Оптимизация кода для MKMapView - большое количество аннотаций

В моем приложении есть модальное представление, которое отображает UIMapView. Затем я добавляю большое количество аннотаций (более 800) к этому представлению карты (код ниже).

Проблема в том, что пользователь вынужден ждать около минуты, пока загрузятся все пины. Кроме того, приложение становится медлительным, как только все 800 булавок оказываются на карте.

Может ли кто-нибудь подсказать, как я могу улучшить мой код ниже?

Спасибо.

#import "MapView.h"
#import "MapPlaceObject.h"


@implementation MapView
@synthesize mapViewLink, mapLocations, detail, failedLoad;

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
    // Custom initialization
}
return self;
}

-(void)addPins
{

for (MapPlaceObject * info in mapLocations) {


    double latitude = info.longitude;
    double longitude = info.latitude;

    NSString * name = info.name;
    NSString * addressline = info.addressOne;
    NSString * postcode = info.postCode;

    NSString * addresscomma = [addressline stringByAppendingString:@", "];
    NSString * address = [addresscomma stringByAppendingString:postcode];

    CLLocationCoordinate2D coordinate;
    coordinate.latitude = latitude;
    coordinate.longitude = longitude;
    MyLocation *annotation = [[[MyLocation alloc] initWithName:name address:address coordinate:coordinate] autorelease];


    [mapViewLink addAnnotation:annotation];

}
}

- (void)showLinks : (id)sender {


if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
    detail = [[DetailViewController alloc] initWithNibName:@"DetailViewController-iPad" bundle:nil];
} 

else if (!detail) {

    NSLog(@"Detail is None");

    detail = [[DetailViewController alloc] initWithNibName:@"DetailViewController" bundle:nil]; 

}

int uniqueID = ((UIButton *)sender).tag;

//PlaceObject *info = [mapLocations objectAtIndex:uniqueID];

detail.UniqueID = uniqueID;
detail.hidesBottomBarWhenPushed = YES;

[self.navigationController pushViewController:detail animated:YES];

self.detail = nil;

[detail release];

}

- (MKAnnotationView *) mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>) annotation{

if (annotation == mapView.userLocation){
    return nil; //default to blue dot
}    

MKPinAnnotationView *annView=[[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:@"currentloc"];
annView.pinColor = MKPinAnnotationColorRed;

nameSaved = annotation.title;

for (PlaceObject * info in mapLocations) {

    if (info.name == nameSaved) {

        saveID = info.UniqueID;

    }
}

UIButton *advertButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
advertButton.frame = CGRectMake(0, 0, 23, 23);
advertButton.contentVerticalAlignment = UIControlContentVerticalAlignmentCenter;
advertButton.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter;

[advertButton addTarget:self action:@selector(showLinks:) forControlEvents:UIControlEventTouchUpInside];

advertButton.tag = saveID;

annView.rightCalloutAccessoryView = advertButton;

annView.animatesDrop=TRUE;
annView.canShowCallout = YES;
annView.calloutOffset = CGPointMake(-5, 5);
return annView;

}

- (void)dealloc
{
[mapViewLink release];
[mapLocations release];
[detail release];
self.failedLoad = nil;
[failedLoad release];
[super dealloc];
}

- (void)didReceiveMemoryWarning
{
// Releases the view if it doesn't have a superview.
[super didReceiveMemoryWarning];

// Release any cached data, images, etc that aren't in use.
}

- (void)viewWillAppear:(BOOL)animated {

if (firstTime) {

    CLLocationCoordinate2D zoomLocation;

    zoomLocation.latitude = 51.50801;
    zoomLocation.longitude = -0.12789;

    MKCoordinateRegion viewRegion = MKCoordinateRegionMakeWithDistance(zoomLocation, 15*METERS_PER_MILE, 15*METERS_PER_MILE);

    MKCoordinateRegion adjustedRegion = [mapViewLink regionThatFits:viewRegion];                

    [mapViewLink setRegion:adjustedRegion animated:YES];  

    firstTime = NO;

}    
}

- (void)viewDidLoad
{
[super viewDidLoad];

firstTime = YES;

failedLoad = [[NSMutableArray alloc]init];

self.mapLocations = [BluePlaqueDatabase database].mapInfo;

[self addPins];
}

- (void)viewDidUnload
{
[mapViewLink release];
mapViewLink = nil;
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}