AC3100 and Gigabit

[Kevlarmpowered]

I'm hoping you guys can help think of something I overlooked. Comcast upgraded me to Gigabit service... when they use their little device, it registered 950 (something) Mbps using my SB8200 cable modem.

Now when I plug in my AC3100, best I have managed to get thus far is 450-480mbps.

What might I have overlooked? QoS is off, Parental Controls are off, AiProtection is on (but I tried it off and that didn't change anything). Tried disabling HW acceleration, that didn't change anything. Updated to the latest firmware, 384.5. Reset factory defaults...

I'm missing something, but I can't quite see the forest from the trees.

I get the same speed registered over wifi and wired connections. AC3100 shows a 1Gbps connection to the modem.

 

[kfp]

You actually want QoS off, AiProtection off, and HW Acceleration on.

 

[Kevlarmpowered]

I turned off AI protection ... Still no change. Hovering around 450. QoS is off and HW acceleration is set to auto.

 

[roguetr]

If you remove the router and test directly from the modem are you getting the reported 950Mbps if you use the same testing method?

I'm assuming you are but best to ask

Sent from my MI 5 using Tapatalk

 

[kfp]

Hm..what does this show?

nvram show | grep ctf

I’m just wondering if NAT acceleration is still off because of some features that we forgot to list here.

 

[Kevlarmpowered]

If you remove the router and test directly from the modem are you getting the reported 950Mbps if you use the same testing method?

I'm assuming you are but best to ask

Sent from my MI 5 using Tapatalk

During install... the tech used the following...

SB8200 -> his router -> his laptop -> speedtest.xfinity.com ... reported 950ish

I'm using

SB8200 -> AC3100 -> my computer -> speedtest.xfinity.com ... reported 400-450ish

I haven't plugged my computer directly into the modem yet because I have to tear it all down to accomplish that (I really need a laptop with a network jack). This is on my list of things to try but just isn't easy to tear it all down and put everything right next to each other.

 

[Kevlarmpowered]

Hm..what does this show?

nvram show | grep ctf

I’m just wondering if NAT acceleration is still off because of some features that we forgot to list here.

ctf_disable=0
size: 61403 bytes (69669 left)
ctf_disable_force=0
ctf_pt_udp=0

 

[roguetr]

I know it's a pita but you really want to test the two, one after the other just to rule out something upstream since the install.

I only say this as your router isn't uncommon and you'd think you'd see more reports if it's something settings related. It's entirely possible that it's uncommon for someone to have a gigabit connection in combination with this router but I'd doubt it.

Sent from my MI 5 using Tapatalk

 

[kfp]

ctf_disable=0
size: 61403 bytes (69669 left)
ctf_disable_force=0
ctf_pt_udp=0

Hmm.. nothing look out of place.
Maybe try what @roguetr suggested? Bypassing the router and see if you’re really getting the full 1Gbps.

Other things to try:
- reset the router by clear NVRAM (hold WPS button during boot)
- “Forget Network” on your client devices and enter the password again

 

[Kevlarmpowered]

Took everything apart... ran a wire directly from computer to modem. Yup, something is wrong. Doesn't look to be router based. From computer -> sb8200, I'm only getting the same 450. So I'm back on the phone with comcast to have them reprovision the modem to see if that helps. If that doesn't work, I'm going to have to get a tech back out here (at which point in time they will start scratching their heads too).

 

[roguetr]

That makes a lot more sense. Being a cable network, you could try testing at staggered times to see if it's a peak vs off peak congestion issue ...

Because it wouldn't surprise me at all if they replace/reprovision and end up with the same result.

Sent from my MI 5 using Tapatalk

 

[Kevlarmpowered]

Argh!

Turns out my desktop is the weak link. I got another laptop and plugged it in and I'm hitting 935-960mbps.

Now I have to buy a new computer...

 

[kfp]

Argh!

Turns out my desktop is the weak link. I got another laptop and plugged it in and I'm hitting 935-960mbps.

Now I have to buy a new computer...

Sounds like a good problem to have [emoji41]

 

[RMerlin]

Just get a new NIC.

Sent from my P027 using Tapatalk

 

[doczenith1]

What OS are you running? I have an older computer that only does around 200/700 Mbps down/up on website speedtests but when I run the Ookla speedtest Win 10 app I can get my full 940/940. In my case my computer's cpu is the weak link.

 

[Kevlarmpowered]

The NIC is displaying a 1Gbps connection...

I'm running Windows10 on an Asus P8Z68V Pro motherboard with an i7 3770K CPU.

 

[kfp]

The NIC is displaying a 1Gbps connection...

I'm running Windows10 on an Asus P8Z68V Pro motherboard with an i7 3770K CPU.

Maybe try updating the NIC driver?

 

[Kevlarmpowered]

Tried updating the driver... no dice. I even tried disabling the eco-friendly power saving mode that it has, no luck. I'm going to see if I can acquire an additional NIC card and see if that does anything or if the motherboard/CPU are just too old.

That is pretty bad though... the port advertises a 1Gbps connection but it can only use about 500Mbps worth.

 

[kfp]

Tried updating the driver... no dice. I even tried disabling the eco-friendly power saving mode that it has, no luck. I'm going to see if I can acquire an additional NIC card and see if that does anything or if the motherboard/CPU are just too old.

That is pretty bad though... the port advertises a 1Gbps connection but it can only use about 500Mbps worth.

Have you tried using different cables/ports that are known to work on other devices?

 

[doczenith1]

My i5 2500K can hit my full 940 Mbps on website speedtests using the motherboard Realtek RTL8111E nic. I agree with kfp that it might be a driver or cabling issue.