This was originally published in June of 2008 at 10GbE.net.
For those not into style Manolo Blahnik is one of the leading female shoe designers, and often Blahnik’s start at $700/pair, the price of a good 10GbE NIC. As most servers have moved to dual socket quad-core processors the value proposition for TCP Offload Engine (TOE) 10GbE NICs has quickly eroded.
In the spring of 2006, a good non-TOE 10GbE NIC consumed 40% of the host CPU in a dual-socket dual-core server and provided >6Gbps of performance, while a similar TOE did the same job using only 10% of the host CPU. So with a 30% savings in host CPU, there was some value in using a TOE. With two years of improvements in silicon, stateless offloads, and servers moving to dual-socket quad cores we now have 10GbE NICs capable of near-wire rate (>9.5Gbps) that consume only 10% of the host CPU. Similarly, TOE NICs in the same environment consume roughly 5% of the host CPU.
By most estimates, servers are typically running at 20% CPU utilization, as a result of application load. So will a 5% savings in host CPU be noticed, let alone worth the added purchase price of a TOE? No. Add to that the Linux Foundation’s 14-point argument against using TOES
, written by the Linux Kernel developers themselves, and one would wonder why people still consider TOEs in style.
Here are the 14 reasons cited by the Linux Foundation on their
- Security updates
- Point-in-time solution
- Different network behavior
- Hardware-specific limits
- Resource-based denial-of-service attacks
- RFC compliance
- Linux features
- Requires vendor-specific tools
- Poor user support
- Short term kernel maintenance
- Long term user support
- Long term kernel maintenance
- Eliminates global system view
If you are seriously interested in buying a TOE you should read their TOE page.