Board index FlightGear Support Hardware

CPU more cores or more speed?

Joysticks, pedals, monitors.

CPU more cores or more speed?

Postby dom_vc10 » Wed Nov 24, 2021 3:43 pm

I am currently looking to upgrade my CPU from my wonderful AMD Phenom II X4 965. It's overclocked to the max and does a good job but really struggles with using anymore complex aircraft. So I have a massively small budget, around 280 Euro so the scope is small. I will obviously need a new motherboard and ram to go with the new CPU which eats that budget up.

The main question is what to look out for in a CPU, my understanding is that FG would be best with a CPU that has a faster core rather than more cores is that the correct assumption?
dom_vc10
 
Posts: 186
Joined: Mon Jul 27, 2020 7:33 am
Location: CZ - LKTB
Version: nightly
OS: Linux Mint 20.2

Re: CPU more cores or more speed?

Postby V12 » Wed Nov 24, 2021 6:53 pm

Try fastest possible i3. AMD CPUs have low singlecore performance, avoid him if You can.

FG is not optimized for multicore CPUs. My R7 3700X can run P3D 5.2 without any troubles, stutters free and 25 fps even in heavy multilayered cloud weather, but badly stutters with unoptimized FG and clear skies.

With i3-10105F in FG You will have almost same performance as me with R7-3700X.
Fly high, fly fast - fly Concorde !
User avatar
V12
 
Posts: 2579
Joined: Thu Jan 12, 2017 4:27 pm
Location: LZIB
Callsign: BAWV12

Re: CPU more cores or more speed?

Postby dom_vc10 » Wed Nov 24, 2021 8:16 pm

i3-10105F. That is the exact processor I was looking at before I wrote the post :D I am glad I am on the right path it's been a few years since I really looked into this. Thanks
dom_vc10
 
Posts: 186
Joined: Mon Jul 27, 2020 7:33 am
Location: CZ - LKTB
Version: nightly
OS: Linux Mint 20.2

Re: CPU more cores or more speed?

Postby V12 » Wed Nov 24, 2021 9:15 pm

And what about GPU ?
Fly high, fly fast - fly Concorde !
User avatar
V12
 
Posts: 2579
Joined: Thu Jan 12, 2017 4:27 pm
Location: LZIB
Callsign: BAWV12

Re: CPU more cores or more speed?

Postby dom_vc10 » Thu Nov 25, 2021 8:12 am

I already have a gtx1050ti I will stick with that so far the bottleneck for FG is my processor and with GPU prices right now I am more than happy to stay with that.
dom_vc10
 
Posts: 186
Joined: Mon Jul 27, 2020 7:33 am
Location: CZ - LKTB
Version: nightly
OS: Linux Mint 20.2

Re: CPU more cores or more speed?

Postby vnts » Thu Nov 25, 2021 11:34 am

dom_vc10 wrote in Wed Nov 24, 2021 3:43 pm:So I have a massively small budget, around 280 Euro so the scope is small. I will obviously need a new motherboard and ram to go with the new CPU which eats that budget up.

[..] my understanding is that FG would be best with a CPU that has a faster core rather than more cores is that the correct assumption?


It depends on how long your current upgrade cycle is. If it's a lot more than an year - FG performance is a changing and unknown target. The next LTS with WS3 terrain, WS3 roads, compositor, planned new GUI etc. will be very different - final WS3 performance is unknown. In some ways FG will be faster , with scripts to merge scene objects to reduce OSG nodes, old OpenGl being replaced when the new GUI comes in, any OSG optimisations, various optimisations, multi-thread safe property tree. For example WS3 terrain is already less CPU bound due to using fewer OSG nodes. However, there will be new features to enable that will use up spare performance.

You will also need new RAM with a new MB - it's also unknown what the RAM requirements will be, as well as what the benefits are for having more RAM .

The best indication of future performance will be after the next LTS releases - and by then there might be a new CPU generation out - and CPU/MBs could be cheaper for the same performance. The shortages due to the pandemic might also have lessened.

