I have a GigE internet connection. When I’m not running MSFS on my PC I routinely get 100 to 800 mbps downloads. When MSFS is running I get from 6 to 30 mbps. When I close msfs my downloads are still slow. After I reboot the PC download speeds return to good until I restart MSFS. Download screenshots follow:
with MSFS running:
with MSFS not running:
You should read this post:
If for whatever reason your upload gets saturated it will trash your download rate as well. I used to see that all the time with Bittorrent clients. When seeding you had to leave yourself some overheard on upload, and don’t let the upload stream hit capacity as it doesn’t have enough bandwidth to manage the downloads. I’ve never run a bandwidth test with MSFS running so I’m kind of curious to try that now!
It looks like you just had the sim open with no flight loaded, but it wasn’t clear whether you were downloading any updates as the top of window indicators were covered by the speed test results.
I didn’t have a flight running. No MSFS downloads were taking place at the time of the download test. I just had msfs running. This problem has been persistent for months. I’ve done a good bit of troubleshooting and am convinced the MSFS is somehow slowing all data transfers, in game and out of game, to and from my PC.
I recently uninstalled MSFS and reinstalled. The problem persists.
Also, my son also has and plays MSFS on his PC behind the same internet connection. He does not have download problems. He regularly gets 300 to 400 mbps speeds.
It’s not typical MSFS behaviour though. Are you 100% certain you don’t have a mining bot or similar on your system? it may be worth doing an offline scan in windows security.
Nothing else is running or using bandwidth. Confirmed thru task manager and Wireshark.
That’s not the point, malware can also break/change settings while attempting to connect.
If it was malware then why would it be selective and only cause problems when MSFS is running?
One scenario would be it could be attatched to some dubious freeware addon, I don’t have a clue what you have on your system.
My point was that despite quite a large contingent of users with internet problems, you seem to be the only one reporting on here with this particular issue. For me that makes it difficult to see why it should be a problem with the sim itself.
What does task manager show for network usage while running MSFS?
I am wondering about RAM utilzation. I only have 16 Gig and task manager shows approx. 50% utilization while running MSFS.
Is there a reason you’re running 2 graphics cards? Not that I’m suggesting this is remotely connected, I’m just being nosey. Has this problem always affected you or has it started happening recently, for example after a Windows update?
Also, you mention you have 16gig but task manager shows 13.9.
I hadn’t noticed the RAM listed at 13.9 gig. My PC is a lenovo gaming 3 laptop. It has two 8 gig DIMMs. It came with one, and I added one. I’ll research the 13.9 gig issue on my PC.
My PC has a Ryzen 5 5600H with a built in graphics card as well as an NVIDIA RTX 3050 TI. Should I disable one of them?
The poor download speed only occurs when I’m running MSFS, or after running MSFS without rebooting the PC.
It is a very weird problem.
Yes, definitely, disable the onboard graphics. Although, the bios should automatically do this when a discrete GPU is installed. As for the RAM, check they are in the correct slots, your motherboard manual will state the correct installation of them.
As for the download speed, could be a goosed wifi adapter, try a wired connection to see if it does the same thing.
