Despite his success in Spain, Pepe criticised the Real fans in an interview with BeIN Sports Turkey.
"Perhaps Real Madrid fans won't like me saying this but they say Real Madrid fans transmit enthusiasm but I don't think they do. That's not the reality," 34-year-old Pepe said on Monday.
"The Besiktas fans are very passionate. When you go out onto the pitch the noise coming from the stands always hits you."
The deafening atmosphere at Besiktas's Vodafone Arena hit the headlines in September when RB Leipzig forward Timo Werner asked to be substituted during their 2-0 Champions League defeat, with the German club saying the player was suffering from circulatory problems and dizziness from the noise.
"The atmosphere at Besiktas is very different to at Real Madrid. In Turkey people really love sport, they only think about football," added Pepe. "After games, we can hear the noise of the supporters until the early hours of the morning."
Real have had a difficult first campaign since Pepe's departure, suffering back-to-back defeats to Liga debutants Girona and Tottenham Hotspur in the Champions League last week and are third in the domestic standings, eight points adrift of leaders Barcelona and four behind Valencia.
After a resounding 3-1 defeat away to Tottenham, Cristiano Ronaldo said the team missed the presence of recently departed players such as Pepe, James Rodriguez and Alvaro Morata.
Real beat Las Palmas 3-0 on Sunday but the fans turned on out-of-form striker Karim Benzema when he was substituted in the second half, booing the Frenchman off the pitch.
Pepe gained infamy in his second campaign in Spain for kicking out at Getafe's Javier Casquero after fouling him and punching Juan Albin in a game in April 2009, earning a 10-game ban, and later said he had "lost control".
He was sent off four times for Real, including for a lunge on Barca's Dani Alves in a Champions League semi-final, first leg in 2011 but was fondly remembered by fans for his spirited performances and consistent partnership with Sergio Ramos.
(Reporting by Richard Martin in Barcelona; Editing by Ken Ferris)
