MKRZero DAC is too slow

[engrhyt]

Hi there, I am in trouble now and very need help in hurry.
Output from DAC is so slow about 2Hz sinewave no delay is added.
I agree to have silent gap between complete sine cycle for computational task.
However, I want 33Hz or 337 Hz (if possible) sine wave.

 void setup() {
  AdcBooster();
  Serial.begin(9600);
  analogWriteResolution(10);
  analogReadResolution(12);
  analogReference(AR_EXTERNAL);
} 

void loop() {
  
  int AA1[512];
  int AA2[512];
  int AA3[512];
  int AA4[512];
  int valueout;
  int count =0;

for (int i=0; i<=2047; i=i+4){
    valueout=512+(int)512*sin((float)i*3.14159/1024);
    analogWrite(A0, valueout);
   AA1[count]=analogRead(A1);
   AA2[count]=analogRead(A2);
   AA3[count]=analogRead(A3);
   AA4[count]=analogRead(A4);
   count=count+1;
  }
} 

My system is running good with nano 33 BLE.
However, it damaged and has not come yet.
I have to use MKR ZERO. yes it more lower noise and has DAC.
Very compact for my application.

I know ADC is slow so I use booster code from this forum
speeding up analogread() at the Arduino Zero - Hardware / Arduino Zero - Arduino Forum

 void AdcBooster()
{
  ADC->CTRLA.bit.ENABLE = 0;                     // Disable ADC
  while( ADC->STATUS.bit.SYNCBUSY == 1 );        // Wait for synchronization
  ADC->CTRLB.reg = ADC_CTRLB_PRESCALER_DIV32 |   // Divide Clock by 64.
                   ADC_CTRLB_RESSEL_12BIT;       // Result on 12 bits
  ADC->AVGCTRL.reg = ADC_AVGCTRL_SAMPLENUM_1 |   // 1 sample
                     ADC_AVGCTRL_ADJRES(0x00ul); // Adjusting result by 0
  ADC->SAMPCTRL.reg = 0x00;                      // Sampling Time Length = 0
  ADC->CTRLA.bit.ENABLE = 1;                     // Enable ADC
  while( ADC->STATUS.bit.SYNCBUSY == 1 );        // Wait for synchronization
} 

Thank you in advance,

E.M.