Speed vs. Hops

So I have now recorded data for myZ-Wave devices 69 times. I have data for the average speed (100 * # devices at 100) + (40 * # of devices at 40) + (9.6 * # of devices at 9.6)/# of devices (which in my case happens to be 49).

I also calculated the average # of hops per device using a similar type of calculation. I then calculated the average speed per hop.

I also calculated the correlation between average speed and average hops. While it naturally varies a bit from day to day the final # is -0.51426077. The range for a correlation is -1 to +1 where -1 is absolutely no correlation while +1 is a 100% correlation. My -.51 means there is a moderate non-correlation (i.e. there is moderate evidence of no correlation).

There was one thing I did that made a tremendous difference. My C-8 is plugged into a TP-Link satellite router. As they are on top of a wall unit I had laid my TP-Link on its side so it wouldn't be visible. On the 9th day of my data point I stood it upright. That instantly brought a big jump up in my data speeds and reduced my # of hops dramatically. I know Hubitat suggests having the hub about a foot away from the router, but I never saw anything about the orientation of the router (and I had assumed it was spherical to get the best all-around coverage). One of the reasons I went with Z-Wave vs. Zigbee way back when was I had read that Zigbee was at 2.4, the same as one of the WiFi frequencies. So I'm very surprised that the orientation of the TP-Link satellite had such a profound effect on it.

In any event, here are a couple of charts showing my results. Because the # of hops is between 1-4 and the speeds are 9.6-100 the # of hops was so small that the differences were very hard to make out. So I made another chart with just the # of hops and overlaid it on the other chart and made it transparent so you could see those fluctuations better. (BTW, there was 1 day where 1 device was at 4 hops, but I didn't include 4 hops in the 3rd chart, but it was used in calculating the average # of hops per device and the speed/hops)

One final note: The #'s for the C-8 in both average speed and average hops were worse than the C-7 when the TP-Link was on its side. But I did not hook up C-7 back up once I stood the TP-Link upright so I can't say how it would have preformed with the TP-Link standing upright. As such, I can't say if the C-8 is "better" than the C-7 or not.

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I’ve never seen that suggested. Usually a minimum of 3 to 6 feet is better, my C-8 and C-5s are closer to 10 feet away from my router. The vast majority of my devices are Zigbee, but of the 30 Z-Wave devices I have, 29 are directly connected, and all are 100kbps.


I have to agree with @Ken_Fraleigh here. I am pretty sure the statement has always been to keep your wifi router atleast 3-6 feet aprt if possible and more is even better. This has to so with the radios essentially over powering each other.

My setup has 53 zwave devices. 41 are direct and 40 are at 100kbps while the rest are at 40kbps. I also extensively use S2 for security.

Also make sure on the hubitat you put the antennas straight up or down and not at angles. The dont send the radio out in a perfect sphere but more to the sides then verticle.

I'll try moving the router even further away and see what happens.

I’m struggling to understand how you’re able to use all of this information in a way that is helpful.

Isn’t the problem with a WiFi access point being too close to the hub related to zigbee interference? They both operate at 2.4 GHz. Z-wave (in the US) is on 908 MHz.


Also it appears this thread is a duplicate of another one of the OP’s threads. @bobbyD please consider merging posts, thanks.

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I kept reading about how people had so many more devices directly connected with the C-8 vs. the C-7 and I wanted to see if there was any correlation between the # of hops and speed.

Really the only way that comes into play is let's say you have a repeating device that is max 40kbps and you have a device who's max is 100kbps. If due to signal strength etc, that a more optimal route through the 40kbps unit is chosen, then the 100kbps unit will drop down to 40.