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DDR5-6400 CL32 first-word latency is 10.0 ns

DDR5-6400 CL32 is the Intel platform equivalent of AMD's DDR5-6000 CL30 sweet spot — same 10 ns first-word latency, a bit more raw bandwidth, and widely supported by Z790 and Z890 boards. It's the XMP rating most "high-performance" DDR5 kits bin for in 2026.

First-word latency
10.00 ns
CL32 @ 3200 MHz bus
Row cycle time (tRC)
37.2 ns
tRP + tRAS
Peak bandwidth
51.2 GB/s
Per channel

Calculator

RAM Latency Calculator

MT/s
clk
clk
clk
clk

Timings are in memory clock cycles. True latency in nanoseconds is derived from the data rate.

True Latency

First-word latency (CL)

10.00 ns

Time from a read command to the first bit of data arriving.

I/O bus clock

3200 MHz

Cycle time

0.313 ns

tRCD delay

12.19 ns

tRP delay

12.19 ns

tRAS

25.00 ns

tRC (tRP + tRAS)

37.19 ns

Peak bandwidth per channel51.2 GB/s

Assumes one 64-bit channel. Dual channel doubles this, quad channel quadruples it.

How this is calculated

3200 MHz bus clock, 0.3125 ns per cycle, 32 cycles of CL = 10.00 ns. Peak per-channel bandwidth comes in at 51.2 GB/s — 33% more than DDR5-4800 and roughly matching DDR5-8000 kits once you account for their typically looser CAS latencies. On Intel's ring bus memory controller, the 6400 MT/s speed is comfortable with gear-2 ratio and delivers a larger practical gain than the paper numbers suggest.

Verdict

DDR5-6400 CL32 is the matching Intel sweet spot to DDR5-6000 CL30 on AMD. Pick based on your CPU — this one if you're on Raptor Lake or Arrow Lake; DDR5-6000 if you're on Ryzen 7000 or 9000.

More DDR5 scenarios

DDR5-4800 CL40
CL40 • 4800 MT/s
View details ➜
DDR5-5600 CL36
CL36 • 5600 MT/s
View details ➜
DDR5-6000 CL30
CL30 • 6000 MT/s
View details ➜
DDR5-7200 CL34
CL34 • 7200 MT/s
View details ➜
DDR5-8000 CL38
CL38 • 8000 MT/s
View details ➜

Frequently asked questions

What's the true latency of DDR5-6000 CL30?
True latency = (CL × 2000) ÷ speed = (30 × 2000) ÷ 6000 = 10 ns. That's one of the fastest mainstream kits currently shipping; most DDR5-6000 kits at stock JEDEC timings sit closer to 13-14 ns.
How do CL and MHz affect RAM speed?
Data rate (MHz) determines how much bandwidth you get; CL determines how long you wait for the first bit. Higher MHz + lower CL = more throughput plus faster access. A kit with twice the MHz and equal CL halves the true latency in nanoseconds.
Is DDR5-6000 CL30 better than DDR4-3600 CL16?
DDR5-6000 CL30 is 10 ns true latency; DDR4-3600 CL16 is 8.9 ns — DDR4 is actually slightly lower latency on that comparison. But DDR5-6000 has nearly 67% more bandwidth, which matters far more for modern CPUs, especially AMD Ryzen 7000/9000 and Intel 12th-gen+.
What are tRCD, tRP, and tRAS?
Secondary timings. tRCD is the delay to activate a row before accessing a column; tRP is the time to close a row before opening another; tRAS is the minimum time a row must stay open. All three are measured in cycles; converting to ns uses the same formula as CL.
Does faster RAM help gaming?
On AMD Ryzen and modern Intel platforms, yes — especially in CPU-bound 1080p titles where the gap between DDR5-5200 CL40 and DDR5-6400 CL32 can be 10-20 fps. At higher resolutions the GPU becomes the bottleneck and RAM speed matters less.
What is JEDEC vs XMP/EXPO?
JEDEC is the default SPD profile every DIMM boots with — conservative timings guaranteed to work anywhere. XMP (Intel) and EXPO (AMD) are overclocking profiles stored on the DIMM that you enable in BIOS to unlock the speeds printed on the heatspreader.

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