Andrew Fribush
fig. 2.2.8 · the selector's cost model against measured time.
PREPARED-QUERY TIME ÷ MEASURED TIME OF THE PICKED ROUTE · RTX 4090 · 36 CELLSMedian miss 3.04%. The worst six, −33.5 to −36.1%, are the dense-output control, where both routes ran slow alike.One row is one test cell: ring = the selector’s prediction, dot = the measurement; accent = the route it picked, grey = the route it passed over.EXISTING WORKLOADSdense output 0.8: picked dense, predicted 1.19 ms, measured 1.82 ms (−34.9%). Passed over screening (rank128): predicted 1.25 ms, measured 1.93 ms.dense output0.8dense−34.9%predicted 1.19 msmeasured 1.82 msdense output 0.9: picked dense, predicted 1.19 ms, measured 1.81 ms (−34.4%). Passed over screening (rank128): predicted 1.25 ms, measured 1.98 ms.0.9dense−34.4%dense output 0.95: picked dense, predicted 1.19 ms, measured 1.80 ms (−33.7%). Passed over screening (rank128): predicted 1.25 ms, measured 2.11 ms.0.95dense−33.7%clustered 0.8: picked dense, predicted 55.85 ms, measured 57.76 ms (−3.3%). Passed over screening (rank64): predicted 70.99 ms, measured 71.16 ms.clustered0.8dense−3.3%clustered 0.9: picked dense, predicted 55.95 ms, measured 58.56 ms (−4.5%). Passed over screening (rank64): predicted 70.94 ms, measured 71.32 ms.0.9dense−4.5%clustered 0.95: picked rank128, predicted 25.99 ms, measured 20.26 ms (+28.3%). Passed over dense: predicted 55.77 ms, measured 57.45 ms.0.95rank128+28.3%isotropic 0.8: picked dense, predicted 55.76 ms, measured 57.49 ms (−3.0%). Passed over screening (rank64): predicted 70.73 ms, measured 70.84 ms.isotropic0.8dense−3.0%isotropic 0.9: picked rank128, predicted 26.53 ms, measured 25.47 ms (+4.2%). Passed over dense: predicted 56.06 ms, measured 57.42 ms.0.9rank128+4.2%isotropic 0.95: picked rank128, predicted 18.42 ms, measured 18.10 ms (+1.8%). Passed over dense: predicted 55.80 ms, measured 57.42 ms.0.95rank128+1.8%COCO 0.8: picked dense, predicted 165.04 ms, measured 177.38 ms (−7.0%). Passed over screening (rank64): predicted 179.69 ms, measured 188.69 ms.COCO0.8dense−7.0%COCO 0.9: picked rank64, predicted 45.03 ms, measured 45.54 ms (−1.1%). Passed over dense: predicted 65.53 ms, measured 65.95 ms.0.9rank64−1.1%COCO 0.95: picked rank64, predicted 27.91 ms, measured 27.12 ms (+2.9%). Passed over dense: predicted 51.25 ms, measured 51.22 ms.0.95rank64+2.9%arXiv 0.8: picked rank128, predicted 46.52 ms, measured 45.14 ms (+3.1%). Passed over dense: predicted 73.50 ms, measured 72.95 ms.arXiv0.8rank128+3.1%arXiv 0.9: picked rank64, predicted 26.25 ms, measured 25.81 ms (+1.7%). Passed over dense: predicted 63.68 ms, measured 64.04 ms.0.9rank64+1.7%arXiv 0.95: picked rank64, predicted 24.87 ms, measured 23.77 ms (+4.6%). Passed over dense: predicted 62.92 ms, measured 62.42 ms.0.95rank64+4.6%GloVe 0.8: picked dense, predicted 30.74 ms, measured 31.90 ms (−3.6%). Passed over screening (rank25): predicted 31.86 ms, measured 32.46 ms.GloVe0.8dense−3.6%GloVe 0.9: picked dense, predicted 25.56 ms, measured 24.93 ms (+2.5%). Passed over screening (rank25): predicted 26.03 ms, measured 25.44 ms.0.9dense+2.5%GloVe 0.95: picked dense, predicted 23.37 ms, measured 23.56 ms (−0.8%). Passed over screening (rank25): predicted 23.96 ms, measured 23.98 ms.0.95dense−0.8%↑ both routes ran ~35% slower thanpredicted; the order held0.6×0.8×1×1.5×2×3×← flip zone: 0 grey dotspassed-over route slower →PREDECLARED HOLDOUTdense