USCIS runs in its own pace. I applied through EB1 category and both I-140 and I-485 together. It took 10 months to approve I-140. I had my greencard after 22 months of filing the applications.

But, a friend of mine had everything within 2 months of applying in EB1 category. And both these cases were sent in Texas. Bottom line is: USCIS is unpredictible.