The easy way to solve this would be to check the max values, and see if there are 2 values which are identical, instead of drawing a marker for each, draw on marker, and concatanate the label for those two into on string, ie. "RAM1 & RAM2" for the label.

Wouldn't solve the case where the sizes are so close they almost overlap.
It also okay, not to handle, the issues with max values that are so close above each other that the labels overlap.