Referee report paper 48 
This paper assembles a variety of interesting performance studies of the ALICE silicon tracking detectors. I support its publication with a 
few minor comments that need to be addressed:
1.	Fig. 1 is really almost unreadable when printed in black and white, and the details of the detector description would make more sense 
if the illustration corroborated the words. I find the detector description the harder section of the manuscript to follow.
2.	Figure 2: make the symbols bigger. 
3.	Figure 4: the square root symbol is hard to see.
4.	Figure 6: can the MC/data resolution at low pt be related to how well the detector material is known?




Answer to the Referee report:

I acknowledge the comments of the referee and I send back a revised version of the draft which takes into account them. 
I add a few remarks for each referee comment.
 1. Comment 1: I changed Fig. 1 in order to improve the quality.
    Following the referee comment on the hardness of the detector description section, I changed the text cutting some parts at the end of the section.
 2. Comment 2: Unfortunately to change the figures takes longer time than that available to send back the manuscript. This is due to the fact that these 
     are official ALICE performance figures done not by me and I need to follow some internal procedure to request a change.  
    I enlarged the figure dimension in order to have also bigger mark. I hope this fulfill the referee request.
 3. Comment 3: As described for figure 2 I requested the change of the square root dimension but some time is needed to have it. I am really sorry for that. 
 4.	Comment 4: The answer to the question is yes: the low pt resolution discrepancy depends on the detector material description present in the MC code.