Displayport: A Better Video Interface • Hacker News Board

Re: Displayport: A Better Video Interface

#391

Post by smachiz » Wed, Jul 12, 2023, 4:35 PM UTC

muhammadusman wrote: post #172

smachiz wrote: post #60

Earlier quoted context omitted.

It might be your dock. Check to see whether it's USB or Thunderbolt. Thunderbolt docks are more expensive, but considerably more efficient and faster than USB (assuming your laptop/device supports Thunderbolt). Thunderbolt docks are basically PCIe extension devices, whereas USB docks attach everything as USB, with all the common challenges USB has on systems (like dropped audio when the CPU is busy).

Thanks for the info. The dock is the CalDigit TS3 Plus dock and I’m using it with an LG monitor. Their page says it’s a Thunderbolt dock so I wonder if there’s anything else about this particular dock that could be causing this issue. Btw when the monitor was connected over HDMI, it was fine playing audio. https://www.caldigit.com/ts3-plus/

That's pretty interesting. Might be worth trying a new displayport cable, or checking whether there's a firmware update for either the dock or monitor.

Re: Displayport: A Better Video Interface

#392

Post by aidenn0 » Wed, Jul 12, 2023, 5:59 PM UTC

bleepblop wrote: post #349

aidenn0 wrote: post #294

Earlier quoted context omitted.

Besides the DTS passthrough (which works just fine), it supports 48kHz PCM from my media-center, so I don't know what more is needed.

Again, that is fine. Besides getting an uncompressed 2 channel signal; anything above 2 channels is going to be compressed and frequencies carved out of the additional channels due to the encoding process. Thus a loss of fidelity. You "may" get a multi channel signal, but it is not 1:1. There are plenty of papers written about the subject since it's nearly a 50 year old technology.

My laptop definitely supports up to 8 channels (7.1) of uncompressed PCM over HDMI. I've tested my receiver up to 5.1 (I don't have an 8-speaker setup) and it works.

[edit]

I have an Intel IGP; Intel has supported this since the G45 (Core 2 Duo era), AMD added it in the HD 4800 era, and nVidia in the GeForce 8300 era. Support for this is over a decade old at this point.

The "stereo only uncompressed" is a S/PDIF legacy, and while HDMI does support S/PDIF, it was already "the bad old way" when Bluray players came out (though it took a few years for discrete GPU makers to catch up).

Re: Displayport: A Better Video Interface

#393

Post by tracker1 » Wed, Jul 12, 2023, 5:59 PM UTC

kaashif wrote: post #371

loup-vaillant wrote: post #347

Earlier quoted context omitted.

Sounds nice, but computer based voting systems, no matter how secure, clean or simple, are fundamentally opaque to the average citizen. That alone undermines the very democracy it tries to support. Paper based voting systems may be bloody tedious but they’re simple, and anyone can participate. As a programmer myself, I have to say no to electronic voting systems. We need to keep it low tech.

Also, they may be opaque even to software engineers, it's not like we have magic powers to look at a physical computer and know what code is running. Even if the code is released: (1) Who can read and understand tens or hundreds of thousands of lines of probably not very comprehensible code? Not many people can and even fewer will. (2) Is the code running on the machines the same as the published code? I don't even k…

Even if you work in the space as a software developer, the shear amount of variance in government voting systems from registration, petition verification/validation, and voting itself is really wide. Some states have rules that vary from county to county. Some of these states have lots of counties. Election systems are some of the most byzantine you can imagine.

Disclosure: I used to work for an Election Services company.

Re: Displayport: A Better Video Interface

#394

Post by IIsi50MHz » Wed, Jul 12, 2023, 6:21 PM UTC

timgws wrote: post #297

Our_Benefactors wrote: post #256

Earlier quoted context omitted.

Two thumbs down for connect pro. I ordered their top of the line 4 computer, 2 monitor DisplayPort KVM and it took months to arrive. I could not cycle between inputs using the buttons. They were more like a suggestion to use that signal path; I would constantly need to power cycle the kvm, monitors, or both. I ended up ditching it on eBay at a significant loss for a $30 usb switch and just switch monitor inputs manua…

I had the same issue with this device. I ended up writing some code that you could run on a machine to operate the switching via the RS232 port: https://github.com/timgws/kvm-switch/ Bonus for adding 'glide and switch' functionality, so you can move the mouse to the edge of the screen and it would jump the input to the next display in your layout. It's like a hardware version of Synergy. Very finicky device, but if y…

Neat! I used to use ShareMouse (pay-ware, if you want more than two machines tied together) for this, because setting it up and keeping it working are so easy compared to whatever version of Synergy existed at the time.

Synergy made me manually configure my monitors by dragging little boxes around in a window, would frequently refuse to connect, would spontaneously disconnect, and repeatedly mangled my config such that I had to keep manually configuring it over again.

With ShareMouse, it was "open a copy of it on each machine, slide mouse in direction of next machine, then optionally enable encryption (to prevent other users' instances of ShareMouse from being able to attach)".

Re: Displayport: A Better Video Interface

#395

Post by bick_nyers » Wed, Jul 12, 2023, 7:59 PM UTC

NavinF wrote: post #144

tshaddox wrote: post #123

> However, I’d like to tell you that you probably should pay more attention to DisplayPort – it’s an interface powerful in a way that we haven’t seen before. Lines like that really show just how long it can take for standards to get on the radar of mainstream tech culture. I remember hearing about and being excited about DisplayPort's move to packetized digital video in college in 2008, and seeing the first Macs with…

> impression that it has been well-known and commonplace for hobbyist and enthusiast PCs for well over 10 years It is. For a long time DP was the only standard that could do variable refresh rate. Even today all high end monitors have DP while the cheapest monitors only have HDMI.

