Here are the reasons not to use 10G BaseT. Depending on the size of the customer you are working with, some of these arguments may gain better traction than others.
- Power Consumption
The first thing to point out is that the capital cost will be lower but the operational costs will be higher because of power consumption. Not everyone has 10K ports in their environments, but below is an illustration of the concept of power savings. The cost savings is highest with between 1-10K ports.
- Application Latency
Low latency is critical to ensuring fast response time and reducing CPU idle cycles; therefore, increasing data center efficiency and ROI. Depending on the number of hops, the latency can get pretty severe in comparison. The below graph is in microseconds and illustrates the difference.
- Cable Length
Distance is an issue which brings us to reason #4
- ANEXT/Alien Crosstalk/Interference
10G BaseT is more vulnerable to interference and choice of high quality cabling is paramount to minimize interference.
So to summarize, 10GBaseT is for Admins who don’t care about excellent application latency and CPU performance or the long term power costs of operating their equipment. Using 10GBaseT increases power consumption and increases energy costs for everyone. It is simply not the green option. If every data center in the world used 10GBaseT instead of 10G SFP+, the math on that equals a mind boggling amount of additional power consumption.
The other side of this argument which is what you may be more interested in is much simpler. Lower cost and complexity. The application and power performance is fractional in an SMB environment and your end users will never see the difference. Unless operational expenses hit their budget, then why not spend the money elsewhere.