Backtests extremely slow

[nsymms]

Hi I'm not sure if this has been covered before, but here goes....

Yesterday I loaded a years' worth of tick data for one instrument into NT 7.1000.9 -- it all went well, the data appears to be there. I also had it generate minute and day data while it was importing.

However, now when I run strategy backtests or optimizations, they spend quite a bit of time "loading" data. At least that's what it says on the status window of the control center. I'm trying to test 4 months on a minute-based strategy. Before I loaded all the tick data, it used to take about 10 seconds or less. Now it takes several minutes for the same run.

Is there something I can do to speed this up?

Thanks

[NinjaTrader_RyanM]

Hi nsymms,

First step would be to figure out if the time it takes to load is caused by NinjaTrader downloading the data from your data provider. The only way to prevent it completely from trying to download data is to disconnect when you're making the backtest.

There are many more data points in tick based charts compared to minute, so the time it takes could also be due to processing more data.

[nsymms]

Thanks Ryan for the quick response. Strangely enough, it is actually pulling data from my provider (MBT). My network sniffer shows NT is pulling minute data for the entire testing period. Assuming it's been doing this all along, I have no idea why it's slower now than it was before.

So what's the purpose of me loading all that data into the history center if backtests will pull data from the provider anyway?

Thanks

[NinjaTrader_RyanM]

NinjaTrader loads data from your data provider whenever it determines it could potentially not have all the data pertaining to the requested time period.

You can use the data you imported and prevent NT from downloading by either disconnecting from the data provider, disabling historical data requests for the connection, or by unchecking Get Data from Server under tools > Options > Data tab. .

[nsymms]

Okay, since I trust my imported data, I'll just disconnect whenever I'm doing backtests with that instrument. Of course now the problem is that I'm running the strategy and trying to test it at the same time, so I can't really disconnect... Time to fire up the virtual machine.

edit: Actually, when running backtests, I'll just un-check the "get data from server" in tools->options->data as suggested. No need for all that fancy virtual technology.

Thanks again

[nsymms]

Just for anyone who may be reading this thread in the future...

What finally fixed this issue for me was running "Repair DB" from the Tools->Options->Data dialog. Evidently all that fiddling around with imports and such must have messed up the database. The "Repair" option solved my problem -- no more slowness, no more trying to fetch data from my provider during backtests.