Hi. I have a problem with timing . I have a impact twin sound card and roland di midi keyboard. I am playing over  prepared audio loops . but my midi sound (nexus)  little early playing. so sorry for my bad english. timing problem . not latency . early play. why I dont understand . if you help me I am be so happy. Normal my record have to  start 14.01 but it is starting 13.50 etc. I am playing of course normal . I have a good music ear ) 
I thank you for taking the time to read this and would appreciate any help or comments you could offer.
 
 
 
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Turn on Input Quantize in the Track Inspector

I've had this issue also.  I had to switch to WDM drivers and REDUCE the latency, even though I wasn't using audio.  If you search around the forums, you'll the post i found that explains this.  It makes no sense, but it should work.
 
Alternatively, you could probably switch to MIDI-controlled metronome and assign it to your drum channel, but you might end up with the same problem.

Thank you very much . I will try  . I think there is latency  in hearing. playing music  loop latency. my midi keyboard play sound (vst) is reconding little early . Thank you very much Bristol Jonesey  And Gargamel314 .

This is what happens when you don't have a good quality audio driver. Just quantize the tracks. 
The midi driver is always MME. Some keyboards come with a USB midi driver, like Roland and Yamaha. Those perform better than generic midi drivers. So see if your Roland has a driver. 
But if the Audio driver gives Sonar the wrong calculations, your timing offset will be wrong, this is normally late but can also be early. It's playing back your audio a little too soon. 
ASIO drivers are he only drivers that seem to get the timing bang on. So if your sound card has ASIO use it. 
You only other option is to use Asio4all. But a proper USB audio interface is the best solution. 
 

what is the best ? I  connected my midi with usb to computer. But I can connect my midi keybord to my TC impact twin sound card . I am using ASIO4 all and using last impact twin driver. My computer  found  midi driver from internet automaticly   thank you Cactus music 

http://www.tcelectronic.com/impact-twin/support/
https://www.roland.com/global/support/by_product/juno-di/
Not sure if these are the exact models so double check. 
 
 
You should always use the drivers direct from product support web page, do not use windows generic drivers or asio4all unless there are no drivers available. Download and install the correct drivers and I bet it will solve your issue. 

I did not face such kind of issue so for. I learn about this issue here.