output 0.85: picked dense, predicted 1.19 ms, measured 1.79 ms (−33.5%). Passed over screening (rank128): predicted 1.27 ms, measured 2.02 ms.dense output0.85dense−33.5%dense output 0.925: picked dense, predicted 1.19 ms, measured 1.87 ms (−36.1%). Passed over screening (rank128): predicted 1.26 ms, measured 2.05 ms.0.925dense−36.1%dense output 0.975: picked dense, predicted 1.19 ms, measured 1.81 ms (−34.0%). Passed over screening (rank64): predicted 1.26 ms, measured 2.07 ms.0.975dense−34.0%clustered 0.85: picked dense, predicted 55.94 ms, measured 57.33 ms (−2.4%). Passed over screening (rank64): predicted 70.91 ms, measured 70.91 ms.clustered0.85dense−2.4%clustered 0.925: picked rank128, predicted 27.33 ms, measured 26.43 ms (+3.4%). Passed over dense: predicted 55.82 ms, measured 57.05 ms.0.925rank128+3.4%clustered 0.975: picked rank128, predicted 18.58 ms, measured 18.14 ms (+2.4%). Passed over dense: predicted 55.80 ms, measured 57.03 ms.0.975rank128+2.4%isotropic 0.85: picked dense, predicted 55.87 ms, measured 57.61 ms (−3.0%). Passed over screening (rank64): predicted 70.94 ms, measured 71.27 ms.isotropic0.85dense−3.0%isotropic 0.925: picked rank128, predicted 24.09 ms, measured 19.67 ms (+22.5%). Passed over dense: predicted 55.93 ms, measured 57.80 ms.0.925rank128+22.5%isotropic 0.975: picked rank128, predicted 18.54 ms, measured 18.09 ms (+2.5%). Passed over dense: predicted 55.78 ms, measured 57.37 ms.0.975rank128+2.5%COCO 0.85: picked rank128, predicted 80.39 ms, measured 85.56 ms (−6.0%). Passed over dense: predicted 97.85 ms, measured 102.58 ms.COCO0.85rank128−6.0%COCO 0.925: picked rank64, predicted 33.69 ms, measured 32.76 ms (+2.9%). Passed over dense: predicted 55.77 ms, measured 55.78 ms.0.925rank64+2.9%COCO 0.975: picked rank64, predicted 25.00 ms, measured 24.45 ms (+2.3%). Passed over dense: predicted 48.80 ms, measured 48.83 ms.0.975rank64+2.3%arXiv 0.85: picked rank128, predicted 29.12 ms, measured 29.65 ms (−1.8%). Passed over dense: predicted 64.26 ms, measured 65.51 ms.arXiv0.85rank128−1.8%arXiv 0.925: picked rank64, predicted 25.42 ms, measured 24.77 ms (+2.6%). Passed over dense: predicted 63.59 ms, measured 63.89 ms.0.925rank64+2.6%arXiv 0.975: picked rank64, predicted 24.63 ms, measured 23.39 ms (+5.3%). Passed over dense: predicted 61.22 ms, measured 60.67 ms.0.975rank64+5.3%GloVe 0.85: picked dense, predicted 26.46 ms, measured 26.78 ms (−1.2%). Passed over screening (rank25): predicted 27.46 ms, measured 27.88 ms.GloVe0.85dense−1.2%GloVe 0.925: picked dense, predicted 23.63 ms, measured 23.91 ms (−1.2%). Passed over screening (rank25): predicted 24.22 ms, measured 24.44 ms.0.925dense−1.2%GloVe 0.975: picked dense, predicted 23.37 ms, measured 22.89 ms (+2.1%). Passed over screening (rank25): predicted 23.99 ms, measured 23.41 ms.0.975dense+2.1%↑ the same in the holdout0.6×0.8×1×1.5×2×3×← flip zone: 0 grey dotspassed-over route slower →

source: gpu-threshold-join portfolio-selector-2026-09-18 validation/prediction-audit.json · selector/selector.csv:3-73 · SELECTOR-NVIDIA-2026-09-18.md:156-162 · costModel.data.ts

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Andrew Fribush, software and computer engineer in Austin. I build consequential systems where software meets institutions: finance, healthcare, commerce, government data, and the mechanisms that govern AI agents. Taking new engagements: hello@andrewfribush.com.