I just wish TV manufacturers would start putting Displayport into their TVs.

GPUs nowadays use 3x Displayport and 1x HDMI, which is quite the bottleneck if you want to max out your ports.

As I understand, HDMI Displayport converter cables often do not have the high end features you might want, such as 4k/120Hz HDR, and/or Variable Refresh Rate. Perhaps this has improved in recent months.

Re: Displayport: A Better Video Interface

#396

Post by bick_nyers » Wed, Jul 12, 2023, 8:12 PM UTC

nfriedly wrote: post #25

I'm annoyed nvidia for putting the current generation of HDMI on their recent GPUs, but leaving them with an outdated version of DisplayPort. For a long time, my advice to anyone was to always choose DisplayPort whenever it was an option. But now that has to have the caveat of "if you have a new high-end GPU and a fancy high refresh rate monitor, HDMI might actually be better for your situation"

I think it's all baked into NVIDIA's product strategy of trying to encourage enthusiasts to upgrade every generation. Yes some enthusiasts will upgrade every generation no matter what strategy you implement, but I would say most enthusiasts philosophy is to buy premium products and skip a generation or two. It used to be just raw computational performance that sold GPUs, but now it's all these additional layers and features, GSYNC, RTX, DLSS, Frame Interpolation, and even the ability to interface with a particular display (e.g. 8k/120Hz) are all part of the product, and so can be reserved to "boost" particular generations desirability. I wouldn't be surprised if there aren't any "software" level enhancements to the 5000 series, just their standard performance uplift, an increase in VRAM capacity (5090 topping out at 32GB), and the new Displayport standard, all to promote and focus on 8K/120Hz and 4k/240Hz gaming. They set the stage for it with the motion interpolation tech. in the 4000 series.

Re: Displayport: A Better Video Interface

#397

Post by 111111IIIIIII » Wed, Jul 12, 2023, 8:45 PM UTC

Strom wrote: post #358

111111IIIIIII wrote: post #56

Earlier quoted context omitted.

And only 1 new version HDMI port but 3 old version DP ports. I use a dual display setup but HDR only works on mu displays with HDMI.

The more expensive Gigabyte RTX 3080+ cards had 3x DP 1.4, 2x HDMI 2.1, 1x HDMI 2.0, which was great even if you could only use 4 of them at the same time due to Nvidia limitations. Unfortunately for the 40 series they stopped offering it and now they're the same as stock Nvidia with 3x DP 1.4, 1x HDMI 2.1. Luckily ASUS still offers a bit more with their 4080+ cards - 2x HDMI 2.1, 3x DP 1.4. I personally depend on th…

Yeah, I only want a 4090 myself.

Re: Displayport: A Better Video Interface

#398

Post by bleepblop » Wed, Jul 12, 2023, 8:50 PM UTC

aidenn0 wrote: post #392

bleepblop wrote: post #349

Earlier quoted context omitted.

Again, that is fine. Besides getting an uncompressed 2 channel signal; anything above 2 channels is going to be compressed and frequencies carved out of the additional channels due to the encoding process. Thus a loss of fidelity. You "may" get a multi channel signal, but it is not 1:1. There are plenty of papers written about the subject since it's nearly a 50 year old technology.

My laptop definitely supports up to 8 channels (7.1) of uncompressed PCM over HDMI. I've tested my receiver up to 5.1 (I don't have an 8-speaker setup) and it works. [edit] I have an Intel IGP; Intel has supported this since the G45 (Core 2 Duo era), AMD added it in the HD 4800 era, and nVidia in the GeForce 8300 era. Support for this is over a decade old at this point. The "stereo only uncompressed" is a S/PDIF lega…

Might I suggest reading up on how both DTS and Dolby encode audio then.

Re: Displayport: A Better Video Interface

#399

Post by unstatusthequo » Wed, Jul 12, 2023, 9:40 PM UTC

Good and interesting video to explain the version diffs in spec: https://www.youtube.com/watch?v=Vn2vdQZhs0w&ab_channel=Linus...

And even better, a calculator based on your monitor capabilities that helps you choose: https://linustechtips.com/topic/729232-guide-to-display-cabl...

I ended up with a $15 2.0 10 foot cable from Monoprice. Fit my ultra wide Samsung G9 pixel pushing needs just fine.

Re: Displayport: A Better Video Interface

#400

Post by aidenn0 » Wed, Jul 12, 2023, 9:58 PM UTC

bleepblop wrote: post #398

aidenn0 wrote: post #392

Earlier quoted context omitted.

My laptop definitely supports up to 8 channels (7.1) of uncompressed PCM over HDMI. I've tested my receiver up to 5.1 (I don't have an 8-speaker setup) and it works. [edit] I have an Intel IGP; Intel has supported this since the G45 (Core 2 Duo era), AMD added it in the HD 4800 era, and nVidia in the GeForce 8300 era. Support for this is over a decade old at this point. The "stereo only uncompressed" is a S/PDIF lega…

Might I suggest reading up on how both DTS and Dolby encode audio then.

DTS and Dolby are unrelated to uncompressed LPCM. HDMI 1.0 supports up to 8-channels, up to 192kHz, and up to 24-bits of depth. In practice, my laptop to my receiver can definitely do 24-bit 48kHz PCM at 8 channels, and that's certainly "full fidelity" for most setups.