L2eta: Current Focus

1
L2ßeta Current Focus

• Last Fridays meeting at UMD
• Bob Hirosky, Drew Baden, Rob Bard, John Giganti
• Discussed details of various SBC and I/O card
  options
• Re-iterated desire for simple, off-the-shelf
  re-implementation
• More detailed discussions of hardware
  requirements
• Discussion of ß-2-ß PIO reduction for
  multiprocessor models
• AGP-style solutions set aside - leverage
  existing PCI experience for minimum development
  time
• Prime contenders include
• SBCs single or dual PIIIs dual or
  quad G4s
• I/O (modified) s-link PMC(s) Catalina
  64bit PMC
• or similar (Transtech)
  

(vs redesign)
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Summary of Hardware findings
CPU boards SINGLE-gtQUAD Power PC
Variety SINGLE-gtDUAL PIII Variety I/O
CARDS PMC CARDS w/ Internal FIFO/MEMORY Catalin
a (64 bits wide at 33MHz) S-link (32 bits wids
at 33 MHz) Transtech (64 bits wide at 66 MHz)
NEW FIND!
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Single/Dual/Quad PPC 750 450 MHZ PPC 7400
to come
DUAL/QUAD Power PC Option
30 faster than alpha in INTs about the same in fp
4

• Power PC option comments cost
  8K(dual)/14K(quad)
• Pro
• Quad CPU board can replace a whole crate, no need
  to alpha-alpha PIO - use shared memory instead
• 2 PMC slots are on completely separate busses -
  limits bus latency
• 64bits/66MHz - higher bandwidth for DMA
• 32bits/33MHz - lower bandwidth for other things
• Con
• Longer startup curve due to switch to PowerPC
  linux?
• Compiler options under Linux? Linux compatible
  images?
• Single vendor for this QUAD board, several for
  single/duals

5
A Dual Pentium III Option
Dual 1GHz PIII
specint95 46.6
vs alpha 15.4
6

• PIII option comments
• Pro
• Huge amounts of CPU now on the shelf
• More familiar Linux
• KAI compiler under Linux
• Con
• PCI bus is only 32bits/33MHz - would have to live
  w/ estimated 65MB/s Max bandwidth (vs 80 ish now)
• No QUAD option yet - cant replace a whole crate
• Maybe single vendor for the dual PIII board, many
  for singles

7
Catalina QC64-PMC
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• Catalina PMC card comments cost 4.5K
• Pro
• 64 bits wide w/ user programmability in onboard
  FPGA
• FPGA programmable from PCI bus!
• Lots of FIFO space on board, we could do w/o
  FIFOs on our adapter card
• Should be able to get LINUX drivers
• Con
• Runs only at PCI 33MHz, same as we have now
• Its a one way card, need another PMC card for
  output

9
CERN S-link to PMC, PMC to S-link
Input Card
Output Card
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• S-link PMC card comments
• Pro
• Lots of support from CERN/LHC
• We could use this as a base design if we later
  build PMC cards ourselves
• Con
• Runs only at PCI 33MHz / 32 bits
• way cards, use two of them or modify an existing
  design

11
Transtech-DSP PMC-FPGA I/O card
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• Transtech PMC card comments cost 2.5-5K,
  depending on FPGA
• Pro
• 64 bits wide w/ user programmability in onboard
  FPGA
• 66 MHZ PCI interface
• Its a two-way card
• Choice of onboard FPGA
• Lots of fast on board SRAM (can it replace
  fifos)
• Promise of LINUX drivers
• This company is working w/ DNA computers
• Con
• FPGA programming might be a bit more difficult if
  we use the onboard memory to implement or FIFOs
• Not delivered yet (but promise several week time
  scale - this board is a modification of an
  existing DSP board, not made from scratch)

Newest find - need to do more research on this
one, but it looks promising
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SYSTEM OPTIONS
QUAD PowerPC Catalina card output PMC QUAD
PowerPC Transtech card ?Fastest I/O ?option
of removing alpha-alpha PIO ?separate PCI
buses, may make this a non-issue ?
Linux/Compiler issues ? Less certain about
future enhancements to SBC PIII S-link
Card ? Compilers / Familiar Linux ? Maximum
symmetry w/ existing system ? 18-25 PCI BW hit,
65MB/s max (MBdma needs 20MB/s)
Continuing work on draft TDR for mid Feb...