TPP1000 Step Response Differs on Different Probes

Why do some of my TPP1000s show different step response from other ones in the same box?

Specifically I have tested these Serial Numbers:
C169xxx, C185xxx, C196xxx

All of those probes pass our specifications. Step response within 50ns can vary +-5% based on the batch of wafers that went into the construction of the probes.

Probes created in the same batch from the same wafers have more similar performance than probes created 27,000 units apart (as in C169000 to C196000).

One additional comment - please be sure that each probe is compensated on the channel is it is being used on.  The probe compensation is stored separately on each channel (it is not stored in the probe).  You can double-check the probe's compensation status on the channel it is connected to in the channel badge > Probe panel.