I have a SortedDictionary 

```
 SortedDictionary<int, CPUOptimizationObject> myDict;

```

Now I want to find the first value above X.
I can do something like this 

```
foreach (var iKey in MyDict.Keys)
{
   if (iKey >= thresholdKey)
   {
       foundKey = iKey;
       break;
   }
}

```

but this isn't good performance wise.  

Any better suggestion?  

(is there a method for that in the collections something like Binary search for SortedDictionary ?)