The overclocking ability of these kits is easy to summarize with a “it depends” but the devil is indeed in the details. Big Boi dual-rank sticks do not overclock as well as single rank. It has nothing to do with the RAM itself and rather boils down to the inherent abilities of your particular CPU and its Integrated Memory Controller. So if you have fantasies over CL32 or DDR5-Plaid CAS timings… you should not even be thinking about buying any dual rank (“2R”) sticks. 1D1R and a golden IMC is the only way to see your dreams become reality.
This lackluster IMC options is however why we use two testbeds instead of just one. Basically by using both an AMD and then an Intel based testbed it gives us two points of view to base our final judgment on instead of just one. Thus helping to minimize any IMC quirks that do crop up from time to time.
Right now Intel’s IMC is slightly better than AMDs when it comes to higher frequencies on dual rank DIMMS. This is not to say AMD’s is a slacker of an IMC but Intel does have a slight edge. Not enough to pick one over the over other… but a slight edge. For most it will not matter as these are factory overclocked edition RAM and most of the hard work has been done for you.
Furthermore, both systems POST’ed at DDR5-6400 and were stable with both kits… and neither IMC would allow us to go higher than 6400 with dual rank DIMMS. It is what it is. With that said… at 6400 our Intel rig allowed us to tweak the 6400 kit from a flat forty (aka 40-40-40) to a flat 38 (aka 38-38-38) by just upping the voltage to 1.4v and tightening up the timings. With the “DDR5-6000” kit we were able to push it to DDR5-6400 but were unable to hit 38-38-38 at 1.4v. Instead we would have had to up the voltage further to get below 40-40-40… and to be honest 1.4v is already past our comfort zone. To us 1.35v (on a 1.1v standard) is already pushing things as far as we are concerned.
Interestingly enough on our AMD Ryzen 9 9950X system we were able to tighten up the timings a bit better than on the Intel system. Albeit at lower frequencies. So while both kits did indeed max out at DDR5-6400 by lowering our expectations back down to ‘mere’ DDR5-6200 frequencies we were able to dial both the 6400 kit and 6000 kit to 37-37-37 (both using 1.4v). Whereas on the Intel Core 285K testbed both 6200 vs 6400 made no tangible difference from a timing point of view… with these kits of RAM and this particular CPU’s IMC.
Based on these results it is obvious that Crucial has done most of the hard work for you and given you a ‘out of the box’ experience that will take time and luck to beat. As such we would not bother with either kit if manual overclocking is what you are after. Conversely, if you just want a drama free build where you will be getting a lot of performance out of big boi sticks both kits are rather good. So good that it would come down to if the difference in asking price between the two is enough to opt for 6000 over the 6400. For some builds the extra fifteen bucks is a rounding error and the DDR5-6400 kit is a ‘no-brainer’ option. One where you can get tighter timings “out of the box” than what the DDR5-6000 kit’s SPD comes programed with. For other builds… $15 savings is fifteen dollars’ worth of savings. Since DDR5-5600 is pretty much the only (thing closest to a) guarantee in life with this generation of both AMD and Intel based systems that is money that can be put elsewhere with little real-world performance loss. Possibly even no real-world performance loss, and just ‘future proofing’ / theoretical performance loss. Either way. Color us highy impressed and we will be stocking on both for future client builds!
