IPv4 Slow Upload on one computer [Comcast]

[WarnUs]

I can't seem to figure out what is causing this. I have two computers hard wired into my modem/router and they have different results for IPv4 upload speeds. My windows 8.1 rig has a 1.49 Mbps upload speed on IPv4, while it has an upload speed of 11.16 on IPv6. My windows 7 rig has 11.74 Mbps upload on IPv4, and an upload speed of 11.66 Mbps on IPv6.

This leads me to believe there is a software or driver issue somewhere on the rig running windows 8.1. I'm not sure what to do to fix it, and it's causing huge issues trying to upload streaming video to twitch.tv.

I've attempted to fix this by disabling Large Send Offload v2 (IPv4), but it didn't seem to help. I read a post in the comcast forums talking about a guy on windows 7 who had this exact issue, fixed it by doing this changing this on his ethernet controller.

Changed two settings in the advanced configuration:
Large Send Offload (IPv4) Enabled => Disabled
Large Send Offload v2 (IPv4) Disabled => Enabled

I can only find Lard Send Offload v2(IPv4) and it is default enabled, I can't find the other setting in windows 8.1

 

[carnageX]

Have you gotten the latest drivers from the ethernet controllers' website?

 

[WarnUs]

Yeah, unfortunately I have, I just tried installing the drivers again too. It has an ASROCK Z87 Pro4 Motherboard which has an intel (R) Ethernet Connection I217-V. I've gotten drivers from both the ASROCK website and the intel website.

 

[WarnUs]

I found out the problem! After more and more googling I found this post in another forum.

I FOUND THE SOLUTION.

Since ASRock Motherboard comes with the Xfast Lan sort of stuff,
I uninstalled that and it was the factor that was limiting my upload speed.

I hope I solve others' similar issues if they have the same brand motherboard.

It worked for me!

 

[carnageX]

Interesting. Glad you got it figured out, and thanks for sharing your solution!