A Question for RAM overclocking Gurus
LeatherGryphon
Posts: 11,652
Complaint: Arghhh... I just noticed that my papa-bear machine, the big cheese, el gordo, my primary DAZing machine is not taking full advantage of its RAM. A few weeks ago I added 16GB to the existing 32GB. I used the same brand, same speed (Corsair Vengeance LPX 3200MHz) The 32GB set worked fine at 3200MHz but after I added the extra 16GB set into the two unoccupied slots, my system didn't even POST the first time, so I forced a reboot by holding the power button for 10 seconds and the machine came up OK. I never checked the RAM speed until a couple days ago and discovered that I'm running at the much slower, standard speed of 2133MHz and the XMP setting is "Disabled". Grump!
Apparently the 1st boot fails and the system automatically and turns off the XMP feature of my RAM and falls back to standard speed, so it boots the 2nd time just fine, but running slower than I want. Boogers.
I've repeated this test sequence several times and each time after setting the XMP feature, the system fails to POST but will reboot on the 2nd try after it disables the XMP feature.
Upon checking the RAMs they look identical. They all came in official looking Corsair boxes. However, the internal meta data on both sticks of my original 32GB set identifies the manufacturer as "Samsung", which is expected because Samsung is a major memory chip foundry that makes memory for other companies. However, the metadata on both of my 16GB set of RAM identifies the manufacturer as "<empty>". All other internal meta data specifications are identical including the XMP setting details. Yet, the system will not POST with XMP turned on.
Question for the overclocking Gurus: I'm suspecting that the XMP software doesn't think the 16GB modules are compatible with the 32GB modules. Is this normal? Is there any possibility of skipping the XMP settings and instead tweaking the RAM voltages & timings manually to my desired 3200MHz speed? Or am I barking up the wrong tree? Or did I get a counterfeit set of RAM?
I've never done manual RAM overclocking. Need words of encouragement & wisdom.
Motherboard is Asus Prime Z490-A, CPU is Intel i7-10700
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Comments
More data: I removed the two RAM modules that comprise the 16GB portion and left the 32GB portion in the primary slots. System works OK at 3200MHz.
I removed the two RAM sticks that comprise the 32GB portion and put the 16GB modules in their place. System boots OK at 3200.
I moved the 16GB of RAM into the secondary slots and put the 32GB of RAM modules back into the remaining two empty slots, and it fails to POST.
So, the 16GB RAM is functional at 3200MHz but not when paired with the 32GB modules.
Now assuming my choices are:
1) Buy a 4 module 64GB matched set of RAM. $$$
2) Buy two more modules and hope they behave better.
3) Remove the misbehaving 16GB and set it on the shelf until I find a use for 16GB at 3200MHz in some other machine.
4) Leave the 16GB and the 32GB sets of RAM in the machine and just be happy with 48GB of 2133MHz RAM. (c'mon, be serious
)
5) Try to manually set RAM overclocking variables to get my 16GB and 32GB of RAM playing well together at high speed.
Total newbie at this so I need advice.
Note: I also upgraded the UFEI BIOS on the motherboard from 2201 to 2301. Made no difference.
About 1-2 years ago I had an issue with my workhorse machine where the RAM started failing on me. Similar situation with Corsair Vengence chips where they started to lose functionality then failed completely. I juggled them around until I could find the offending one and pulled that one and it's mate.
A couple of weeks later and the same issue happened again. I retrieved the remaining good set from the previous pair and used it to determine which one was failing. I ordered a replacement pair and everything was fine.
For a few weeks later when another one failed. This time it was from the pair of new chips. Which was very puzzling. I juggled again and went back to the two old chips.
Before they could fail, the SSD gave up the ghost. At this point I cut my losses and tossed the motherboard and most of the other components. I figured there was something else going on and trying to diagnosis it any further was going to be more expensive than replacing it. I was able to salvage the most expensive bits (my two GPUs) and things like the power supply and fans.
For the moment I've left all the RAM in the machine. 16 + 32 = 48GB. They run just fine at 2133MHz so, I'm "happy" with that, temporarily. I need the quantity of RAM more than the speed.
Although this problem has opened an opportunity for me to justify purchase of faster morer matching set of 64GB of RAM and taking the incompatible 16GB pair to put into my baby-bear machine. Currently baby-bear's motherboard "Asus TUF GAMING B450M-Plus-II" is capable of supporting RAM at 3200MHz but is limited by the CPU "AMD Ryzen5-1400" to 2666MHz, and that's what it has.
