Client vs. server/single machine CPU usage

[ahaka]

Hello,

I am testing an old mini-laptop hooked up to an iPad using USB cable to make the iPad work as a touchscreen for PSX CDU unit. It works pretty well, except that since it's a slow laptop and the iPad USB monitor connection takes its own toll, whenever I select approaches, modify route, search for FIX info etc. anything where the FMC does some more complex calculation, the computer becomes very slow in responding/updating.

Since I can't test this at the moment in a network where a more powerful computer would be the PSX server, could somebody give me an answer if there is a difference when running over network so that the server machine will do all of these more complex calculations, and the clients will just display the data from the server and send button presses/other inputs to it?

In short: Is it likely that this test I performed would work better when the laptop is connected as a client to a server instead of being a standalone PSX?

[Hardy Heinlin]

Hi Antti,

the FMC tasks you mentioned are complex but not more complex than any other sim tasks, like aerodynamics, electrical, pneumatics, autopilots etc. pp. So they are not unusual in this respect.

But the FMC tasks you mentioned include a lot of hard disk work. Maybe your system uses a very small hard disk cache or a nearly full and highly fragmented hard disk.

Such FMC tasks are performed on the PSX server only. Note that for certain features the client accesses the hard disk as well -- e.g. for map updates every few miles, terrain scanning etc. pp., all the huge data mass that isn't transferred via network.


Regards,

|-|ardy

[ahaka]

Hi Hardy,

Such a fast response! It is a very simple laptop, not something I would normally use to run any flight simulator, but I have a spare one so I decided to give it a go if I could use it as a "CDU machine"

In a network, will these tasks you mentioned be handled solely by the PSX server so the clients are "free" from this work? If I use one client only as a CDU display, will this client not need to do those calculations but only act as sort of an input/output machine?

I hope I can explain myself well enough.

[Hardy Heinlin]

I quick-edited my post above before I saw your reply. Does my quick-edit answer your questions? :-)

[ahaka]

Thanks Hardy,

Yes, that fully answers my question. When I can I will hook the laptop up to my PSX network and see how it goes. Since some of that workload is relieved from the laptop, it may be just the thing it needs to get to the normal speed.

Funny that when I was playing around with it, I imagined the very first CDUs when glass cockpits were introduced must have behaved like that in some tasks (having to wait for them to load and calculate things).

[Jeroen Hoppenbrouwers]

In brand-new aircraft, you still have to wait for the CDU when the FMS bites into the calculations, predictions, and lookups...


Hoppie

[ahaka]

Is it even common to update the FMC hardware at all whenever there's a new aircraft type/model? I bet they can't just put the latest Intel CPU at 5GHz there? Easier to go with the good old trusty and certified one?

I'm also guessing they are not aiming for the maximum processing power, but a balance between that and reliability, heat production etc etc?

[Jeroen Hoppenbrouwers]

Latest & greatest 737 FMC has a 68040 at 60 MHz and 4 MB RAM. Hardware from before 2000.

[Hardy Heinlin]

The latest 744 NG FMC needs 4 seconds to calculate the ETA and fuel for a single direct leg to an alternate airport.

[simonijs]

Hi Hardy,

Although not quite related to this subject...: my 2011 iMAC is nearing "end of life". Very slow start up, it looses connection with the internet. And within PSX: rather often it looses the thunderbolt (MacBook) or internet (PSX Remote) connection server-client, so I am planning to get me a new one.

I was offered a "2.3 i5 DC - 8GB - 256GB SSD". System requirements for PSX, however, are "2.5 GHz or higher". Is this new machine able to run PSX with 2.3 DC?

Regards,
Simon

[Jeroen Hoppenbrouwers]

Recent article on the mother of all FMCs:
http://www.bbc.com/future/story/20190704-apollo-in-50-numbers-the-technology

There are brilliant YT videos about this marvel of technology.

[Hardy Heinlin]

Hi Simon,

it's able to run PSX, but your frame rate may get lower than 70 fps. Maybe 30 to 50 fps average.

I had a 2009 iMac; it lived 4 years until 2013. The screen got darker from year to year and the inbuilt DVD drive gave up completely.

My 2013 iMac has been living for 6 years now and the screen is still bright and white. It's the best computer I ever had. I hope Apple hasn't installed a self-destruction timer.


Regards,

|-|ardy

[simonijs]

Thanks, Hardy.

Back to the shop then !

Regards,
Simon

[Phil Bunch]

Hi Hardy,

Although not quite related to this subject...: my 2011 iMAC is nearing "end of life". Very slow start up, it looses connection with the internet. And within PSX: rather often it looses the thunderbolt (MacBook) or internet (PSX Remote) connection server-client, so I am planning to get me a new one.

I was offered a "2.3 i5 DC - 8GB - 256GB SSD". System requirements for PSX, however, are "2.5 GHz or higher". Is this new machine able to run PSX with 2.3 DC?

Regards,
Simon

Here's the new Apple Mac computer that you really want...I think it may require its own nuclear power station to supply the electricity!

https://www.apple.com/mac-pro/

[Paul Mooney]

Hey Hoppie,

There's a brilliant website called Virtual AGC devoted to "the mother of all FMCs". It includes code from various missions and an emulator on which to run it. Also documents, electrical schematics, mechanical drawings etc.
Find it here

http://www.ibiblio.org/apollo/

Paul

[Jeroen Hoppenbrouwers]

Yup -- and I posted this before I think, the mother of all lectures about the AGC:

https://www.youtube.com/watch?v=xx7Lfh5SKUQ