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FIPs lagging Virtual Cockpi Instruments

Posted: 01 Dec 2018, 05:29
by Steve Horsfall
Due to a Hard Drive failure, a new Solid State Drive was fitted to my Sim PC and loaded with Win 7 (did not like Win 10!) and upgraded RAM to 16 GB. Managed to reload SPAD and Licence and the backup of FSX-Steam. Lost my SPAD profiles, many hours rebuilding. The FIPs have a 5-10 second lag behind the Virtual Cockpit View and the contrals on the instrument panels also have a lag. The Sim has been working for 3 years, and was upgraded from Saitek to SPAD early this year.
I have spent many hours tweaking FSX settings to get the Sim back to normal, the scenery and other traffic has been set to the lowest level and frame rate adjusted to low to see if the CPU was getting stressed :?
Have 6 FIPs, Multi Panel, Radio Panel, Switch Panel, Yoke and Quadrant and Rudder Pedals. These are connected to 2 x 7 port powered USB 3 hubs rated at 4 amps.( previously had a 10 port hub, but it expired due to overload ) :oops:
Any suggestions would be greatly appreciated.

Re: FIPs lagging Virtual Cockpi Instruments

Posted: 05 Dec 2018, 09:54
by c0nnex
First of all, do not, I repeat do NOT, connect FIP to USB 3 - ports! Saitek/logtech FIP do not support USB3 and are not compatible! It might work, but in most cases you will notice strange things like eg. FIP lagging/crashing
If you notice FIP lagging behind a lot, this is always an USB issue.

There is a big diffrence between saitek driver-implementation and SPAD.neXt implemetation of the FIP. While Saitek limites all connected FIP to "only one fip may be updated at a time" , SPAD.neXT does not have such a limitation (thus allowing up to 16-20fps on the fips).
The downfall of this is that
a) FIP use a lot more power than "allowed" by USB specs. They draw up to 1.5 A when updating often. (just do the math. 6 Fip x 1.5A + 0.5A space = 9.5 Amps needed to drive the fip!) If the USB Hub fails to deliver enough power to the fip, it will simply crash (stop responding).
b) Due to Saitek fip not being USB3 compatible, attaching them to a usb3 port/hub that is not fully usb2 compatible, may cause lagging, becasue the fip will not tell the USB "hey i am busy wait a bit", causing an "usb traffic jam" (hub resending the stuff to the fip until it acknowledges it)

Re: FIPs lagging Virtual Cockpi Instruments

Posted: 06 Dec 2018, 04:21
by Steve Horsfall
Thank you for the information. I did update my hubs from USB 2 to USB 3, I did not suspect that this was a problem, as I was told the hubs were backward compatible. Would the USB 3 Hubs also not be compatible with the Radio and Multi Panels as they lag as well, or is it a side effect with the FIP causing congestion in the Hubs

Re: FIPs lagging Virtual Cockpi Instruments

Posted: 06 Dec 2018, 18:48
by c0nnex
It can be a side effect.
Does the Radio/MP also cause delayed reactions in the sim if you press a button etc?

Re: FIPs lagging Virtual Cockpit Instruments

Posted: 08 Dec 2018, 04:31
by Steve Horsfall
There was delayed reactions when the buttons were pressed.I disconnected the FIPs but left the Radio/MP/SP/ yoke and rudders connected. All seems ok with these panels etc and no delay. I did swap these to a USB 2 powered hub and then again to the USB 3 powered hub and it seems like the panels etc, work ok on USB3.
The FIPs are now connected to USB 2 powered hubs and all is back to normal. :D

Re: FIPs lagging Virtual Cockpi Instruments

Posted: 11 Dec 2018, 00:36
by jdavidpugh
I just want to chime in here regarding the statements about power requirements for the FIPS.....
While it may be true that the individual port currents may reach pretty high levels I doubt they will ever exceed 750ma..
If that was the case there is only one or two USB hubs I have ever seen that would sufficiently supply them.
I currently use this guy:

https://www.newegg.com/Product/Product. ... -_-Product

And every port is filled........including a few USB monitors, my FIPS, and flight controls. 750ma per port and very rarely any issues with crashes.

It only has a 4.5 Amp 20V power supply

The biggest one I have ever seen is only 1000ma (1A) per port unless you delve into "Charging" ports for Tablets and Cellphones.
They are the big boys with 2400ma (2.4A 12W) per port. These are rare and usually are only a couple of ports on a multiport hub.

Barring this beast:

https://www.newegg.com/Product/Product. ... -_-Product

Keep in mind the voltage on the supply side is usually around 20V and on the device side 5V so a 4amp 20V supply can deliver 20amps on the 5V side of the hub. V=I*R V is voltage, I is current, R is resistance.

Say we have 20 FIPS @ 1000ma (1A) each = 20amps on the 5V side.
5(V)=20(I) * R, R= 4 Ohms.
Now on the other side of the hub power supply...
20(V)=I *4(R), I = 5Amps

Now before the EE's in the room chime in there are some negligible losses in efficiency but you get the jist........

So for discussions sake just to make sure we are comparing apples to apples....

David

Re: FIPs lagging Virtual Cockpi Instruments

Posted: 11 Dec 2018, 16:21
by c0nnex
Read again what i wrote... they draw more than a normal HUB can deliver.
My working solution for 15 FIP : I serve them using 5 7-Port Hub, with only 3 FIP per HUB. Works like a charm not a single FIP failed in the last 3 Years.

Re: FIPs lagging Virtual Cockpi Instruments

Posted: 11 Dec 2018, 16:38
by jdavidpugh
What are the specs on your hub you are using?

Re: FIPs lagging Virtual Cockpi Instruments

Posted: 11 Dec 2018, 16:51
by c0nnex
I am using this hubs: https://www.amazon.com/dp/B009C150XA/re ... 11_TE_dp_2
They are speced for 3A , but is able to provide it constantly even under full usage. So it's fine with 3 FIP.
As soon as i attach a 4th one ,or any other saitek device, fip will start to "die" every now and then

Re: FIPs lagging Virtual Cockpi Instruments

Posted: 11 Dec 2018, 17:04
by jdavidpugh
And I was not discounting the fact that they draw alot of power. They will task a 500ma standard USB port. My statements pertained to the methodology used to determine power supply sizing. And my 750ma per port 20 port hub has never blipped with 9 FIPS all flight controls and 2 15" USB monitors attached. In all 19 devices attached to 1 hub with a 4.5amp power supply........
Image
If by some slim chance they were drawing the max of 750ma per port that would equate to 15000ma or 15amps on the 5V bus........but since its a 20V supply to the hub voltage regulator the draw seen on the power supply side is only 3.25 amps max.

All I am saying is you cannot use the estimated draw of the FIPS alone to size the power supply without taking into account the supply voltage of the supply to the hub. The cheaper hubs typically use a little "wall wart" supply which cannot supply full power to all the ports at once. And from personal experience it will let you know when its too small when you let the smoke out of it! :D

David