| From: Erich Welz via talk <talk@gtalug.org> | Most DVI cables (single link) max out at 1920x1200. | | Older versions of the HDMI spec didn't support above 1920x1200, so that | could also be suspect. | | My guess is the only way to get 2560x1600 out of that monitor is via | DisplayPort or dual-link DVI cable Yes. According to <http://www.dell.com/ed/business/p/dell-u3011/pd> the monitor has DisplayPort, audio connectors (supports 5.1 channel audio connection), two HDMI 1.3 and two DVI-D connectors with High-Bandwidth Digital Copy Protection (HDCP). So the right way of connecting to a T450 should be DisplayPort to DisplayPort. A distant second-best way would be an active DisplayPort to dual-link DVI thingee. Those are about $100 (although I've scrounged them on Kijiji for $20). (I have an even older Dell UltraSharp 3007 which only has dual link DVI.) I don't think that a simple DisplayPort to HDMI cable or dongle can support more than 1920x1200@60Hz. I could be wrong. But Michael's experience supports this. A DP cable should be cheap and easy to acquire. <https://www.primecables.ca/c-1049-displayport-cables> (Free shipping on first order over $10) <http://www.canadacomputers.com/index.php?cPath=1340_1440_748> BONUS If you want to be neo-retro, you can buy an audio amplifier with tubes AND bluetooth, triggering free shipping, from primecables. <http://forums.redflagdeals.com/primecablescom-25w-stereo-tube-hybrid-amplifier-usb-bluetooth-115-free-ship-2176890/>

| From: Michael Hill via talk <talk@gtalug.org> | So I shouldn't be surprised that I get 3840x2160@30Hz on the newer | monitor at work | <http://www.dell.com/ed/business/p/dell-p2815q-monitor/pd> | | 1 DisplayPort | 1 Mini DisplayPort | 1 HDMI (MHL) | 1 DisplayPort out (MST) | | with the HDMI cable and mini DisplayPort adapter. I don't completely understand why 3840x2160@30Hz works on pre 1.4 HDMI. But it does, at least in some cases. That's what I use on my desktop. You should get a DP to DP cable for work and then you should have 3840x2160@60Hz. Of course I cannot be sure since I haven't tried any of this. I cannot do that on my desktop because my monitor is really an early UltraHD TV and only has HDMI 1.3 (?) connectors. It cannot be driven 3840x2160@60Hz. I wish it could, but the experience isn't as bad as I would have guessed. There are other subtle things that more bandwidth should allow. My monitor does 4:2:2 chroma subsampling and your monitor doesn't (at least when using DisplayPort). Again, the results are usually not a problem for me, but not having subsampling is better. The next improvement will be HDR, requiring more bits of colour per pixel. Neither your systems nor mine support that.

On 2018-03-10 12:02 PM, D. Hugh Redelmeier via talk wrote:

BONUS

If you want to be neo-retro, you can buy an audio amplifier with tubes AND bluetooth …

In the everything-old-is-new-again department, Korg recently announced a triode thermionic valve amplifier in a DIP package: the Nutube <http://korgnutube.com/en/>. This is a commercialization of an idea that's been kicking around amateur radio for a few years: using a vacuum fluorescent display (VFD) as an amplifier¹. Sometimes it's nice to hear about a chip that doesn't have vulnerabilities built-in. So saying, knowing VFDs sensitivity to magnetic fields it might be fun to extend my pleasantly futile research into artisanal hardware random number generation with a Nutube. Tube-based random number generators were proposed by Turing for the ACE (1945-46) and later used in RAND's "Million Random Digits" (1949) <https://www.rand.org/pubs/monograph_reports/MR1418.html> and in ERNIE (1957), the UK Premium Bond computer. cheers, Stewart ¹: this is the oldest ref I could find, from 2005: <https://www.electronicspoint.com/threads/vfd-as-an-audio-rf-amplifier.29314/>

On Mon, Mar 12, 2018 at 10:59 AM, Lennart Sorensen <lsorense@csclub.uwaterloo.ca> wrote:

Passive displayport to hdmi or DVI adapters are only single link, and to use DVI to get 2560x1600@60Hz requires DVI dual link.

As you have found out, native displayport on the other hand works.

Another option with be an active displayport to dual link DVI adapter.

Also the HDMI is single link on the monitor so no adapter could ever make the monitor do more than 1920x1200@60Hz using HDMI input on the monitor. The HDMI input on that monitor only existed to allow connecting a bluray player or other similar device at 1920x1080. It was not for computer use.

Good to know. If I add a ThinkPad docking station, will anything stop me from running *two* monitors at resolutions higher than 1920x1200? Mike <div id="DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2"><br /> <table style="border-top: 1px solid #D3D4DE;"> <tr> <td style="width: 55px; padding-top: 13px;"><a href="http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail" target="_blank"><img src="https://ipmcdn.avast.com/images/icons/icon-envelope-tick-green-avg-v1.png" alt="" width="46" height="29" style="width: 46px; height: 29px;" /></a></td> <td style="width: 470px; padding-top: 12px; color: #41424e; font-size: 13px; font-family: Arial, Helvetica, sans-serif; line-height: 18px;">Virus-free. <a href="http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail" target="_blank" style="color: #4453ea;">www.avg.com</a> </td> </tr> </table><a href="#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2" width="1" height="1"></a></div>

On Mon, Mar 12, 2018 at 03:23:56PM -0400, Michael Hill via talk wrote:

Good to know. If I add a ThinkPad docking station, will anything stop me from running *two* monitors at resolutions higher than 1920x1200?

If the laptop is reasonably new it should handle 3 or 4 displays and should handle even 4k displays. So with a docking station you should be able to run at least a couple of high resolution external displays using displayport or dual link DVI. With newer models and displayport, you can even daisychain a pair of 2560x1600 displays on one displayport (as long as the screens and system are all displayport 1.2 compatible), or 3 1920x1200 screens. The real limit is usually that intel only allows a total of 3 displays and nvidia usually only allows 4 in total for a system. I think AMD has allowed 6 in some cases. So a single displayport output on a laptop could go to 2 or 3 decent monitors without a docking station being required. Now how well linux supports this yet I don't know. Displayport MST support is pretty new. -- Len Sorensen