Not an exact answer but I did a split 10 gallon batch of Helles with 34/70 and 2124 since I didn't have enough time to build up a starter big enough to do the whole batch with 2124. End result was that I could tell a difference between the two, the 2124 seemed to clear faster but once they both has sufficient lager time I couldn't tell which batch was done with which yeast. Though they are supposed to be about the same I've never tried 830 and 2124 side by side.