RAM Timing & Latency Calculator

Nanosecond Precision Analysis & Samsung B-Die Sub-Timing Rules

Why Memory Latency Controls 1% Lows

When a game engine encounters a CPU draw call (like an opponent peeking a corner or an explosive grenade detonating), the CPU core must query system RAM. If your memory latency is 65ns instead of 36ns, the core stalls for nearly double the clock cycles, causing an instantaneous frame-time spike (a micro-stutter).

Select Hardware Profile / Benchmark Preset:

Timing Input MatrixDDR Frequency & Primaries

Memory Frequency: 4000 MT/s (MHz)

2133 MHz3600 (DDR4)6000 (DDR5)8400 MHz

CAS Latency (tCL): 16

CL12 (Extreme B-Die)CL16CL30CL44

RAS to CAS Delay (tRCD): 16

Row Precharge (tRP): 16

Row Active Time (tRAS): 32

Refresh Recovery Time (tRFC): 280 cyclesReal recovery: 140.0 ns (B-Die targets <140ns)

Latency TelemetryREAL-TIME

First Word Access Time:8.00 nsFormula: (CL × 2000) ÷ MHz

Estimated AIDA64 System Latency:33.8 nsIncludes Ring Bus & Sub-timing overhead

Theoretical Dual-Channel Bandwidth:64.0 GB/s

Performance Index:

Elite Tier (Zero Micro-Stutter)

Samsung B-Die & DDR4/DDR5 Sub-Timing Cheat Sheet

Primary timings (CL, tRCD, tRP) represent only ~35% of total memory performance. The remaining 65% of 1% low framerate stabilization comes from secondary and tertiary timings.

Timing Parameter	Role & Function	Samsung B-Die (Safe)	Tuned (Max FPS)	Golden Rule / Formula
tRFC	Row Refresh Cycle Time	300 – 350	240 – 280	Target ~130ns–140ns. Massive 1% low impact.
tFAW	Four Activate Window	24	16	Must equal 4 × tRRD_S (4 × 4 = 16).
tRRD_S / tRRD_L	Row-to-Row Delay (Short/Long)	4 / 6	4 / 4	4 / 4 on Z390 / Z690 provides optimal queue delivery.
tREFI	Refresh Interval	32767	65535 (Max)	Higher = better. Keeps memory open longer without pause.
tWR	Write Recovery Time	16	10 – 12	Directly impacts write bandwidth in open world games.
tCWL	CAS Write Latency	Equal to tCL	tCL or tCL - 2	Allows instant turnaround from read to write operations.

Stability Testing Protocol: Run TestMem5 (TM5) with Anta777 Extreme1 or Universal2 configuration for at least 3 cycles (approx 90 minutes). Zero errors are required before playing competitive ranked matches.

Memory Latency Lab

RAM & Memory Tuning FAQs

Deep dive into Samsung B-Die sub-timings, tRFC, tFAW, Gear modes, and memory stability diagnostics.

Ctrl+F

DRAM stores bit charges in microscopic capacitors that leak voltage rapidly. Every few microseconds, the memory controller must refresh all memory rows.

While a row is refreshing (the duration of tRFC), the CPU cannot read or write data to that DRAM bank. Default XMP profiles set tRFC loosely (often 600–800 cycles, or ~350ns).

Samsung B-Die memory can run tRFC down to 260–300 cycles (~130ns–150ns). This cuts bank refresh stall duration in half, eliminating memory-induced frametime hitching in esports.

Key Takeaway:

Tuning tRFC yields the single largest reduction in memory latency and the biggest increase in 1% low framerate.

Open RAM Timing & Latency Calculator

Need more details on this optimization layer?Master Zero-Latency Checklist