====== Maximum readout data rate ======


**Question: What is the maximal readout data rate and bandwidth the iGp12 unit can support?**

Internal bus from the IOC to the hardware supports roughly 43(nbsp)MB/s transfer rate. Normally, this high data rate is not exposed to the outside world, with IOC post-processing reducing the 2-D data matrix to a set of vectors (mean, RMS, max RMS record, spectrum).

With Gigabit Ethernet one can actually stream the data out at nearly the full rate. At [[:machines:bessy2|BESSY II]] with 18(nbsp)ms acquisition time (corresponding to 17.2(nbsp)MB data block) Andreas Schälicke has achieved roughly 34.5(nbsp)MB/s average network utilization with 2(nbsp)Hz readout, peaking at 66(nbsp)MB/s Ethernet usage (theoretical maximum for Gigabit Ethernet is 125(nbsp)MB/s).

**Update:** As of IOC revision 2.8 and FPGA gateware 3.11, 2(nbsp)Hz acquisition rate is supported for full SRAM size, 12(nbsp)Msamples. External streaming is limited to slightly shorter blocks of 11.4(nbsp)Msamples.

 --- //[[dim+dokuwiki@dimtel.com|Dmitry Teytelman]] 2013/05/23 10:51//