Vastly different results between 2 computers

[samish18]

I get wildly different responses when backtesting on two different devices. They are using the same strategy and data

[NinjaTrader_Jesse]

Hello samish18,

When comparing tests there are some reasons that would cause the strategy to calculate differently. While we would be unable to provide an exact answer of why that is with your custom strategy you can debug the strategy to find out the exact answer. Because every strategy is different there is not one single answer as to why that would be different, that heavily depends on the settings you used and how the strategy was coded.

This guide goes over how to add debugging and then compare results. The short summary is that you add prints into your code and then collect the output after running the strategy in one test then run the second test and collect those prints as well. You can then compare the prints to see how the strategy logically worked in both use cases. Based on your observations you can make any changes needed to have the strategy results become more close to realtime.

https://support.ninjatrader.com/s/article/Developer-Guide-Comparing-Strategy-Results?language=en_US

If you are using the builder you can see the following video for using prints in the builder. https://drive.google.com/file/d/1CCl...gEIwJKv6L/view

[samish18]

If the script is exactly the same, why would it be different? They should be acting on identical data

[NinjaTrader_Jesse]

Hello samish18,

It doesn't matter that the script is the same, it matters that the conditions running the script are the same. You need to debug the use cases to see if they were exactly the same, without knowing that it would be impossible to tell what caused the differences. You can estimate what is causing a different by looking at the chart and executions, to know specifically why would require adding prints to see what happened different.

[TraderTate]

samish18 Did you find your issue? I just purchased a VPS with Ninjatrader 8 for only backtesting purposes. Have the same issue. Same strategy with different results on 2 pc's. The candles on the charts look different as well. Had the same issue on another pc I had in the same house, thought it might be that pc because it was older. Possibly not the older pc now that I am trying a VPS with nothing else running but Ninja for backtesting my strategy. Was trying to alleviate the stress of backtesting on my trading pc. I'll take the strategy results from 1 pc and apply to the other and it's completely different. Even reloaded the historical data. 1 thing I noticed is on my personal pc I can backtest back to July 2023 with a specific Tick chart, on the VPS I can only go back to March 2024.

I'm looking for some tips on what to look for. I'll have to read more about the Prints.