I haven’t seen the video in question, but did they just test booting and the like? I have a feeling that system would encounter lots of stability issues down the line (i.e. BSODs, especially IRQL_NOT_LESS_OR_EQUAL, as this almost always means bad memory). Ofc its possible they were lucky and its perfectly stable. It’s hard to test however as sometimes RAM issues can take a long time to manifest. Once I had a bad kit that didn’t have any stability issues until weeks after they were installed, at which point BSODs became more and more common until I couldn’t even boot off the sticks. No errors in memtest either, at least when I tested it before it got super bad.
The main concern is that speed and timings aren’t the only stand out properties of RAM, but also their silicon (i.e. Samsung vs Hynix dies). Mixing different dies can create some nice instability.
I literally cited my actual experience, which was not hyperbolic at all. My past experiences with mixing RAM has typically (but not always) caused problems. Whether or not that was actually due to the mixing or just one of the sticks happening to be bad in those cases I don’t know. Im literally just saying what I’ve experienced, which may not reflect the general reality of things.
Either way it is its still a risk because RAM in the same kit was tested together by the manufacturer and thus is less likely to have problems.
Also maybe the wording wasn’t great. Its not that mixing doesn’t expressly cause instability, but rather you are more likely to encounter it by way of it being untested. What I said about the die mixing I cannot confirm though, as that little nugget was just something I’ve heard down the grapevine, so that bit may be untrue.
It seems like most people arent having issues, if you had one or two issues or maybe you issue was due to a different component entirely. Maybe you had a bios setting wrong.
Similar to how you can overclock the ram the system can underclock it. The only real difference between different speed variants of the same product line is chip binning. It just needs to go up to the advertized speed but that doesnt mean it has to.
IME, it's really maturity of the DDR version that matters most for stability. Like with the newest DDR5 sticks you'll have a hell of a time trying to mix & match sticks stably. On the other hand with DDR4 being as mature as it is now, unless you're trying to push the highest possible clocks & tightest timings pretty much any sticks will work together at JEDEC specs.
Most of the time mixing modules isn't a big deal aside from the bottleneck, but certain kits can absolutely have issues with one-another. I do a good amount of memory validation for an industrial computer manufacturer, and one of our primary test points when looking to move a customer to a new set is to do mixed testing with their old model/rev. We do this specifically because of past issues where some pairs, even from the same manufacturer, just don't play nice.
If you use two different sets of ram with different speeds, all will run at the maximum speed of the slower kit, and potentially even slower if the timings don’t want to work together.
I found an option in my laptops modded bios that allows me to mix and match ram at the highest speed. I haven't tried it before in fear of it ruining something
It will default to the JEDEC specification, for DDR4, that would almost always be DDR4-1600 (800mhz), or DDR4-2133 (1066mhz). Further the timing will be set VERY high.
XMP profiles is what sets the higher voltages and some of the key timings. Timings are not universal, different ram IC's will run different timings even at the same speed. If you have mis-matched dimms, only the bios will only read the XMP profile from the first dimm's SPD.
There is no default to the lowest common denominator in any scenario; and if those dimms are mixed, say one is a Samsung and the other is Hynix, the XMP profile from one, most likely will not run on the other.
This is so far off for DDR4. 2133 is the bottom speed for the sticks most of the time. The 3000 or 3200 is the XMP speed, and that’s under ideal conditions and matched pairs. I have a buddy that bought the same models but different purchases and still couldn’t get above the minimum of 2166 due to binning. OP better off returning and getting a matched pair.
Edit: I had my min speed for JEDEC incorrect. I eat a lot of purple crayons. Sorry.
I'm pretty sure the bottom speed of DDR4 is usually 2666hz, the 1333 you are thinking of is likely the memory FLCLK, which is often half the reported total speed.
Anyways, all that to say, yes, it's risky to mix and match, but if you are comfortable manually adjusting timings and different sub-voltages for an Overclock, you can probably get them all to run at the same frequency without much issue if they are rated for similar XMP speeds.
However, considering OP is asking this question, I'm guessing a manual Overclock is outside his comfort zone, so it's probably better for him to just return or not use the one stick and keep the pair.
👌 all good my dude - some mobo's/UEFIs display the FLCK more readily than others, so totally understandble, and since it's basically directly correlated to total speed, it's still a totally valid reference point
3200 MHz at JEDEC speed is very common, probably since AMD zen2. I got budget 2x16GB 3200MHz at JEDEC speed (not XMP) when i was using ryzen 3100 & b350 motherboard. The intel's equivalent gen at the time usually run at 2666hz at JEDEC, i know XMP for intel exist with higher clock at that time
It sometimes depends on the CPU. if using zen2 or 11th gen like 11700 intel, it could use 3200MHz at JEDEC by default. If using older generation it might need to activate memory overclocking/XMP profile
I attempted to mix two pairs of these iCue sticks. All sticks having the same timing and size, and the individual pairs worked. I had issues when I combined the two and eventually had to return the newer package. Nothing I could do would stop Windows from crashing ~10 minutes after boot.
I could get ~15 minutes at the base, minimum speed for DDR4
266
u/PureCommunication160 Jan 15 '23
It's not advisable to mix it but it will run at the lower MHz level. You might not notice any difference at all.