In a linked list (the tail node is introduced for performance purpose only)

Edit

Please read the comments to this answer. People claim I did not do proper tests. I agree this should not be an accepted answer. As I was learning I did some tests and felt like sharing them.

Original answer...

I found interesting results:

// Temporary class to show the example class Temp { public decimal A, B, C, D; public Temp[decimal a, decimal b, decimal c, decimal d] { A = a; B = b; C = c; D = d; } }

Linked list [3.9 seconds]

LinkedList list = new LinkedList[]; for [var i = 0; i < 12345678; i++] { var a = new Temp[i, i, i, i]; list.AddLast[a]; } decimal sum = 0; foreach [var item in list] sum += item.A;

List [2.4 seconds]

List list = new List[]; // 2.4 seconds for [var i = 0; i < 12345678; i++] { var a = new Temp[i, i, i, i]; list.Add[a]; } decimal sum = 0; foreach [var item in list] sum += item.A;

Even if you only access data essentially it is much slower!! I say never use a linkedList.

Here is another comparison performing a lot of inserts [we plan on inserting an item at the middle of the list]

Linked List [51 seconds]

LinkedList list = new LinkedList[]; for [var i = 0; i < 123456; i++] { var a = new Temp[i, i, i, i]; list.AddLast[a]; var curNode = list.First; for [var k = 0; k < i/2; k++] // In order to insert a node at the middle of the list we need to find it curNode = curNode.Next; list.AddAfter[curNode, a]; // Insert it after } decimal sum = 0; foreach [var item in list] sum += item.A;

List [7.26 seconds]

List list = new List[]; for [var i = 0; i < 123456; i++] { var a = new Temp[i, i, i, i]; list.Insert[i / 2, a]; } decimal sum = 0; foreach [var item in list] sum += item.A;

Linked List having reference of location where to insert [.04 seconds]

list.AddLast[new Temp[1,1,1,1]]; var referenceNode = list.First; for [var i = 0; i < 123456; i++] { var a = new Temp[i, i, i, i]; list.AddLast[a]; list.AddBefore[referenceNode, a]; } decimal sum = 0; foreach [var item in list] sum += item.A;

So only if you plan on inserting several items and you also somewhere have the reference of where you plan to insert the item then use a linked list. Just because you have to insert a lot of items it does not make it faster because searching the location where you will like to insert it takes time.