You should look at various prices and options using the CPU benchmarks linked on the wiki: https://wiki.flightgear.org/Hardware_re ... 2018.3_LTS

You should also look at current GPU utilisation with various graphics settings and aircraft. For example if GPU utilisation is 80%, a faster CPU can give 1.0/0.8 = 1.25, or 125% more FPS. If a CPU that is 2x faster is used instead, there will still be only 25% more performance.

Kind regards
vnts
 
Posts: 399
Joined: Thu Apr 02, 2015 12:29 am

Re: CPU more cores or more speed?

Postby dom_vc10 » Thu Nov 25, 2021 12:57 pm

Yes agree. Budget is the killer for now. I know what I want but it comes down to what I can get so this is kind of an interim solution. The biggest blocker right now on my system is my CPU. It's old, I've overclocked it to 3.9 but it still struggles. With aircraft like the 172 I am getting a solid 20fps with photoscenery full OSM etc and the GPU is not being taxed so much. I would really like to get some airliner flying going but the framerates jump a lot from 20-8 when the CPU maxes out. So new MB, 32gb ram and new cpu I should be good to go for a few more years I think and hopefully the money tree can grow in the meantime.

Thanks for the details though I very much appreciate it I will take a closer look :wink:
dom_vc10
 
Posts: 186
Joined: Mon Jul 27, 2020 7:33 am
Location: CZ - LKTB
Version: nightly
OS: Linux Mint 20.2

Re: CPU more cores or more speed?

Postby V12 » Thu Nov 25, 2021 5:41 pm

Your GTX1050 is good enough for FGFS. With noted i3-10105F You will obtain decent machine for all aircraft in FGFS.

Fly high, fly fast - fly Concorde !
User avatar
V12
 
Posts: 2579
Joined: Thu Jan 12, 2017 4:27 pm
Location: LZIB
Callsign: BAWV12

Re: CPU more cores or more speed?

Postby clm76 » Tue Nov 30, 2021 10:43 am

Hi V12,

What program do you use to display performance of CPU and GPU on your video ? Is it with Windows or linux ?
clm76
 
Posts: 202
Joined: Tue Oct 30, 2012 8:18 pm
Location: France - LFOH
Callsign: F-GCLM
Version: 2020.4.0
OS: Linux Mint 20.2

Re: CPU more cores or more speed?

Postby V12 » Tue Nov 30, 2021 12:12 pm

Linux, MangoHUD. More info at https://github.com/flightlessmango/MangoHud
For some distros exists precompiled packages installable via package managers.
Fly high, fly fast - fly Concorde !
User avatar
V12
 
Posts: 2579
Joined: Thu Jan 12, 2017 4:27 pm
Location: LZIB
Callsign: BAWV12

Re: CPU more cores or more speed?

Postby clm76 » Tue Nov 30, 2021 6:08 pm

Thanks V12 for MangoHud.

I am with Linux Mint 20.2, so I installed it from the ppa. Now I have 3 questions :
1 - where is it installed ?
2 - where is the config file installed ?
3 - the most important : how to launch MangoHud with Flightgear
clm76
 
Posts: 202
Joined: Tue Oct 30, 2012 8:18 pm
Location: France - LFOH
Callsign: F-GCLM
Version: 2020.4.0
OS: Linux Mint 20.2

Re: CPU more cores or more speed?

Postby V12 » Tue Nov 30, 2021 7:03 pm

Read the manual, all is perfectly documented.
1. irrelevant
2. $HOME/.config/MangoHud/MangoHud.conf
Insert word full for all available params
3. mangohud fgfs --launcher
Fly high, fly fast - fly Concorde !
User avatar
V12
 
Posts: 2579
Joined: Thu Jan 12, 2017 4:27 pm
Location: LZIB
Callsign: BAWV12

Re: CPU more cores or more speed?

Postby clm76 » Wed Dec 01, 2021 10:00 am

Many thanks V12, MangoHud configured and run with fgfs. Very useful.
clm76
 
Posts: 202
Joined: Tue Oct 30, 2012 8:18 pm
Location: France - LFOH
Callsign: F-GCLM
Version: 2020.4.0
OS: Linux Mint 20.2


Return to Hardware

Who is online

Users browsing this forum: No registered users and 1 guest