c# – 最快的阵列初始化？

该数组包含超过一千个项目,当首次使用该类型时,我的程序经历了严重的减速.我想知道是否有办法在C#中快速初始化大型数组.

public static class XSampa {
    public class XSampaPair : IComparable<XSampaPair> {
        public XSampaPair GetReverse() {
            return new XSampaPair(Key,Target);
        }
        public string Key { get; private set; }
        public string Target { get; private set; }
        internal XSampaPair(string key,string target) {
            Key = key;
            Target = target;
        }
        public int CompareTo(XSampaPair other) {
            if (other == null)
                throw new ArgumentNullException("other","Cannot compare with Null.");
            if (Key == null)
                throw new NullReferenceException("Key is null!");
            if (other.Key == null)
                throw new NullReferenceException("Key is null!");
            if (Key.Length == other.Key.Length)
                return string.Compare(Key,other.Key,StringComparison.InvariantCulture);
            return other.Key.Length - other.Key;
        }
    }    
    private static readonly XSampaPair[] pairs,reversedPairs;
    public static string ParseXSampaToIpa(this string xsampa) {
        // Parsing code here...
    }
    public static string ParseIpaToXSampa(this string ipa) {
        // reverse code here...
    }
    static XSampa() {
        pairs = new [] {
            new XSampaPair("a","u0061"),new XSampaPair("b","u0062"),new XSampaPair("b_<","u0253"),new XSampaPair("c","u0063"),// And many more pairs initialized here...
        };
        var temp = pairs.Select(x => x.GetReversed());
        reversedPairs = temp.ToArray();
        Array.Sort(pairs);
        Array.Sort(reversedPairs);
    }
}

PS：我使用数组将X-SAMPA语音转录转换为带有相应IPA字符的Unicode字符串.