Atheros AR956x (ASUS Z-87 Pro) Wireless settings (Receive/Transmit Buffers)

[FireFish]

Hi

I'm interested to know from a performance point of view (rather than memory & cpu) changing the receive & transmit buffer sizes would have on performance.

I'm particularly interested in optimizing my connection for streaming and fast paced online gaming. I'm assuming lowering the buffer would be better?

Default values are 512 Transmit and 256 Receive.

Thanks!

 

[bill001g]

In theory it will in practice it likely will have no effect or cause packet loss.

Pretty much the buffers are to hold data that is burst into the interface from the CPU. This would normally imply you were doing more than just running a game or streaming. Both those applications send data at a very regular rate. So avoiding running other data intensive stuff at the same time would reduce the need for these buffers.

This is serialization delay. on a gig port a max mtu packet of 1500 bytes will only take .012ms to transmit. so you could send 100 of these maximum size buffers and only add 1ms of delay. If it would for any reason run out of buffers it will drop any new traffic coming in.

Inbound buffers are somewhat more rare. They imply the processor is too busy to accept the data. Again if you reduce the size you may reduce the delay but you will now take loss rather than delay.

The delay is so tiny it likely makes no difference in any real world application. Yes you can measure it will special tools but it is likely undetectable by a person.

 

[FireFish]

In theory it will in practice it likely will have no effect or cause packet loss.

Pretty much the buffers are to hold data that is burst into the interface from the CPU. This would normally imply you were doing more than just running a game or streaming. Both those applications send data at a very regular rate. So avoiding running other data intensive stuff at the same time would reduce the need for these buffers.

This is serialization delay. on a gig port a max mtu packet of 1500 bytes will only take .012ms to transmit. so you could send 100 of these maximum size buffers and only add 1ms of delay. If it would for any reason run out of buffers it will drop any new traffic coming in.

Inbound buffers are somewhat more rare. They imply the processor is too busy to accept the data. Again if you reduce the size you may reduce the delay but you will now take loss rather than delay.

The delay is so tiny it likely makes no difference in any real world application. Yes you can measure it will special tools but it is likely undetectable by a person.

This is incredibly useful and really helps my understanding. I particularly appreciate the information on the time/latency! For some reason I was under the impression that the buffer would be full at any given point and only send/receive when full, thus be a perminant increase to latency - thanks again for sharing your knowledge and clearing that up.