2 Timing Sample

A fixed sample of images was randomly and proportionally selected from the ELFT datasets. The sample is used to assess whether an implementation adheres to the computational speed requirements from the ELFT Test Plan. These values are chosen in such a way that allows the implementation flexibility while allowing NIST to complete the evaluation in a reasonable amount of time. If an implementation exceeds the maximum allowable duration, the participant will be asked to reduce the processing time of their software prior to NIST completing the evaluation. As such, all published ELFT submissions conform to the published speed requirements.

2.1 Processor Details

All measurements in this section were performed on a machine equipped with Intel Xeon Gold 6254 Central Processing Units (CPUs). Each CPU features a 3.10 GHz base frequency and 24.75 MB of cache. Timing tests are all single threaded—implementations are not permitted to use more than one thread during any function measured here. As such, these values can be used to understand expected scaled performance. NIST testing code embraces the single-threaded nature of implementations to fork processes during other non-timed portions of this evaluation, allowing participants to write thread-unsafe code while still using NIST resources to their maximum efficiency. This CPU supports executing several families of processor intrinsic functions, including AVX-5121.

2.2 Composition

Table 2.1 shows the quantity of each type of fingerprint image comprising the timing sample dataset.

Table 2.1: Number of images of each generalized finger position comprising the timing sample dataset.
Image Type Quantity
Latent 243
Four Finger 476
Full Palm 40
Partial Palm 47
Single Finger 2 784

2.3 Feature Extraction

Features were extracted from all images depicted in Table 2.1 and stored in templates. If a sample contained EFS data, it was included during this test.

2.3.1 Template Size

Table 2.2 and Figure 2.1 show the distribution of file sizes of templates. Failures of any kind reported during template generation result in NIST code writing 0 byte files. These files are excluded from the template size analysis in this section.

Table 2.2: Template file size summary statistics as seen on the Timing Sample dataset, in kB.
Image Type Minimum 25% Median Mean 75% Maximum Failures Attempts
Latent 80.3 110.3 122.1 127.0 139.4 219.3 0 243
Single Finger 2.0 3.7 4.2 4.3 4.9 7.7 0 2 784
Four Finger 7.5 12.1 13.2 13.4 14.5 18.4 0 476
Partial Palm 0.3 11.3 13.3 11.7 14.7 17.4 0 47
Full Palm 15.7 19.0 20.5 20.2 21.7 23.2 0 40
Violin plot of template file sizes as seen on the  Timing Sample dataset. Vertical lines from left to right indicate the 25\%, 50\%, and 75\% quantiles respectively.

Figure 2.1: Violin plot of template file sizes as seen on the Timing Sample dataset. Vertical lines from left to right indicate the 25%, 50%, and 75% quantiles respectively.

2.3.2 Template Creation Duration

Table 2.3 and Figure 2.2 show the distribution of template creation durations in seconds. Failures of any kind reported during template generation result in NIST code writing 0 byte files, but only after the template creation method returns. These times are included in the template creation duration analysis in this section.

Table 2.3: Duration of template creation in seconds for images from the Timing Sample dataset.
Image Type Minimum 25% Median Mean 75% Maximum Failures Attempts
Latent 4.8 7.5 8.7 9.7 10.9 37.7 0 243
Single Finger 0.5 1.2 1.4 1.4 1.7 2.7 0 2 784
Four Finger 2.5 4.2 4.6 4.7 5.2 7.1 0 476
Partial Palm 1.3 4.8 5.8 5.3 6.4 7.5 0 47
Full Palm 8.3 10.1 10.6 10.7 11.1 13.1 0 40
Violin plot of the duration of template creation in seconds for images from the Timing Sample dataset. Vertical lines from left to right indicate the 25\%, 50\%, and 75\% quantiles respectively.

Figure 2.2: Violin plot of the duration of template creation in seconds for images from the Timing Sample dataset. Vertical lines from left to right indicate the 25%, 50%, and 75% quantiles respectively.

2.3.3 Template Creation Memory Consumption

Figure 2.3 shows the amount of RAM consumed by the single testing process as a function of time during the template creation procedure, including RAM consumed by the NIST testing apparatus.

Amount of RAM used while creating templates in the Timing Sample dataset.

Figure 2.3: Amount of RAM used while creating templates in the Timing Sample dataset.

2.4 Enrollment Database

Reference templates are combined into a participant-defined database structure for optimal searching. Each database consisted of  ≈ 1 600 000 distractor subjects. Each subject had at least one, but typically twenty, distal phalanges distributed over rolled and flat impression captures to enroll.  ≈ 150 000 had one or more palm captures.

While the participant-defined enrollment database should contain information about all references, the file size may be significantly different than the space consumed by concatenation of all individual reference templates. Additionally, the participant-defined database structure may be a structure unique or especially optimized for this evaluation and not necessarily similar to a structure deployed operationally. The sum of file sizes for both types of reference storage are shown in Table 2.4.

Table 2.4: Sum of file storage needed to hold all distractor reference templates in the Timing Sample.
Storage Type Size
Participant-Defined Enrollment Database 305.1 GB
Raw Templates on Disk 127.5 GB

  1. The complete set of advertised CPU flags is fpu, vme, de, pse, tsc, msr, pae, mce, cx8, apic, sep, mtrr, pge, mca, cmov, pat, pse36, clflush, dts, acpi, mmx, fxsr, sse, sse2, ss, ht, tm, pbe, syscall, nx, pdpe1gb, rdtscp, lm, constant_tsc, art, arch_perfmon, pebs, bts, rep_good, nopl, xtopology, nonstop_tsc, cpuid, aperfmperf, pni, pclmulqdq, dtes64, monitor, ds_cpl, vmx, smx, est, tm2, ssse3, sdbg, fma, cx16, xtpr, pdcm, pcid, dca, sse4_1, sse4_2, x2apic, movbe, popcnt, tsc_deadline_timer, aes, xsave, avx, f16c, rdrand, lahf_lm, abm, 3dnowprefetch, cpuid_fault, epb, cat_l3, cdp_l3, invpcid_single, intel_ppin, ssbd, mba, ibrs, ibpb, stibp, ibrs_enhanced, tpr_shadow, vnmi, flexpriority, ept, vpid, ept_ad, fsgsbase, tsc_adjust, bmi1, avx2, smep, bmi2, erms, invpcid, cqm, mpx, rdt_a, avx512f, avx512dq, rdseed, adx, smap, clflushopt, clwb, intel_pt, avx512cd, avx512bw, avx512vl, xsaveopt, xsavec, xgetbv1, xsaves, cqm_llc, cqm_occup_llc, cqm_mbm_total, cqm_mbm_local, dtherm, ida, arat, pln, pts, pku, ospke, avx512_vnni, md_clear, flush_l1d, arch_capabilities