To study the effects of the threshold increase, from current 3 to proposed 4, of an altro digitizer chip, on tracks, separete simulations were performed with these values.
Simulations are for the 2014 STAR geometry.

"Anti-Efficiency" results for both cases are shown on the plots below for negatively and positively charged tracks separately:

These plots show that reconstruction efficiency is not affected by raising the threshold value.

Below plot shows the comparison between two cases for the number of hits for tracks. The difference is insignificant from these comparisons 1as well.

Below is the fficiency comparison for the simulated data with nHits per primary track is greated than 15:

This plot shows that despite loss of the hits due to the higher trheshold the efficency is slightly increased.

The effect is more pronounced for the AuAu 2014 data (perhaps due to the pileup removal by the higher threshold):

Yuri has performed same study on the recent data which were taken with both threshold values in different runs. The results are on this link:
drupal.star.bnl.gov/STAR/blog/fisyak/compare-primary-track-quality-runs-16132028-normal-parameters-and-16132032-changed-daqal
The data doesn't show significant changes either.
=============================================================

To check the difference between simulation and Yuri's data results I have produced and embeded sample of the simulation into the zero bias sample of y2014 Au-Au data that Yuri used for his study. The embeding was done for both threshold scenarios. The result is shown below:

SUMMARY:

The effects of Altro threshold encrease from 3 to 4 are studied. Slight increase in track reconstruction efficiency is observed in both simulation and high luminosity 2013 Au-Au data analysis. The increase seen in high luminosity data is much greater than the effect seen in simulation which is due to the high pileup in data which is not present in simulation. To confirm this assumption the same simulation was embeded in the 2014 Au-Au data that was used for the data analysis, the result shows that the difference between two treshlod scenarios is more pronounces in the high pileup environment.