Is DDR5-6400 CL32 good for Intel? Latency, bandwidth, and gear-2 guide

DDR5-6400 CL32 is the Intel platform equivalent of AMD's DDR5-6000 CL30 sweet spot. It has the same 10 ns first-word latency, a bit more raw bandwidth, and is 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
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clk
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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

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. Choose this one if you're on Raptor Lake or Arrow Lake, or DDR5-6000 if you're on Ryzen 7000 or 9000.

More DDR5 scenarios

Frequently asked questions

Is DDR5-6400 CL32 stable on AMD AM5 systems?
It can be unstable on some Ryzen 7000 or 9000 systems because Zen 4/5 memory controllers often struggle to run at 6400 MT/s in a 1:1 mode. It is generally recommended for Intel platforms.
What is the true latency of DDR5-6400 CL32?
It has a first-word latency of exactly 10.00 ns, matching the latency of DDR5-6000 CL30 but with higher raw bandwidth.