web server - average memory

That would depend entirely on the number of concurrent visitors and the memory consumption of each of those visitor processes.
Web servers need very little memory to serve HTTP requests, the excess usage is usually via the backend processing/scripting application ( ie: PHP, Ruby, ASP, .NET, Java etc).

Is 80% usage causing a problem? Can you easily add more?

Colin.

two application in ASP.NET
the user are in different country
the concurrency is low

It is slow when save in the database, in addition to sending email and message text

are application that consume SAP information through RFC's

Please indicate what I must do to get this information

1. What sort of Internet connectivity does this server have?
2. Could you provide a full spec list?
3. Along with a snippet of the IIS web log to see how busy the web server is?

0.  Is the IIS Server physical or virtual?
virtual, view attached questio_01
1.  What version of .NET Framework are the applications using?
4.0
2.  How many Application Pools are setup on the web server?
not used Application Pools
3.  Is the database server local or remote?  What is it... MSSQL, Oracle, MySQL, Access, etc.?
remote - Oracle
4.  How are the database server's data and log files configured?
i do not understand
5.  Are there any other applications (other than the web server) that are using the database server?
Where do I verify it?
6.  How many daily users of the apps are there?
10 user. an app saves in database every 30 seconds
7.  Do the applications store session state somewhere?
i do not understand
8.  After an AppPool recycle, how quickly does the app(s) consume RAM?
i do not understand
questio_01.png

#2.   if you have deployed an ASP.NET application in IIS on Server 2012 R2, you must use Application Pools.  There is no way around it.
Microsoft Windows [Version 6.3.9600]
(c) 2013 Microsoft Corporation. All rights reserved.

C:\Windows\system32>C:\WINDOWS\system32\inetsrv\appcmd.exe list apppools
APPPOOL "DefaultAppPool" (MgdVersion:v4.0,MgdMode:Integrated,state:Started)
APPPOOL ".NET v4.5 Classic" (MgdVersion:v4.0,MgdMode:Classic,state:Started)
APPPOOL ".NET v4.5" (MgdVersion:v4.0,MgdMode:Integrated,state:Started)

C:\Windows\system32>C:\WINDOWS\system32\inetsrv\appcmd.exe list sites
SITE "Default Web Site" (id:1,bindings:http/*:80:,state:Started)

C:\Windows\system32>


#6.  How do you know that the app save data every 30 seconds?
tha data save in a database (view column create_date)

view attached
process_task.png

01.png
02.png

I have access to the server by remote desktop to be able to deploy web applications, is there another way to do it?