In the Rackspace overview for their next gen servers they have a table of flavor options.
In the table there is a column called RXTX factor with no explanation. I tried googling, but couldn't find anything definitive (something to do with receiving and transmitting?). It looks like it goes up with the bigger servers, so I'm guessing the higher the better. Could someone enlighten me?
After contacting support, this is the answer they gave:
RXTX Factor
Aggregate outbound bandwidth, in megabits per second, across all attached network interfaces (PublicNet, ServiceNet, and Cloud Networks). Outbound public Internet bandwidth can be up to 40% of the aggregate limit. Host networking is redundant, and bandwidth is delivered over two separate bonded interfaces, each able to carry 50% of the aggregate limit. We recommend using multiple Layer 4 connections to maximize throughput. Inbound traffic is not limited.
Picking an example: first row 512MB standard instance, RXTX factor 80.00/mbs is the maximum speed across all the network interfaces (public, private, cloud network) that data can leave the server
The first paragraph of this can be found in their docs
This seems like a bit of a twisting of what RXTX factor intuitively should mean and is not a ratio but actually in Mb/s.
It's far from clear but I'm reasonably certain that it's the ratio of how much bandwidth there is available for both receiving and transmitting. For instance a machine with no limitations would have a RXTX factor of 100, whereas a machine that could only receive half of what it could transmit would be 200. Basically it's just rate-limiting on the network and their quite-hard-to-follow arse/ass-covering weasel-wording :)
