Network speed issues

[philp]

I'm on Comcast's blast internet and have 3 computers on the network. On my laptop I have no problems: http://stage.results.speedtest.comcast.net/result/496901124.png

 

My wife's Windows 8 Home HP desktop is another story: http://stage.results.speedtest.comcast.net/result/495662544.png

 

I also have a Windows 7 Pro desktop that gets similar or worse speeds. Yeah, I know we don't trust these types of tests, but I don't understand why there is such a huge difference. Anyone got any suggestions?

 

BTW, I am not 6100 miles from Chicago and don't know why it shows that.

[philp]

Here's a follow up. I have uninstalled and reinstalled the wireless adapter drivers on both desktops. Retesting showed no improvements. I pulled my D-Link router out of retirement, connected it to the Comcast router and the speed on one desktop went from 5.41 Mbps to 33.74 Mbps when connected to that router. I switched back and forth 3 times to verify it wasn't a fluke and got similar results each time. On the other desktop, I went from 14-15 Mbps to 33-35 Mbps.

 

Normally this would point to a 3rd faulty router (yes, 3 in one week) but as noted before, my laptop has no speed problems at all. Here is this morning's test on the lappy: https://testmy.net/db/yZLEuer

[j7n]

I have uninstalled and reinstalled the wireless adapter drivers on both desktops.

Maybe the D-Link access point has a stronger signal than the other one? If they are operating on different channels, maybe there is more interference in part of the spectrum? A router with tools to monitor link quality and spectrum would allow pick the best channel. Why are you connecting a desktop computer via wireless?

[philp]

One desktop is in a different room and the other is across the room from the router making cable connections inconvenient. I've tried different channels. Signal strength is 85% on the Comcast and 100% on the D-Link. I wouldn't think that would make much difference especially since my laptop can be anywhere in the apartment and not show speeds as low as these 2 desktops. It just makes no sense.

[mudmanc4]

Just for analytics, I might try and set QOS on the highest performing device, to lower than the max achieved on the lowest performing device. 

 

Whatever your findings would you post them please

[TriRan]

Are all of your devices connecting with wireless N?

[philp]

Are all of your devices connecting with wireless N?

 

Yes, all are wireless N. Good thought, though and I appreciate any suggestions.

 

Mudman, I will see if I can follow your suggestion tonight. Not sure how to do it, but if I can't figure it out, I'll be back.

 

BTW, would that make a difference if only one computer at a time is powered on?

[j7n]

Are all devices actually establishing and maintaining links in "N" (HT) mode or falling back to a slower speed occasionally or during data transfer? It is possible that one device with poor reception (indicated by low signal strength or lower link speed; due to a fault of either the station or the AP) slow down the entire network by reserving airtime to themselves. You would want to ensure that they can all maintain at least stable 54 MBit/s "G" (around 20 MBit/s real throughput).

[TriRan]

J7n that us mostly correct looks like he has blast Internet though so he would need to maintain around the 108mbps

[nanobot]

Due to the operation mechanisms of Single-Channel Wireless Technology, your throughput per connected device will never exceed (wireless bandwidth)/(n+1), where n is the number of devices transferring data, and the wireless bandwidth is the Mbps rating.

This is because wireless is a shared medium, and uses CSMA/CA. (Carrier-Service Multiple-Access Collision Avoidance). Before a packet is sent, the Wireless Device sends an RTS (Request to Send) and must receive a CTS (Clear to Send). (Ethernet, on the other hand, uses CSMA/CD. Carrier-Service Multiple-Access Collision Detect. It doesn't use RTS or CTS, it just sends data. If it finds a collision, where two devices on one medium transfer at the same time, it stops transmitting, and all devices active a random backoff timer, and when their timer expires they try again.)

Thanks,

EBrown

[philp]

So, would it be the Comcast gateway that's a piece of crap? The desktops get low DL speeds even if nothing else is even powered on. But if I test through the D-Link router (which is hardwired to the Comcast gateway), I can have both desktops, my laptop and 2 iPhones on the network and download speeds are in the 30-32 Mbps range.