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Computer latency 1977-2017


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Interesting analysis. If you ever thought your vintage computer was faster than your modern computer, you're in good company. Go read the whole thing at https://danluu.com/input-lag/but I'll snag some key points:

 

I’ve had this nagging feeling that the computers I use today feel slower than the computers I used as a kid. As a rule, I don’t trust this kind of feeling because human perception has been shown to be unreliable in empirical studies, so I carried around a high-speed camera and measured the response latency of devices I’ve run into in the past few months. Here are the results:

 

post-2410-0-46644300-1514319657.png

 

It’s a bit absurd that a modern gaming machine running at 4,000x the speed of an apple 2, with a CPU that has 500,000x as many transistors (with a GPU that has 2,000,000x as many transistors) can maybe manage the same latency as an apple 2 in very carefully coded applications if we have a monitor with nearly 3x the refresh rate. It’s perhaps even more absurd that the default configuration of the powerspec g405, which had the fastest single-threaded performance you could get until October 2017, had more latency from keyboard-to-screen (approximately 3 feet, maybe 10 feet of actual cabling) than sending a packet around the world (16187 mi from NYC to Tokyo to London back to NYC, more due to the cost of running the shortest possible length of fiber).

 

On the bright side, we’re arguably emerging from the latency dark ages and it’s now possible to assemble a computer or buy a tablet with latency that’s in the same range as you could get off-the-shelf in the 70s and 80s. This reminds me a bit of the screen resolution & density dark ages, where CRTs from the 90s offered better resolution and higher pixel density than affordable non-laptop LCDs until relatively recently. 4k displays have now become normal and affordable 8k displays are on the horizon, blowing past anything we saw on consumer CRTs. I don’t know that we’ll see the same kind improvement with respect to latency, but one can hope. There are individual developers improving the experience for people who use certain, very carefully coded, applications, but it’s not clear what force could cause a significant improvement in the default experience most users see.

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https://groups.google.com/forum/m/?fromgroups#!topic/comp.sys.apple2/tGnFO_b8VCk

 

So.. What can be done to combat the trend of having the oprating system do everything? Isn't that what PROGRAMS are for? And how can the end-user fight bloat effectively? Shouldn't the OS just serve as a file manager, launcher, and to connect all the hardware?

 

Please, no suggestions of switching to Linux. It isn't an option for some.

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I've had ideas for an OS, but they've been shot down as "by the time you've implemented everything necessary to work with modern hardware, you've essentially recreated Windows". (I wanted to create a sort of 64-bit OS with limited multitasking - think OS/2 1.0 but for AMD64 instead of 286 - and the ability to transparently emulate legacy hardware to run old MS-DOS games.)

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https://groups.google.com/forum/m/?fromgroups#!topic/comp.sys.apple2/tGnFO_b8VCk

 

So.. What can be done to combat the trend of having the oprating system do everything? Isn't that what PROGRAMS are for? And how can the end-user fight bloat effectively? Shouldn't the OS just serve as a file manager, launcher, and to connect all the hardware?

 

Please, no suggestions of switching to Linux. It isn't an option for some.

I thought the problems is the programs. They are always running in background when they don't need to. A good example is a web browser. It's nice to have multiple tabs but every tab is running all the time eating up cpu time and memory. If I switch to a word processor those browser tabs are still running. Having multiple programs open is nice but, in most cases, there is no reason they have to be actively running. Task switching not multitasking is all that is needed in most cases.
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I've had ideas for an OS, but they've been shot down as "by the time you've implemented everything necessary to work with modern hardware, you've essentially recreated Windows". (I wanted to create a sort of 64-bit OS with limited multitasking - think OS/2 1.0 but for AMD64 instead of 286 - and the ability to transparently emulate legacy hardware to run old MS-DOS games.)

OS/2 1.3 would be the best pre-built multitasking OS to run PC DOS games. It is not 64-bit. But honestly a 64-bit compiled OS would be just a tiny bit slower for running DOS games due to extra mode and task switching. Just because the os is compiled as 64-bit does not mean it runs legacy code faster.

The best OS to use would actually be a custom 32-bit Real Time OS (VXWorks) or Linux kernel build with ONLY the drivers/services needed built into the kernel.

 

The problem with modern OSes (Win, OSX and pre-built Linux) is they have MANY services and features built in the kernel and also MANY services and features loaded at start. The fastest responding computer I have is a 1993 IBM Thinkpad 500 with 12MB of memory! Seriously I have a custom built low latency 2.0.X Linux kernel (no virtural memory) and it boots in about 5 seconds. Linux kernels newer than 2.0.X are significantly larger and more complex to support virtual memory management. Note: Many of these features and services modern OS have almost everyone certainly needs like tcp/ip, dns client etc...

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OS/2 1.3 would be the best pre-built multitasking OS to run PC DOS games. It is not 64-bit. But honestly a 64-bit compiled OS would be just a tiny bit slower for running DOS games due to extra mode and task switching. Just because the os is compiled as 64-bit does not mean it runs legacy code faster.

The best OS to use would actually be a custom 32-bit Real Time OS (VXWorks) or Linux kernel build with ONLY the drivers/services needed built into the kernel.

 

The problem with modern OSes (Win, OSX and pre-built Linux) is they have MANY services and features built in the kernel and also MANY services and features loaded at start. The fastest responding computer I have is a 1993 IBM Thinkpad 500 with 12MB of memory! Seriously I have a custom built low latency 2.0.X Linux kernel (no virtural memory) and it boots in about 5 seconds. Linux kernels newer than 2.0.X are significantly larger and more complex to support virtual memory management. Note: Many of these features and services modern OS have almost everyone certainly needs like tcp/ip, dns client etc...

I would use the approach of loadable modules and drivers, and keep the basic system as clean as possible and resident programs no bigger than necessary, similar to what was done with MS-DOS 2.

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I would use the approach of loadable modules and drivers, and keep the basic system as clean as possible and resident programs no bigger than necessary, similar to what was done with MS-DOS 2.

If you care about latency then loadable modules is not the way to go. For the least latency build everything in the kernel. Ideally if you don't care about security put everything even the user api and all needed drivers and applications in kernel space. Switching in and out of kernel space adds significant latency. Many RTOSes have done this for many decades. Though nowadays with Linux dominating embedded products this generally not done anymore in the name of security and well latency is generally not a concern anymore. BTW about two to three decades ago I worked on development of embedded solutions for printers, thin clients, set top boxes, PDAs and early tablets etc..

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