Fortunately though, I have a new CPU "Ryzen5-5600G" in my hot little hands that is going to replace the old one very soon. Wheee... I found a home for my 16GB 3200 RAM.
So, sometime soon, when angry clouds gather in the hazy air and the snow is deep and the wind is howling like angry creatures or spoiled children, I'll have an indoor task to fill the time.
Here is a reason why I never mix and match different memory sizes. Never know what kind of problems you end up with there can be many reasons this is happing. different timings, if they are the same that's not it. I'm sure you staggered the chips right? Didn't like didn't 32s next to each other? If I remember right the Z490 wants the chips staggered. 32, 16, 32 ,16
i havwent been able to OC my 3200mhz. it alwys reads 2133 or crashes the boot if i try to go to 3200. hopefully someone explains how to do this manually. I have an ASUS Prime B450
That would be correct, when it comes to mixing ram sizes that are of the same brand and speed and so on, it does need to be as you said in a 32,16,32,16 configuration as it is to do with how it all works.. It does sound odd that with 4 ram slots the configuration is usually something like 1,3,2,4 with 1 and 2 being channel A, with 3 and 4 being channel B, again it is weird but that is how it they designed it..
I never overclock anything on a machine meant to render
... it's quite simply asking for trouble.
Setting RAM to run at a speed I don't think is really considered an overclock. I think the problem is, if I read right, most consumer grade CPU/Mobo are dual channel, not quad channel. That means it can run faster speed runnning two sticks of RAM, than it can while running four, reguardless of the speed the stick is supposed to be able to handle. At least that is what I got out of reading when I was upgrading. You can go faster using 2 16gb sticks, than you can usin 4 8gb sticks for example.
that could be part of it. I was able to ge tmine to 3200 with 2 8gb sticks. When I went to 4 8gb it wouldnt work. They are all the same overall, bought matched sets and did put them in that 1-3, 2-4 config.
This is unfortunally relatively normal behaviour. Many desktop processors and motherboards have dual channel memory, but often have 4 dimms.
So you don't notice anything off or wrong, when you use 2 dimms, until you add 2 more to use it fully and system adjusts to what it can cope with (bandwidth limit).
So either accept this situation, you got more RAM, or go back to what you had before with 2 dimms, or buy some new 2 dimms, that are twice what you had before, so have more RAM, either way you stick to 2 dimms.
Manuals sometimes give more insight in this area, but this time (I checked), they didn't, it however is a common thing, it's best to stick to 2 dimms on dual channel architecture, unless you accept RAM speed being of least concern.
I think the performance boost you get by having more RAM is way better than running less RAM at a bit higher speed, but I am no expert and only did some cursory benchmark tests to come up with that lol
Here's the link to your motherboard manufacturer website.
https://www.asus.com/us/Motherboards-Components/Motherboards/PRIME/PRIME-Z490-A/HelpDesk_QVL_Memory/
This tool will show you what RAM it can use and in what configuration.
Select the vendor and speed then match up the part numbers to see if the RAM you own is "supported".
You might get it to run if you manually set the correct DRAM voltage and speed.
https://www.asus.com/support/FAQ/1042256
You may also need to manually set the timings.
Be extremely careful with voltages.
1/10 of a volt (0.1) is a lot.
You can easily fry a part if it's over volted beyond what than the part can handle.
I went through this with my MSI X570 Unify motherboard.
I also had to disable the "Check if Memory changed" during boot check so I could get 4 32GB RAM cards to boot at 3200MHz.
Have you run any diagnostics on the memory? Might just have a bad stick.
That's funny I underclocked my CPU for rendering. When I built this system the CPU started at 4.8ghz liquid-cooled would thermal throttle the CPU. Dialed back until it started hitting mid-80s C while rendering.
You can manually set your RAM memory speeds in your BIOS if it will not automatically boot with XMP enabled (I had to do this on my system when I upgraded from 32 to 64 GB of RAM). I had a similar issue to you on my system--my MB has 8 DIMM slots and when I had 4 RAM sticks (4 x 8 GB DDR4 3000 from G-Skill) the XMP would work and automatically boot to 3000 MHz. When I added 4 more 8 GB sticks the XMP would not enable and the system booted to 2133 MHz with all 8 sticks. I manually set the RAM to 3000 MHz and adjusted the timings in my BIOS and everything boots fine with the manual overclock.
Yeah, I slightly undervolt my ryzen too, keeping it cool helps a lot.
Thanks for the on-spot replies. There might be hope.