L2ßeta: Current Focus

B. Hirosky Jan 5 ‘01

L2ßeta: Current Focus Last Friday’s 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)


Summary of Hardware findings

CPU boards:

SINGLE->QUAD Power PC Variety

SINGLE->DUAL PIII Variety

I/O CARDS:

PMC CARDS w/ Internal FIFO/MEMORYCatalina (64 bits wide at 33MHz)S-link (32 bits wids at 33 MHz)Transtech (64 bits wide at 66 MHz) NEW FIND!


DUAL/QUAD Power PC OptionSingle/Dual/Quad PPC 750 450 MHZ PPC 7400 to come30% faster than alpha in INTs

about the same in fp


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


A Dual Pentium III Option Dual 1GHz PIII

specint95 46.6 vs alpha 15.4


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 - can’t replace a whole crate•Maybe single vendor for the dual PIII board, many for singles


Catalina QC64-PMC


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 FIFO’s on our adapter card•Should be able to get LINUX drivers

Con:•Runs only at PCI 33MHz, same as we have now•It’s a one way card, need another PMC card for output


CERN S-link to PMC, PMC to S-link

Output Card

Input Card


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


Transtech-DSP PMC-FPGA I/O card


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•It’s a two-way card•Choice of onboard FPGA•Lots of fast on board SRAM (can it replace fifo’s)•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


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...

L2ßeta: Current Focus

Documents

Transcript of L2ßeta: Current Focus