Make sure that your clock source is stable before you take it out on your poor brute
My clock is, within reason (give or take some samples), stable.
I've mentioned this before but here I go again: computers do not generate a stable midi clock generally speaking. All the other computer processes take priority and skew the clock output.
To properly sync all your gear, you need a guarantee clock source either via a dedicated clock, or some type of clock converter. I personally use Expert sleepers USAMO and it works very well to set my clock through out my studio. The only downside to the USAMO is that it uses up an audio output on your interface, but it is laser accurate.
Please keep in mind: the above mentioned will remedy your jitter, you will still have your system's inherent latency which must be delt with separately.
Hope this helps, good luck.