T420s Optimus quad digital monitor output problem

[DiamondJoeQuimby]

I purchased a Thinkpad T420s with Optimus graphics along with a Mini Dock Plus Series 3 (4338-10U) to replace my triple monitor desktop setup. So far I’ve been unable to replicate Lenovo’s quad digital monitor setup described in the following documentation:

NVIDIA Optimus - ThinkPad Multiple Monitor Configurations

Technical Brief - Thinkpad Multiple Monitor Configurations Using nVidia OPTIMUS Technology

I’m trying to connect three Dell U2410’s (1920x1200) in the following fashion:

• Thinkpad Display (1600x900)
• Monitor 1 – DisplayPort (Thinkpad T420s) (1920x1200)
• Monitor 2 – DVI1/DP1 (Dock) (1920x1200)
• Monitor 3 – DVI2/DP2 (Dock) (1920x1200)

According to the documentation above, this configuration should work. The problem I’m running into is the nVidia NVS 4200 controls all the digital outputs (DVI & Displayport) and will only allow two displays. The Intel IGP controls the T420s display and the VGA outputs. I am able to get the setup running using the VGA output in place of the DVI output on the dock, but this is not an optimal solution.



According to the latest Readme.txt for the Optimus drivers:

NVIDIA Optimus Technology

…

DISPLAY TOPOLOGY

Since Optimus Technology has the ability to use two display adapters, some
display monitors (or displays) are assigned to specific adapter. Below
describes which display adapter controls the display connector for a certain
display monitor.

ThinkPad T420, T420i, T420s, T420si, T520, T520i
NVIDIA NVS 4200M
- Computer's DisplayPort connector
- Docking Station's DVI connector(s) or DisplayPort connector(s)

Intel HD Graphics Family
- (Computer's LCD)
- Computer's analog VGA connector
- Docking Station's analog VGA connector

So if the nVidia NVS 4200M controls all the digital outputs on the Thinkpad and dock, but only supports two displays, how can one use a quad display setup as described in Lenovo’s documentation?

So far I have been unable to get an answer from Lenovo Tech Support, which I have spent more time educating them on what their product should be capable of.

Latest BIOS (1.30)
Latest Optimus Drivers (8.17.12.7593)

Any help would be greatly appreciated.

[rjoffe]

I have contacted Lenovo, about this same problem. I received a response today

In short the documentation is wrong, and will be updated soon.

Max is 2 DVI/DP and one VGA.

Ron

[bapatterson]

I have been watching this thread for further comments, but there have been none.

I just find it so unlikely that three external digital monitors cannot be run concurrently since that would be contrary to very clear information from Lenovo, which to date has not been updated.

What exactly did Lenovo say in their e-mail to you on the subject?

[rjoffe]

Let me contact the folks with whom I conversed with, and get their permission to post the entire email thread.

Give me a few days.

Ron

[bapatterson]

According to http://download.lenovo.com/ibmdl/pub/pc ... un2011.pdf listed by the original poster, the system should be able to handle quad as follows:

ThinkPad display
Internal DisplayPort
Dock DisplayPort #1
Dock Digital Video #2

[rjoffe]

Entire thread: ( I removed email addresses to prevent scavenging )

--------------------------------------

Subject: Re: PSREF Version 409 Available
From: Ron Joffe
To: Zhang Xiaozhen

Hi,

I was wondering if you could direct me to a technical resource who can
assist me with configuring the quad monitor solution as outlined in :

http://support.lenovo.com/en_US/detail. ... MIGR-76617

http://download.lenovo.com/ibmdl/pub/pc ... iple_moni=
tor_config_nvidiaoptimus_jun2011.pdf

The same information is found in the section labeled "Multiple Monitor Con=
=EF=AC=81
gurations with Mini Dock Plus Series 3" in the latest psref document.

Thanks,

Ron

--------------------------------------

To: ron joffe
Subject: Quad Multiple Monitors - ThinkPad systems
From: Gary Carlson

Hello Ron,

Thank you for your email to the PSREF team.

In April, May 2011, I worked with the ThinkPad marketing team (Don Cox) to
create some of the multiple monitor documents.

I would like to offer some assistance. However, I am not a Field Technical
Sales Specialist (FTSS).

If possible, can you provide more information?

I hope that Don Cox and I are able to assist.

Again, thank you for your email.

Regards,

Gary Carlson
WW Options Marketing

--------------------------------------

Subject: Re: Quad Multiple Monitors - ThinkPad systems
From: Ron Joffe
To: Gary Carlson
Hi,

Thanks for the reply.

