1 / 14

ATLAS RoI Builder + CDF

ATLAS RoI Builder + CDF. Brief reminder of ATLAS Level 2 Opportunities for CDF (what fits - what doesn't) Timescales (more of what fits and what doesn't). Conclusions from quick tour of ATLAS TDAQ. ATLAS Level 1 looks very much like CDF Level 2

diamond
Download Presentation

ATLAS RoI Builder + CDF

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ATLAS RoI Builder + CDF • Brief reminder of ATLAS Level 2 • Opportunities for CDF (what fits - what doesn't) • Timescales (more of what fits and what doesn't)

  2. Conclusions from quick tour of ATLAS TDAQ • ATLAS Level 1 looks very much like CDF Level 2 • hardware based clustering, energy sums, isolation and muon Pt • Level 1 accept rate for ATLAS is similar to that for CDF (~50-100 kHz) • RoI Builder (RoIB) plus Supervisor processors could act in the same capacity as the alphas do in CDF • same transaction rate (L1A rate) • provided the decision code is simple Supervisors could make the full level 2 decision instead of I/O to LVL2 farm

  3. CDF != ATLAS • Input to RoIB is via S-link • this is different from CDF Run IIa but not different in IIb • Latency in ATLAS Level 2 is enormous • buffers are ~1000 events deep not 4 • RoIB latency is a non-issue for ATLAS • initial prototype of RoIB waited for all event fragments to arrive before sending - this alone would introduce unacceptable latency for CDF it also limits size of L1 RoI data (since this needs to be buffered in the RoIB) • Level 2 decision order is different from the L1A order

  4. Potential CDF Level 2 • Single Builder and input card • 4 processsors • could be more • Output of trigger decisions to PULSAR is probably reasonable, but not necessary

  5. Beginning to look at simulation

  6. Still too infantile but... 40kHz livetime 86% Latency in microseconds

  7. 512k x 32b Memory S-Link Connector 4k x 36b FIFO FPGA GbE MAC LSI L8101 GbE SerDes Agilent HDMP-1636A Opt. Conn. Current Architecture Features • Large input FIFO • Large Buffer • Optical GbEthernet Physical layer • Conforms to S-Link specs • FPGA can do data alteration if needed

  8. ATLAS plan/timescale • The current plan is to produce a prototype early this year (~April) • There is already a 12U prototype (has been for several years) which demonstrated 100kHz operation • 9U prototype system will include the ability (important for CDF but not necessary for ATLAS) of “routing” as opposed to “store and forward” type operation

  9. Conclusions • Appears reasonable to think of RoIB as merging unit for CDF • Still work to do in demonstrating that this idea actually makes sense (same work needed for any other merging scheme) • Next steps should work out dataflow (how much from which sources and including as many of the overheads realistically as possible)

More Related