SURF slower than SIFT

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Hi everyone, I'm testing the performance of opencv feature detection and description algorithms and even though the paper claims otherwise, Surf works slower than Sift by about a milisecond or two. I couldn't make sense of it. I changed the cvRound input to float as suggested here, but it doesn't do anything. My code is below, there are also other detectors and descriptors there and I uncomment whichever I'd like to test, I'd appreciate anyone who can shed light on this, they both match around 600-700 keypoints:

//// DETECTION
    //OrbFeatureDetector detector(500);
    SurfFeatureDetector detector(1500,4);
    ////cv::FAST(imgB, keypointsB, 20);
    //SiftFeatureDetector detector;


    // DESCRIPTOR ORB, SURF, BRIEF, SIFT. Uncomment these lines if you want to use SURF, ORB, BRIEF or SIFT.
    //OrbDescriptorExtractor extractor;
    SurfDescriptorExtractor extractor;
    //BriefDescriptorExtractor extractor;
    //SiftDescriptorExtractor extractor;

        // detect
    double t11 = (double)getTickCount();
    detector.detect( img1, keypointsB );
    t11 = ((double)getTickCount() - t11)/getTickFrequency();

    double t1 = (double)getTickCount();
    detector.detect( img2, keypointsA );
    t1 = ((double)getTickCount() - t1)/getTickFrequency();

    double t22 = (double)getTickCount();
    extractor.compute( img1, keypointsB, descriptorsB);
    t22 = ((double)getTickCount() - t22)/getTickFrequency();

        // extract
    double t2 = (double)getTickCount();
    extractor.compute( img2, keypointsA, descriptorsA);
    t2 = ((double)getTickCount() - t2)/getTickFrequency();


    // match
    double t3 = (double)getTickCount();
    matcher.match(descriptorsA, descriptorsB, matches);
    t3 = ((double)getTickCount() - t3)/getTickFrequency();
    //std::cout << "matching time [s]: " << t3 << std::endl;