Based on the literature, I recently purchased a T420 (4170-CTO S/N
R9K864K), and a Mini Dock Plus Series 3 (4338-30U).

It is running Win7 Pro as supplied.

I am attempting to utilize 3 20" LCD's (1600x1200) plus the onboard LCD dis=
play.

=95 Thinkpad Display (1600x900)
=95 Monitor 1 =96 DisplayPort (Thinkpad T420s) (1600x1200)
=95 Monitor 2 =96 DVI1 (Dock) (1600x1200)
=95 Monitor 3 =96 DVI2 (Dock) (1600x1200)

In attempting to utilize both the Win7 display properties or the
nVidia NVS 4200M control window, I am unable to get the configuration
to allow all three digital outputs plus the on board LCD.

The closest I have been able is the following:

=95 Monitor 1 =96 VGA (Dock) (1600x1200)
=95 Monitor 2 =96 DVI1 (Dock) (1600x1200)
=95 Monitor 3 =96 DVI2 (Dock) (1600x1200)

Let me know what other details I can provide. I bit of google
searching also showed others experiencing the same issue.

Thanks,

Ron
--------------------------------------


To: Ron Joffe
Subject: Fw: Quad Multiple Monitors - ThinkPad systems
From: Gary Carlson

Hello Ron,

Thank you for your quick reply and added information.

It was very helpful.

After receiving your email, Don Cox (ThinkPad marketing team) and I met.
Don and I reviewed your email, and compared to the various quad monitor=20
documents.

Don is planning to re-test, and verify the various configurations on=20
Wednesday and Thursday.=20

Don is also planning to review test results with the ThinkPad product=20
engineering team.

Please allow the ThinkPad team another 1-2 days.

We apologize for this issue and hope to quickly resolve.

I hope this update is helpful.

Again, thank you.


Regards,

Gary Carlson
WW Options Marketing

--------------------------------------

To: Ron Joffe
Subject: Re: Fw: Quad Multiple Monitors - ThinkPad systems
From: Don Cox

Mr. Joffe,

I have obtained the necessary equipment and re-tested your configuration to validate what you are seeing. My results (as well as Lenovo Help Center confirmation) show basically the same results as you have laid out in your e-mail. Up to 4 different displays can be viewed simultaneously including 2 digital outputs (DisplayPort and/or DVI-D) with the other display outputs being the ThinkPad monitor and the VGA (analog) port on the Mini Dock Plus. The VGA port on the dock allows resolution up to 2048 x 1536. So, with your configuration of 2 DVI-D monitors and a DisplayPort monitor plus the Mini Dock Plus, you can plug either the DisplayPort monitor into the VGA port of the Dock or one of the DVI-D displays into the VGA port of the Dock to obtain 4 simultaneous displays.

Below is a table depicting what we plan to show as supported ThinkPad T420s, T420, and T520 discrete graphics system / Mini Dock Plus quad monitor configurations. Corrections will be made shortly to our current literature on this topic. Thank -you for your comments!



Don Cox
Program Manager
ThinkPad Business Unit

[bapatterson]

Thanks rjoffe.

Wow. That is a pretty substantial variance from what Lenovo previously published.

I'm not very happy about it (since I have already purchased two "Plus" docks and am just waiting until the T520 replacement is announced to decide if to go with the 520 or its successor).

Was planning to use a Dell U2710 as my central monitor flanked by U2410s on both sides. How big of an image hit am I going to have on one of the 2410s using VGA?

[rjoffe]

How big of an image hit am I going to have on one of the 2410s using VGA?

I am currently running a 20" at 1600x1200 using VGA and two using DVI. I see no difference between the two. On a set of older 20" LCD's I see significant difference between analog and digital.

[Bashar]

sorry for bringing an old topic but based on the image
i'm supposed to be able to drive also the W520 using two DVI ports and VGA ?

because i spent complete day today without a success to bring 3 external monitors (1 VGA X 2 DVIs) to work on ubuntu linux and on windows 7 i have same what shows above "This GPU supports up to 2 displays" which means thinkpad LCD and two monitors which worked just fine

the monitors i'm trying with are thinkvision L220x, and two 19" older thinkvisions (IBM and Lenovo) the 3 monitors have DVI and VGA ports, no matter what combinations i did using all dock ports or two dock DVI ports and laptop's VGA ports wasn't able to make 3 external to work.

I don't need the thinkpad LCD to work but if it does that would be even better

Thanks

[aden045]

I just find it so unlikely that three external digital monitors cannot be run concurrently since that would be contrary to very clear information from Lenovo, which to date has not been updated.

What exactly did Lenovo say in their e-mail to you on the subject???