LCDs via twin-view on a 7600GT. I'm looking at upgrading my PC specifically upgrading to a ATI 6xxx card to take advantage of triple-head(I will be also purchasing another LG LCD). For software i'm running a gentoo ~amd64 system with xfce 4.7.

I like the way twin-view works, it allows me to have a spaned display for my desktop and lets my WM know where the monitor borders are. It also allows me to turn off one of the monitors(selectively via meta-modes like 1680x1050, NULL or NULL, 1680x1050) if i need to run a game or other full screen application on just one monitor. Generally i do this in a separate X session while keeping my spaned desktop session running.

Is eyefinity a similar technology to twin-view? Can i selectively turn monitors off to run just a single monitor for something like xbmc to run on the central screen? (An after thought was that i could possibly just use a second x configuration file that only turns on the center monitor as i almost always load xbmc into its own X session, this is messy however and i'd prefer the option to control it via xrandr or similar. even if i could just change from 5040x1050(l+c+r) to 3360x1050(l+c) to 1680x1050(c) and then smaller 4:3 resolutions on the center monitor via xrandr i'd be happy)

I assume eyefinity allows full 3d acceleration across the whole span? So i can run ultrawide games in wine?

Does eyefinity like twin-view let x know that it is creating a span, so that x is able to inform the WM where things like monitor borders are?

Cheers,
Novae

[BlackStar]

I recently swapped my Nvidia 9500GT for an Ati 4850 on my Linux workstation. To answer your questions: yes, eyefinity does what you want.

In fact, it is superior to TwinView in most ways:
- it supports xrandr and randr 1.3.
- it reports correct refresh rates (Nvidia reports random rates)
- it allows you to rotate one or more monitors into portrait mode, keeping the rest in landscape. Nvidia simply cannot do this.
- it hotplugs new monitors as soon as you connect them. I've never managed to get Nvidia to detect a new monitor without running nvidia-config.

I am seriously impressed! Ati's drivers have improved massively those past 12 months. VDPAU be damned, this is the first time I am actually happy with the state of graphics on Linux.

Looking forward to the 11.1 drivers and the vsync fix.

[rohcQaH]

"Eyefinity" is two things:
* the hardware's capability of more than 2 outputs
* some windows driver tweaks making such setups easier. Funny enough, the capabilities added were present on linux for.. decades?

There's no special linux software for eyefinity, you use xrandr as usual. Yes, proper xrandr is superior to those twinview-hacks. Triple portrait setup <3


Oh, don't forget that only two DVI/HDMI-connections are supported. For the third monitor, you'll have to use DisplayPort (or an active (!) DP->DVI adapter).

[chithanh]

What you could do is test your desired setup with a cheap eyefinity card, like this one and buy the more expensive 6xxx card only when eyefinity does what you want.

[Novae]

Thanks for the help guys, i think you've definitely convinced me to move across to an ATI card. Now i just have to source another monitor. I was originally going to source a third identical LCD however it seems they have become somewhat of a rarity on the market. Not necessarily in term of eyefinity but just in term of general useability how does running multiple resolutions go? Say for example the central screen running 1920x1080 or 1920x1200 and the side's only running at 1680x1050? Would still probably invest in a third 22" so physical panel size would be the same.

Cheers.
Novae.

[Novae]

A couple of additional things while i'm here.

1. I know wine's predominant focus is at getting things to work on the nvidia drivers at this point in time, but has anyone found this to be an issue. I generally play EVE Online and a small amount of WoW plus a bunch of older(early mid 2000's) games.

2. If i purchased a 1920x1080 22" LCD would running it at 1920x1050 cause any noticeable distortion, this way i wouldn't have to deal with the slight disparity between pixel sizes in multi-monitor gaming and the like.

[rohcQaH]

Different monitor sizes / resolutions should not be a problem for a desktop environment (but I haven't tested xfce). Spanning a game across three monitors with different resolutions has it's problems though: something will get cut off. The windows drivers don't do multiscreen spans unless all monitors use the same resolution.

Avoid running monitors at non-native resolution. That's acceptable for movies and games, but not if you like text to be easy to read.

I'd go for another monitor with the same pixel size (0.282 mm), otherwise objects may magically become larger or smaller when they cross screen boundaries.


Can't tell you much about fglrx+wine except to try appdb.winehq.org for fglrx-specific hints. I've had major trouble with guildwars (system crashes after an hour of gaming), but that was a year ago. Everything else I used wine for worked fine.

[rohcQaH]

Oh, one more thing: windows games and/or wine are usually unaware of multiscreen setups - they use an ancient X extension for commands like "set resolution to x*y", which doesn't translate to multiple monitors at all.
It worked with nvidia because TwinView basically fakes a multiscreen setup as a single screen resolution.

With xrandr, you'll need some workarounds - worst case, an init script that sets up xrandr as desired, then launches the game in windowed mode with a huge, borderless window. Sometimes it's enough to set the correct resolution to some .ini - the modesetting call will fail (there's no fitting single screen resolution) but the game will continue anyway.

[frank]

eyefinity does what you want.

In fact, it is superior to TwinView in most ways:
- it supports xrandr and randr 1.3.
- it reports correct refresh rates (Nvidia reports random rates)
- it allows you to rotate one or more monitors into portrait mode, keeping the rest in landscape. Nvidia simply cannot do this.

Nvidia can, my setup is 2560x1440 landscape plus 1200x1600 portrait on a 8800 GT.
Works fine BUT:

This setup is dog slow (compared to NOT running a monitor in portrait mode or Windows 7). It seems like rendering on the 90° rotated screen is completely un-accelerated.

Will this setup work better using a 5770 or 6850?
Which driver do I need ? Proprietary, open source or open source WIP (git)?
(a third monitor, 1920x1200 landscape, will be connected also)

Is there any way that compiz/KDE4 is supported?

Frank

[pwyll]

Nvidia can, my setup is 2560x1440 landscape plus 1200x1600 portrait on a 8800 GT.
Works fine BUT:

This setup is dog slow (compared to NOT running a monitor in portrait mode or Windows 7). It seems like rendering on the 90° rotated screen is completely un-accelerated.

Will this setup work better using a 5770 or 6850?
Which driver do I need ? Proprietary, open source or open source WIP (git)?
(a third monitor, 1920x1200 landscape, will be connected also)

Is there any way that compiz/KDE4 is supported?

Frank

With multiple monitors, the width of the desktop is the sum of the widths of the various monitor resolutions while the height is the largest height among your various monitors resolution.

In most cases, rotating one monitor to portrait causes the desktop size to increase.
This increase in desktop size is what leads to the slow down that you experienced.

With multiple monitors and the larger desktop sizes they have you will get better performance with cards that have larger RAM. With the setup you are planning on getting I would recommend a card with 2Gb.

I'd go with the 6850 rather than the 5770. Or even better still get a 6950 2GB if its within your budget.

For best performance with any recent ATI card the proprietary driver is what you want.

My setup is two 1440x900 and one 1920x1080 in portrait mode running on a 6970 (this was originally a 6950 that I upgraded via a bios mod). KDE 4.5 works fine.

Hope this helps.