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Kudos1 Stats

Norton chokes download speeds

I recently upgraded from my Cox 150 Mbs internet to their Gigablast service. After the service tech installed it and tested it at the modem it produced download speeds around 940+ Mbs. I then checked the download speed on my PC which topped out at about 440 Mbs. Not bad but I'm paying for twice that much.

The technician did some testing and checked the speed at one of my switches which was around 940 Mbs. He then ran ethernet from my PC directly to the modem an only received around 440 Mbs. He said it has to be a problem with the PC hardware or some software on the PC or maybe an anti-virus issue.

I called the provider that built my PC to confirm it's 1 gig capable and it is. They gave me a number of steps to try and locate the culprit. Before doing all those steps I just shut down all Norton Security services and did a speed test and got the full 940 Mbs speed.

I spoke to Norton tech support. They set up a remote session, went through various tests, cleaned out caches, temp files, etc. but still no improvement. They said there's nothing more they can do. I asked if Norton was "checking" the data as it was downloading and his answers led me to believe it was but it was difficult to understand him trying to talk around the issue. I asked if there was a way to have Norton bypass any checking during download and check the entire file in the background after the download completed. He said no.

It seems to me this is an issue for a lot more people than me and Norton needs to address the problem. Is there any way, other than this post, to raise this to a higher level in order to get some action? Thanks, Joe



Re: Norton chokes download speeds

Do you have the Norton Secure VPN installed on the computer? If so, that is going to reduce your reported speeds as the data is encrypted/decrypted from and to your computer through the VPN servers.

The Norton Security product should not be affecting your download speeds.

Things happen. Export/Backup your Norton Password Manager data.

Re: Norton chokes download speeds

Norton Secure VPN is not installed or running on the PC. I have NordVPN installed but not running at the time of the tests.

However, there is still a NordVPN service running when it's not in use. I stopped that service and left Norton running and I'm still only in the 440 Mbs range or lower. When NordVPN service is running but the program is not running/in-use and Norton is on it's in the 440 range or lower. If I turn off Norton and leave NordVPN service running it's in the 940 Mbs range again. So it would appear to be solely related to Norton.

Attached are 2 pdf files. One is a list of speed tests with an added column showing Norton's status as on or off. The other one contains screenshots of the Norton Advanced settings when it's turned on and a partial list of installed programs showing that Norton Security is installed but not Norton Secure VPN. When I turn off Norton for the tests all the green sliders are red.

Do you know if Norton is actually monitoring the download as it's in progress to check for viruses or other problems? Any other thoughts on troubleshooting?

Thanks, Joe


Re: Norton chokes download speeds

Looking at the speedtest results, you were getting some large fluctuations before you got the gig upgrade. Not sure what this could mean in all of this.

Try testing again, but start with all Norton features enabled. Then disable one feature and test. Then turn that feature back on and disable the next. Continue until you find the one that affects the speeds. Then we can dig further into what may be happening.

Things happen. Export/Backup your Norton Password Manager data.

Re: Norton chokes download speeds

Found it! Here are the results for each in Mbps:

All enabled  425

Auto protect/SONAR/Download intel (all go off with Auto Protect)  474

Smart Firewall 462

Intrusion protection 893

Email protection  463

Browser protection 463

I've always attributed the fluctuations prior to the upgrade to the time of day traffic, accessed server, or other internet issues. I fixed the 5 Mbps outlier by rebooting the router.

Let me know if you need any additional information. I have out of town guests arriving tomorrow for a few days. I'll be in and out so I may not have a chance to get back to you immediately.

Thanks for your quick follow up, Joe


Re: Norton chokes download speeds

I would not have thought that Intrusion Protection would affect your connection speed that much. I cannot comment much on this as I only have a lowly 15Mbps connection. It is enough for my needs.   So I'm not likely to notice any reduction.

Maybe others with quicker connections can test this for us.

It could also be some issue with your Norton installation. You could try running the Norton Removal and Reinstall tool to see if a clean install resolves your issue.   www.norton.com/nrnr    If you do this, be sure you run LiveUpdate manually a few times, restarting as necessary, until no updates are available.

Things happen. Export/Backup your Norton Password Manager data.
Accepted Solution
Kudos2 Stats

Re: Norton chokes download speeds

Intrusion Prevention scans all incoming and outgoing packets, and is known to cause network slowdowns due to this packet inspection.  400Mbps download speed is still more than you will ever currently need for your PC (the advantage of gigabit speeds is the increase in available bandwidth when you have multiple devices online, not really to max out one PC beyond all reasonable need), so you should definitely leave IPS enabled, as it provides important protection against software exploits and will have no effect on your online experience that you would notice in everyday use.


Re: Norton chokes download speeds


I have 150/150 speed. I just took a speed test on my computer. I got 151.75/162.85. I have the Norton Core Security Plus which is practically the same as NS.. I also have a good ISP.

Have a Good Night and


Success always occurs in private and failure in full view. Windows 10 Pro 64 bit 1903 Norton Core Security Plus Core Firmware 302 Android App 2.27 Chrome latest version.

Re: Norton chokes download speeds

Hi @joesobel,

Thanks for reporting in Norton Community Forums. I have sent you a private message requesting more details for further investigation.

Sunil_GA | Norton Forums Administrator | NortonLifeLock

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