CPU Clock Cycle / IPC Performance Calculator

Inspectable records

Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Area

Computing & Information

Tranche

tranche-4

Evidence ID

t4-299

Ledger rows

1

No ledger note is attached.

Review findings

Core formulas are standard, but the specification needs an explicit CPI-versus-IPC input contract, explicit Hz/MHz/GHz unit handling, and an explicit MIPS conversion before it can be verified as unambiguous.

Formula and scope findings

• time=instructions×CPI/clock_rate is the standard execution-time formula when clock_rate is in cycles per second and CPI is cycles per instruction.
• IPS=clock_rate/CPI is the standard throughput formula for average CPI.
• The input specification permits IPC, but no conversion rule is stated. If IPC is supplied, the standard reciprocal relation CPI=1/IPC must be applied under steady-state assumptions; IPC must not be substituted directly into the CPI formulas.
• MIPS is listed as an output, but no explicit conversion formula is given. It should be MIPS=IPS/1000000 when IPS is in decimal instructions per second.

Unit assumptions

• clock_rate is measured in hertz, meaning cycles per second; GHz and MHz must be converted to Hz before calculation.
• instruction_count is a nonnegative count of instructions.
• CPI is measured in cycles per instruction and must be positive.
• IPC is measured in instructions per cycle and, when accepted, is converted using CPI=1/IPC with IPC>0.
• execution time is reported in seconds.
• IPS is reported in decimal instructions per second; MIPS means decimal millions of instructions per second, using 1 MIPS=1000000 instructions per second.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

CPI=0 produces an undefined IPS result and should be rejected; the input-schema CPI-versus-IPC switch and clock-rate unit convention can also produce drastically different outputs if interpreted incorrectly.

Errata and corrections

No applied erratum is attached to this unique-name record.

Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

{
  "inputs": {
    "clock_rate_hz": 2500000000,
    "instruction_count": 4000000000,
    "CPI": 1.25
  },
  "expected_outputs": {
    "execution_time_seconds": 2,
    "IPS": 2000000000,
    "MIPS": 2000
  },
  "working": "cycles = 4000000000 instructions × 1.25 cycles/instruction = 5000000000 cycles; execution time = 5000000000 cycles ÷ 2500000000 cycles/second = 2 seconds; IPS = 2500000000 cycles/second ÷ 1.25 cycles/instruction = 2000000000 instructions/second; MIPS = 2000000000 ÷ 1000000 = 2000 MIPS."
}

Related workflows

No source-defined multi-instrument workflow membership is recorded.

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json · VERIFIED_CLEAN
• evidence-tranche4/tranche4-results.json
• BOUNDARY_HAZARD_CATALOG.json