What are the ping values ​​between servers within the same data center?

Question

linux

Ping here refers to the time required for a signal to overcome the "space" between servers in one direction . Protocol: UDP, TCP
1. If you order several servers in one data center, what is the value of ping between these servers? 1, 10, 25, 50, 100, 150, 250ms?
2. Building a "private network", which providers offer, should improve the indicator (that is, reduce ping)?
3. How stable is this ping?
4. What does it depend on? How to reduce?

Answer 1

1) 1ms or less.
2) what is meant by a "private" network? Separate Vlan? It will not increase in any way
3) Stable up to critical load indicators of network equipment
4) Depends on the network equipment, how many switches a packet needs to go through on the way from the sender to the recipient. The minimum ping values ​​will be when the servers are located in the same rack, connected to the same switch, having the same network. But the difference can be minimal or just not noticeable from servers connected in different racks, having different networks, having 3-4 switches and a router in the interval.

Answer 2

Almost all questions should be asked to each hoster separately.
DCs are different, pings too.
We have 3 servers nearby, they asked specifically nearby to be given.
Ping ~0.1ms
Without any private networks and dancing with a tambourine.