Micron’s next DDR5 evolution – Crucial DDR5 Pro and Pro overclocking kits review with Teardown and OC

Crucial Pro 2x 16 GB DDR5-5600 at DDR5-7000 38-45-44-96 1.2 V

Contrary to its name, the “not OC” kit can be easily overclocked to DDR5-7000, which is completely stable and suitable for everyday use. It is important that the voltage is not increased too much, as this will result in “rollover”, i.e. the stability will deteriorate again with a higher voltage. 1.2 V is already the sweet spot for this kit – with more voltage the clock rate is no longer stable, with less voltage the timings should be a little looser. The fact that the PMIC does not allow more than 1.435 V is therefore completely irrelevant for these ICs.

These modules with Micron 16 Gbit Rev D memory chips are therefore roughly comparable to Samsung 16 Gbit B-Die or SK Hynix 16 Gbit M-Die in terms of clock rate and performance. Micron can now deliver what these manufacturers were able to offer at the time of the market launch of DDR5 and Alder Lake, at least in the 16 Gbit variant. The slightly larger 24 Gbit RevB ICs from Micron with comparable performance have been around for a while – click here for our test.

While “only” 7000 Mbps is stable on the Asus Maximus Z790 Hero 4-DIMM mainboard, the Z790 Apex 2-DIMMer with these ICs can achieve a little more. Up to DDR5-7466 then run stably there, but also with only 1.2 V – true to the motto: less voltage is more stability. But since our primary RAM test board is the Z790 Hero, let’s get back to its OC settings and timings. Voltages for SA, VDD2 (MC) and CPU VDDQ (VDDQ TX Transmitter) do not need to be adjusted at all and run smoothly with the auto settings, although these behave differently on almost every motherboard anyway.

Primary timings tCL 38, tRCD 45, tRP 44 and tRAS 88 are respectable values for 7000 Mbps. tRCDWR can be set to the minimum of 8 for a free performance boost, as with most DDR5 ICs. For the secondaries, tRRD_sg, tRRD_dg and tFAW with 8/8/32 are also respectable, for DDR5 ICs it really doesn’t get any better than this. The refresh timings of tRFC 558 and tRFC_SB 454 are also not bad at all, together with tREFI 131072. However, the timing cannot be fully exploited due to the temperature, as otherwise the system tends to crash at the end of the stress test. Of course, this setting is also very dependent on the temperature of the modules. Here I have a 120 mm fan with 600 rpm on the modules to simulate the light air flow in a case.

Like all non-Hynix DDR5 ICs, Micron 16 Gbit RevD is much more difficult to write than to read. tCWL can be minimized to 30, but you still have to be patient with the tertiaries for write operations. tWRWR_sg/dg 28/8 as well as tWRRD_sg/dg 68/50 and tWRPRE 74 are really not fast and cost performance. At least the read operations are relatively fast with tRDRD_sg/dg 12/8 and tRDWR_sg/dg 17/17 – that’s pretty good for DDR5!

Crucial Pro Overclocking 2x 16 GB DDR5-6000 at DDR5-7000 38-39-40-94 1.2 V

Contrary to its name, the “OC” kit can’t really be overclocked any further than the normal one – even DDR5-7000 is the limit for reproducibly stable operation. The primary timings can be tightened a little more with tRCD 39, tRP 40 and tRAS 94, but tWRPRE/tWRPDEN(tWR) must be loosened a little to 102. In terms of performance, this is a measurable but small advantage over the non-“OC” Crucial DDR5 Pro kit.

The sweet spot at the voltage of 1.2 V VDD/VDDQ is also present here. Indirectly, however, this also means that this kit runs at 1.35 V in the XMP profile at DDR5-6000 with significantly more voltage than is actually necessary or even optimal for this clock rate. Of course, we cannot draw conclusions about all Micron 16 Gbit RevD production batches and their properties on the basis of 2 kits, but the 1.2 V as the optimum value for OC in our two test kits is also unlikely to be a coincidence. This also makes the non-existent OC PMIC irrelevant for more than 1.435 V VDD/VDDQ.

Micron’s new 16 Gbit DDR5 ICs are a good step towards overclocking potential, even with their effective voltage limiting. If one could now imagine that the ICs actually scale with voltage, then Micron could soon be moving in the direction of SK Hynix products and DDR5-8000, at least in terms of clock speed.

Overclocking on AMD – Crucial Pro Overclocking 2x 16 GB DDR5-6000 at DDR5-6600 36-37-37-49 1.2 V

Since Crucial’s new kits with clock rates up to DDR5-6000 should also be interesting for AM5 users, I naturally didn’t want to skip overclocking on the AMD platform. Since we are stuck here at the limit of the 1:1 mode of UCLK:MCLK, unless you can run significantly higher clock rates (8000 ) on the RAM, the timings are more interesting here.

After all, 6600 Mbps at 1.2 V VDD/VDDQ and 1.3 V SOC run stably on the Asus Crosshair X670E Gene. Due to the relatively high SOC voltage, the Infinity Fabric suffers slightly at only 2133 MHz, but this is supposed to be about the RAM. Assuming the clock rate of DDR5-6600, the primary timings can be tightened to tCL 36, tRCD 37, tRP 37 and tRC 110, whereby tRAS 49 effectively becomes irrelevant. tRFC behaves analogously to the Intel platform here and has its minimum pretty much exactly at the JEDEC reference value. And here, too, you can see how the ICs find it much easier to read than the slices with tRDRDSCL 5 and tWRWRSCL 24.

We only have benchmark diagrams with reference values for the Intel platform, which is why I have included a few benchmarks here in the screenshot. Considering that the CPU clock rate of the Ryzen 9 7950X is capped at 5 GHz, a good 45 seconds in y-cruncher 2.5b and just under 13000 points in the Geekbench3 multi-core memory score are very respectable. The new Crucial Pro kits with their new Micron 16 Gbit Rev D ICs also perform more than passably on AMD.

Compatibility

I didn’t mention it specifically at the beginning, but since there is now some negative feedback about the Crucial Pro Kits in terms of compatibility, I wanted to briefly share my experiences. I had no problems at all with the Asus Maximus Z790 Hero and the Asus Crosshair X670E Gene. Whether with a BIOS from the end of last year or a brand new release, the kits always started up without any problems with the JEDEC settings and loading the XMP or EXPO profiles also went off without any complications. Even during a quick counter-test on the ASRock X670E PG Lightning, the Crucial Pro modules had no boot problems whatsoever.

Of course, this is only my personal experience and other motherboard manufacturers such as Gigabyte, MSI or Biostar could have bigger problems, but since the clock rates of the Crucial Pro kits are rather low anyway, the potential problems should be solved relatively soon, if they are not already. And with AM5, AMD and its AGESA have complete control over RAM OC anyway, so everything should be fine with an up-to-date BIOS, regardless of the motherboard manufacturer.