SSD1306 - U8g2lib Framerate?

Thanks so much your reply!

With the F constructor everthing is drawn fine but still not really the speed I want. Is it possible to achieve 25fps on an Arduino with u8g2lib?

This is my current full code:

.h-File:

#ifndef SCRoboDraw_h
#define SCRoboDraw_h

#include "Arduino.h"
#include <U8g2lib.h>

#ifdef U8X8_HAVE_HW_SPI
#include <SPI.h>
#endif
#ifdef U8X8_HAVE_HW_I2C
#include <Wire.h>
#endif

extern U8G2_SSD1306_128X64_NONAME_F_HW_I2C *u8g2;

class SCRoboDraw
{
 public:
    SCRoboDraw();
    void initScreen();
    void draw();
    void drawLine();
 private:
    unsigned long lastFrame = 0;
    int frameRate = 40; // 1000ms/25fps;
    int yPos = 0;
};

#endif

.cpp-File

#include "Arduino.h"
#include "SCRoboDraw.h"

U8G2_SSD1306_128X64_NONAME_F_HW_I2C *u8g2;

SCRoboDraw::SCRoboDraw()
{
}

void SCRoboDraw::initScreen()
{
  u8g2 = new U8G2_SSD1306_128X64_NONAME_F_HW_I2C(U8G2_R0,U8X8_PIN_NONE); 
  u8g2->begin();
}

void SCRoboDraw::draw()
{
  if(millis()-lastFrame >= frameRate)
  {
     lastFrame = millis();
     u8g2->clearBuffer();
     drawLine();
     u8g2->sendBuffer();
  } 
}

void SCRoboDraw::drawLine()
{
  yPos += 1;
  u8g2->drawLine(0,yPos,127,56);
  if(yPos > 64)
  {
    yPos = 0;
  }
}