Hello! I'm new to this forum! Since the IO is within the Xeon E5 series CPU itself... I was wondering if a faster CPU means faster IO as well?
Yes and no.
1. There are two different lines of Intel Xeon E5 CPUs. The E5-1400/2400 lines fit Socket 1356 and has three memory channels and 24 lanes of PCIe 3.0. The E5-1600/2600/4600 lines fit Socket 2011, have four memory channels, and have 40 lanes of PCIe 3.0 I/O.
2. The number of PCIe lanes varies by socket- LGA1356 units have 24 lanes and LGA2011 units have 40. All of the chips on the same socket have the same number of active lanes and they all work at PCIe 3.0 speeds.
3. The memory controller speed varies with the particular chip's price more than anything. Lower-priced "value" models have memory controllers running at DDR3-1066 maximum, "standard" models can use DDR3-1333, and "performance" models can use DDR3-1600. Chips with more cores generally cost more and thus are allowed to run their memory controllers at higher speeds. You need to look at an Intel reference such as ark.intel.com to see exactly how fast any particular chips' IMC runs.
4. The chip-to-chip QPI link speeds vary with chip price as well, similarly to the IMC speed. You will also need to consult an Intel reference to determine how fast your QPI links run on your particular chip.
5. Whether or not faster I/O buses will really help your computer's performance is very much application-dependent.