Uwatec Smart Z data download takes 1.5 hours for only 4 dives

[Dirk Hohndel]

On Sat, 2013-12-28 at 14:51 +0100, Sape Sikkema wrote:
> Dear development team,
> 
> Thanks for your relentless efforts to solve my problem. If I understand 
> correctly there are two issues:
> 
> 1. Subsurface always downloads all dives from the Uwatec Smart Z device 
> because of the fact Subsurface does not use the fingerprint feature.
> 2. Some drivers / kernels have an effect on the transfer speed.
> 
> On Jef's request I did some test with different linux kernels and 
> different hardware to download all 102 dives from the device using both 
> SmartTrak and the libdivecomputer universal application. Here are the 
> results:
> 
> Desktop Pentium 4 2.8 GHz, 2 GB RAM:
> 
> 1: Universal, OpenSuse 13.1 kernel 3.11.6-4-default:     77 mins
> 2: Universal, Xubuntu 12.04 kernel 3.2.0-52-generic (live-CD): 18 mins
> 3: SmartTrak, OpenSuse 13.1 kernel 3.11.6-4-default + Wine:       80 mins
> 4: SmartTrak, Windows XP:                   13 mins
> 5: Universal, Windows XP:                     12 mins
> 
> Netbook Acer Aspire One ZG5, 1 GB RAM:
> 
> 4: Universal, Ubuntu 12.04 kernel 3.2.0-57-generic:     18 mins
> 6: Universal, OpenSuse 13.1 kernel 3.11.6-4-default (live CD): 80 mins
> 
> Hope this helps you to find the root cause of the slow data 
> transmission. Let me know if I can do more.

So the common theme is that wherever you run 3.11 you get excessively
long download times, where you run 3.2 things are similar to Windows.

Linus, any idea why a two year old kernel would be more than 4 times
faster? This is with an irda connection...

/D