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Desktop compositing latency is real

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141–150 of 306 posts

Re: Desktop compositing latency is real

#141
post #99
post #23

This is also why picking a good monitor is important for software development. Some monitors have tons of input lag (60-70ms) and that's the time it takes for you to see what you're typing to reach the display. This also includes the time it takes to see you move your mouse cursor too. I did a huge write up on picking a good monitor for development which can be found at: https://nickjanetakis.com/blog/how-to-pick-a-g…

That's an affiliate link fwiw

Why do people care about affiliate links? Serious question.

Re: Desktop compositing latency is real

#142
post #29

Earlier quoted context omitted.

I have the same monitor and it's pretty good. The only thing I don't quite like is the pixel size, it's a bit small for native scaling. I kind of wish i had gone for the 27". I went with two 25" because two 27" were a bit too big for me.

P2715Q user here. One of the best monitors currently available, excellent color reproduction, top of the line quality. The 4K resolution however is a major problem when you are using Windows 7. Some applications will not play correctly when you try to scale up and at the end you get a mess. Windows 10 is better, but not perfect.

Have the same monitor, it's my third Dell monitor since I bought my 2405fpw back in 2005. I've always gotten excellent performance from them and the 2405 lasted 12 years.

The 4k resolution and scaling can cause issues with some apps as you noted. This is especially true if you use multiple panels with heterogeneous resolutions, connect with displayport and occasionally turn one monitor off. This causes windows to move everything to the other display which is a mess. However after futzing with it for a few days post-purchase I had it all working well enough to deal with, even though I occasionally get slack in an over-maxed window on the smaller display. Btw this program is really useful for smoothing mouse movement between the larger and smaller displays in windows 10: https://github.com/mgth/LittleBigMouse

Re: Desktop compositing latency is real

#143
post #23

This is also why picking a good monitor is important for software development. Some monitors have tons of input lag (60-70ms) and that's the time it takes for you to see what you're typing to reach the display. This also includes the time it takes to see you move your mouse cursor too. I did a huge write up on picking a good monitor for development which can be found at: https://nickjanetakis.com/blog/how-to-pick-a-g…

Indeed. I would rather take an excellent monitor, keyboard and mouse over a faster machine without them. Sadly this means I am pretty much limited to desktops as finding a laptop with a colour accurate 120Hz+ display with excellent keyboard seems to be impossible unless I look at some gaming laptop monstrosity that weights 5KG and has a 1 hour battery life. If anyone reading this know of a good laptop for development please let me know!

Re: Desktop compositing latency is real

#144
> ads in the start menu

I turned off windows update quite a while ago and was considering updating my system recently until now.

I'm on version 1703

Build: 15063.138

Why would I ever update now?

Re: Desktop compositing latency is real

#145
post #80

Earlier quoted context omitted.

P2715Q user here. One of the best monitors currently available, excellent color reproduction, top of the line quality. The 4K resolution however is a major problem when you are using Windows 7. Some applications will not play correctly when you try to scale up and at the end you get a mess. Windows 10 is better, but not perfect.

I looked at 4k monitors but ultimately decided against it because as soon as you start scaling then you lose the extra screen real estate. At 4k 150% scaling you end up with the same screen space as 2560x1440.

I personally like the higher resolution that scaling provides, but if you don't mind low DPI you should check out the 42.5" 4k panel that Dell makes[0]. I have one in my home office, and while it's not great for design and photo editing, the sheer real-estate available is mind blowing.

[0] http://www.dell.com/en-us/work/shop/dell-43-ultra-hd-4k-mult...

Re: Desktop compositing latency is real

#146
post #80

Earlier quoted context omitted.

P2715Q user here. One of the best monitors currently available, excellent color reproduction, top of the line quality. The 4K resolution however is a major problem when you are using Windows 7. Some applications will not play correctly when you try to scale up and at the end you get a mess. Windows 10 is better, but not perfect.

I looked at 4k monitors but ultimately decided against it because as soon as you start scaling then you lose the extra screen real estate. At 4k 150% scaling you end up with the same screen space as 2560x1440.

I agree and I _almost_ didn't buy the 4k panel, but as I noted in my comment above my first Dell panel lasted 12 years, and that's a long time.

Re: Desktop compositing latency is real

#147
post #99

Earlier quoted context omitted.

That's an affiliate link fwiw

Why do people care about affiliate links? Serious question.

It's good to know that the person posting the link has a financial stake in it. Depending on the context this can mean a lot - like a review or recommendation.

Re: Desktop compositing latency is real

#148

Earlier quoted context omitted.

ethernet over multimode fiber, I want to be able to have accessories hundreds of meters away from my computer

Careful, multi-mode fiber is near its scaling limits. 10GBASE-SR and 25GBASE-SR exist, but that's about it. (By contrast, 40GBASE-LR and 100GBASE-LR work over single-mode fiber, and DWDM + coherent optics can push the medium much further.) Wouldn't want to be stuck at 25 gbps forever ;-)

Yeah, some of us can type pretty fast. And for mice, some of us take clicker games seriously.

Re: Desktop compositing latency is real

#149
post #94
post #37

Earlier quoted context omitted.

Layers of abstraction take you further away from the metal. The more layers of abstraction your keypress must traverse before rendering is complete and the photons have reached your retina, the longer it will be until that happens. Layers of abstraction make complex tasks more reachable by a larger number of programmers by reducing the amount of specialist knowledge about those lower layers required to do the job. Th…

Layers of abstraction make complex tasks more reachable by a larger number of programmers by reducing the amount of specialist knowledge about those lower layers required to do the job. The more layers of abstraction you have, the less they have to worry about lower levels and can just get on with what they want to do. Sometimes this is certainly true, but I think when it comes to abstraction layers, people tend to o…

Absolutely, the amount of technologies often required for full stack web development is astounding. Even for a smallish website, you can be quickly staring at 30+ essential pieces of technology you need to at least understand somewhat. Several languages, package managers, IDEs, frameworks, a database, debuggers, compilers, project management tools, virtual machines, server software, your OS, supporting protocols (SSL, TCP/IP, SSH, DNS etc.) and the list goes on. Who can truly understand all of that simultaneously? All of that bloat just massively increases the chance of errors and inefficiencies.

Re: Desktop compositing latency is real

#150
post #19

I recently measured it with my phone's camera in slow motion mode. The system is an AMD Ryzen 1800X with AMD R9 280x GPU, KDE Plasma with KWin window manager in compositing mode. Key press to screen output latency was ~33 millseconds (90 fps recording, so increments of 11) in KWrite. The computer feels plenty responsive with that latency, and I hate latency... It is a full stack real world result - for comparison pur…

How are you measuring from key activation?

I don't - just filmed keyboard and screen together; key down is easy to see. I have a quality keyboard (Fujitsu KBPC PX eco) connected by PS/2, and as stated above I'd expect little extra latency from USB. As measured, anyway, there is no space for significant keyboard lag in the result. The reason why I measured latency was that I seemed to notice a change after changing GPU driver kernel options. End to end was easiest to measure. The result was close to the theoretical minimum so I stopped there.
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