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DDR5-6000 CL30 first-word latency is 10.0 ns

DDR5-6000 CL30 is AMD's officially recommended sweet spot for AM5 Ryzen 7000 and 9000 processors, thanks to the 1:1 Infinity Fabric ratio that keeps memory controller latency at its minimum. Its 10.00 ns first-word latency is a genuine milestone — the first DDR5 spec to clearly beat a tuned DDR4-3600 CL16 kit (8.89 ns after correcting for tRCD differences) on every non-synthetic benchmark.

First-word latency
10.00 ns
CL30 @ 3000 MHz bus
Row cycle time (tRC)
38.7 ns
tRP + tRAS
Peak bandwidth
48.0 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)

10.00 ns

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

I/O bus clock

3000 MHz

Cycle time

0.333 ns

tRCD delay

12.67 ns

tRP delay

12.67 ns

tRAS

26.00 ns

tRC (tRP + tRAS)

38.67 ns

Peak bandwidth per channel48.0 GB/s

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

How this is calculated

At 3000 MHz bus clock, each cycle is 0.333 ns; 30 cycles of CAS latency lands on exactly 10 ns. Row cycle time is 51.3 ns, and peak per-channel bandwidth is 48 GB/s. Ryzen's Infinity Fabric runs at 2000 MHz at this memory speed — the 1:1 ratio is why most AM5 overclocking guides start from DDR5-6000 CL30 as the baseline before tuning sub-timings.

Verdict

DDR5-6000 CL30 is the single best DDR5 value target for AM5. Matched Infinity Fabric, sub-10 ns latency, and widely available XMP kits — there's essentially no reason to pick anything else unless you're chasing benchmarks on an Intel platform.

More DDR5 scenarios

DDR5-4800 CL40
CL40 • 4800 MT/s
View details ➜
DDR5-5600 CL36
CL36 • 5600 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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