How can I add text （numbering information） for each scatter point which plotted by ScatterPlotItem with the least waste time

[zty1122zty]

I use pyqtgraph.ScatterPlotItem to draw about 256 scatters with 3ms.Also, I want to add text (number,such as 1,5,...,60,...) for each scatter point. I tried some methods to do that. But every method must use “for” loop, this waste lots of time--about 90ms for 256 textitems. I also tried keyword "tip" of ScatterPlotItem, but it is not a useful and intuitional method.
Could anyone give me some advice or thinking to display 256 textitems with about 50ms or less? Thanks!