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DDR5-5600 CL36 first-word latency is 12.9 ns

DDR5-5600 CL36 is the current Intel 14th-gen JEDEC spec, and the default rating for most OEM laptop and prebuilt DDR5 memory in 2026. Its 12.86 ns first-word latency is comfortably better than DDR5-4800 and matches a well-tuned DDR4-3600 kit — finally meaningful ground reclaimed by DDR5 on the timing front.

First-word latency
12.86 ns
CL36 @ 2800 MHz bus
Row cycle time (tRC)
40.0 ns
tRP + tRAS
Peak bandwidth
44.8 GB/s
Per channel

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RAM Latency Calculator

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

True Latency

First-word latency (CL)

12.86 ns

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

I/O bus clock

2800 MHz

Cycle time

0.357 ns

tRCD delay

12.86 ns

tRP delay

12.86 ns

tRAS

27.14 ns

tRC (tRP + tRAS)

40.00 ns

Peak bandwidth per channel44.8 GB/s

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

How this is calculated

2800 MHz bus clock puts a single cycle at 0.357 ns, so 36 cycles of CL is 12.86 ns. Peak per-channel bandwidth is 44.8 GB/s, about 40% more than DDR4-3200 and 17% over DDR5-4800. This is the speed grade where DDR5's latency disadvantage vs. mature DDR4 finally evaporates for most workloads — gaming benchmarks start tying or slightly winning against DDR4-3600 CL16 here.

Verdict

DDR5-5600 CL36 is the pragmatic default for any non-enthusiast build. Not the fastest, not the cheapest, but the spec where DDR5 is flat-out better than any DDR4 kit you can buy for the same money.

More DDR5 scenarios

DDR5-4800 CL40
CL40 • 4800 MT/s
View details ➜
DDR5-6000 CL30
CL30 • 6000 MT/s
View details ➜
DDR5-6400 CL32
CL32 • 6400 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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