Hello, Greetings.
Assumption - It is high traffic blog
Factor 1 : Type of content
You have written post which as 1 Image; size = 200KB
Total page size = 250KB
It takes around 1 second to load 1 blog post
capacity = 4MB per 1 second
You can serve 16 concurrent visitors per second i.e. up-to 960 visitors per minute
Factor 2 : Setup
How well you have setup and optimised server and it's components performance.
same amount of resources [CPU, RAM] can serve maximum 10 concurrent visitors or 1000 concurrent visitors depending upon performance tuning.
Factor 3 : Quality vs Quantity
Intel Xeon E3-1230 2.2 GHz = Intel Xeon E5-2660 2.2 GHz?
Yes; In numbers of GHz they might look equal; real difference seen when they put through tests.
Same goes for rest of hardware and network.
Factor 4 : location
Which Geo location you are about to target; Is your server reside at same location?
or Making use of CDN services.
Since we are talking about speed of network; You should pay attention to How far data being travelled before reaching users screen! There are several tests to get better Idea such as Network Ping Test. Lower Ping = Faster Delivery.
Factor 5 : Hosted Data
Make sure than, hosted data is clean and your system meets the requirements [Error free]; It greatly affects application response time.
Factor 6 : Cache
You can utilise Object cache to decrease server load such as Redis / Memcache [Database Quarries].
You can utilise OPcache, and several mechanism to decrease CPU, RAM usage and enhance ability to serve visitors.
Dear, With given limited information; we can only guide you to figure out rest of the things.
First you have figure out requirements of application which would be hosted; how many concurrent visitors would be expected; on that basis you can decide whether the 4Mbps is enough or not.
Regards