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P3K RTC Status

P3K RTC Status

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P3K RTC Status

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  1. P3K RTC Status Tuan Truong & Mitchell Troy P3K Team Meeting #4 7/19/2007

  2. P3K RTC Requirements • CCD50 will be used in the HOWFS • 128x128 pixels, split frame (top and bottom half) with 8 vertical readouts per half for a total of 16 readouts • At 2.5Mpixels/sec 128x128 pixels SciMeasure has achieved 2018Hz, 9.8e- read noise • At 2.5Mpixels/sec 64x64 pixels with 2x2 binning SciMeasure has achived 4973Hz with 9.3e- read noise • Requirements • Not yet defined in detail • Plan to develop one page requirements ASAP • Compute latency: DM commands sent 250us after last pixel received when running at 2KHz with 128x128 pixels • DM command latency is 98us • Total Latency= int_time/2+read time + compute time + DM command time • Total Latency (us) = 500/2 + 500 + 250 + 98 = 1098us • The baseline reconstruction algorithm is a vector matrix multiply for all 3368 active actuators.

  3. Analog TigerSharc TS201 600MHz DSP Timing derived from DSP specs sheet. 3368 actuators. 3368 subapertures. 8 octal-DSP boards (for a total of 64 DSPs). Total compute latency: 428 us. Centroid: 6 us. VMM: 301 us. Sum: 101 us. Servo: 20 us. NVIDIA GeForce 8800 GTX GPU Timing measured on real GPU hardware. 3456 actuators (multiple of 64). 4096 subapertures (multiple of 256). 4 quad-GPU boards (for a total of 16 GPUs). Total compute latency: 301+ us. Centroid: 5 us. (on Dell 690N) VMM: 280 us. (versus nVidia 653us) Sum: 16 us. (on Dell 690N) Servo: ?? (on Dell 690N) P3K RTC Timing

  4. Analog DSP Solution Actual timing needed on real hardware. Predictable and more familiar architecture. Assembly still needed for max performance. Optimized math library are available. Real-time host OS supported. VxWorks over VME or cPCI. Table loads not instantaneous. Typical price-performance for DSP. $21,000 per board (for a total of $168K) $12,000 for software development kit No news of speed-up in the near future. NVIDIA GPU Solution Multi-board configuration needed testing. No direct control of on-board resources. Max performance possible all in C language. Parallel programming is non-trivial. No real-time host OS supported. Is NVIDIA library callable inside Linux kernel? Instantaneous switch between tables. Unrivaled price-performance $12,000 per board (for a total of $48K) $ 0 for software development kit 2 to 3 times speed-up slated for Dec. 2007. P3K RTC Issues & Highlights

  5. P3K RTC Mgt. • Plan • Determine which solutions can do the VMM • Then from solution space decide which is best to implement • Budget/Schedule • All equipment must be received by 2/14/2008 • Should place order by ~11/1/07, lead time is ~8wks for TigerSharc boards which we assume is the longest lead time • DURIP award is $240K

  6. Discusions