Garmin "thinks" they've figured out the 910xt pace problem and they have a suggestion... (Page 2)

Ah!  I see.

The only time I've ever seen mine do that is if I start moving shortly after the device indicates "satellites found" rather than waiting for it to connect to additional satellites to improve the accuracy.

Once it says it's connected to satellites, check the accuracy through the menu button to make sure it's not still 50' or 60'.  Instead, wait for it to indicate accuracy is less than 20' before starting.  IME, doing this provides very stable instant pace readings.

Has anyone else experienced the same thing, or have you seen unstable readings despite a good accuracy number?

ETA:  BTW, I'm still using firmware version 2.60 which came installed.  I've never upgraded, and have never experienced any of the issues reported by others, except for instances where I could identify user error on my part.

I also work in the software industry, and the explanation makes perfect sense.  There are often multiple different codepaths that each may need to do a few things differently.  I can imagine out-of-box startup, mode switch, soft reset startup, power-on-from-hibernate (a version of warm start), and so on.  Their explanation is that power-on-from-hibernate fails to init something correctly and mode switch does. 

BTW, I used to use instant pace on my 310 a lot but yes it wobbles like crazy on the 910xt.  To compensate for this, what I did was set the Garmin to auto-lap every .2 miles (1/5 mile).  What this does is cause the watch to vibrate every 1/5th mile and then I look at the watch, and see the average pace for that lap.  If I'm  targeting 10 minute miles, then that's 2:00.  For 9 minute miles, 1:48 per 1/5th mile. 

This has worked out really well for me.  I no longer have this constant OCD-ish glance at my watch.  Instead I just run along, it vibrates, I look, I see the pace, and I either speed up a bit if I'm lagging behind my target or slow down if I'm getting a bit fast.  If I stop for a water break, then the lap may say "2:10" instead of "1:48", and that means I gave away 22 seconds off my pace for that water stop.  This is so much more useful info than the having auto-lap set to every full mile.

I ran a full marathon with this setting as well as a HIM run, and I was very pleased with this setup.  I'll keep using it even after the average pace is fixed.

This is a really good idea.  I just tried it on my 210 and while I can only go down to 0.25, it works like a charm.

Do they also mention you have to dance around naked outside while wearing the watch on your left ankle for 15 minutes before using it?  That seems like an unlikely fix, but yet for some reason I will try it

Originally posted by mike761 When I want to know how fast I'm running I look down at my 305! It gives me my pace with no problems Maybe Garmin should go find the guys who designed the 305 for them and have them fix the 910.

I also use the FR305 and rely on instant pacing all the time.  Not sure I would ever upgrade to the 910 if this is an ongoing bug.