Timing Kit for 10G-PCIE3-8D-Q Network Adapter
A timing kit is available for CSPi’s Myricom® 10G-PCIE3-8D network adapters. Myricom network adapters provide timestamps with every packet, even on transmit (a unique feature). The accuracy of these timestamps is very good. Adding the optional timing kit enables connection of even more accurate external oscillators and GPS devices. A GPS also offers legally traceable time for compliance applications.
The TCXO oscillator that ships installed on 10G-PCIE3-8D adapters is significantly better than the oscillator found on a server’s motherboard. It has high frequency stability over modest periods of time.
Myricom DBL™ software uses timestamps to measure “tick to trade” latency in nanoseconds. Using the on-board TCXO, latencies measured at various times in a single day are accurate to 61 bits (ignore the last three bits of the 64-bit value). Connecting an external oscillator to the adapter can increase this to 62 bits and extend the time elapsed between readings from “single day” to longer periods (better oscillator aging). Connecting a GPS enables mixing timestamps captured on multiple adapters in multiple datacenters.
Automatic Oscillator Trimming
When provided with an external timing reference, an FPGA on the Myricom 10G-PCIE3-8D network adapters will arithmetically “trim” the onboard oscillator into synchronization. This feature, typically associated with adapters listing for $10,000 or more, is standard on the more competively priced Myricom adapter.
Oscillator trimming does not require the optional timing kit as you can trim against the host server’s time-of-day clock. This might be done if the host synchronizes time with a external time source, such as an IEEE-1588 Grandmaster.
Enabled by Timing Kit
The optional timing kit allows customers to attach their own GPS and/or atomic clock to the network adapter for the highest accuracies in the industry.
- Adapters without this kit use CSPI’s on-board TCXO clock which is significantly better than clocks found on server motherboards
- Connect an OCXO or rubidium 10 MHz clock to remove the short-term jitter from a datacenter’s IEEE-1588 grandmaster signal
- The best latency measurement is acheived with a stand-alone rubidium clock, keeping multiple adapter timestamps synchronized to within ±3 nanoseconds
- Connecting a GPS allows for the comparison of time stamps captured on multiple adapters in multiple datacenters