Flow Control and Buffer settings on NIC

[BitMaster]

!!! This is very technical and I dont want the average user to go and fumble with the branch you sit on :) Read twice before you work on your network if you are unsure what you do !!!

 

 

 

I just stumpled across an article referring to general latency and priority settings in regards to old/modern CPU's and switches etc...

 

baseline is that the author of the article advises to set FlowControl completely to OFF and Buffers both Tx/Rx to its smallest value on modern PC's ( Pentium III or better CPU )

 

This is said to speed up Networking and minimize latency further than any other measures.

 

 

Reason to disable FlowControl: it's made for LARGE networks with switches and routers that support FlowControl and have it configured as well. It can only harm you in smaller networks

and may even be the cause for some bad latency in single/low-core-count core CPU's

 

Same reason applies to Buffers, Tx/Rx: Old CPU's needed that buffer, PentiumII and older mostly. Since PIII any Gigabit is well driven without large Buffers. In fact, the smaller the buffer the faster your super-multi-core CPU can have the data and process it. Unless you have a 10Gbit NIC + switch + 2nd PC with 10Gbit you should not enable it, but use it at 10Gbit and faster only.

 

 

What really pays, IMHO, is a true Intel network adapter, not Realtek, not Killer, not anything else( unless SRV grade quality ). If you own such a card, read about TOE ( TCP Offload Engine, also called TCP Chimney Offload )

 

 

just some info if you look for optimizing networks ..OR..need to find the culprit for high latency on some network cards.

 

 

*EDIT:

My values for the onboard Intel 1000 Pro were 256Tx and 512RX, now both to lowest value which is 80. Flowcontrol set to OFF as well. Will see if it really speeds up things or if it breaks anything...LoL

Edited September 16, 2016 by BitMaster