Help! overclocking my Corsair Vengeance LPX DDR4-3600 C18 on msi x570 tomahawk wifi

[PotatoPopcorn]

Hey beginner OC’er here. Been fiddling around with the basic stuff for CPU overclocking in msi x570 tomahawk wifi. I managed to have it pretty stable with 4,7 ghz on ryzen 5700x. However id like to compliment it with some better RAM Speeds. I mean I built this thing so why not try and get the most juice out of it?

I recently upgrade my ram from a pair of Corsair vengeance 2x8GB 3600 mhz cl18 with pair of Corsair vengeance 2x16GB 3600 mhz cl18. They’re as close to the same types of ram as I could get from the shop.

Corsair Vengeance LPX DDR4-3600 C18 BK DC (AMD optimized) - 32GB - CMK32GX4M2Z3600C18
Corsair Vengeance LPX DDR4-3600 C18 BK DC (AMD optimized) - 16GB - CMK16GX4M2Z3600C18

 

After reading some of the basic stuff around it seems my setup is turned out to be a mix of two single rank sticks (2x8GB) and two dual rank sticks (2x16GB). I want to use them all together but wondering which setup would be best on my motherboard which is daisy chained. Currently I have them in pair where I have single ranked in A1-B1, and dual ranked in A2-B2. Seem to be stable with XMP profiles.

 

 What Is the best setup for performance and overclocking, would setting one dual rank and single rank together be better?

Is there any hope to get these bumping up to 4000mhz with cl16? So far Ive managed to get 3800 mhz cl18 (same tightnings as factory) with the msi memory try it! while pretty unstable with gaming and vm, but everything else leads to a cmos reset. Havent tried to manual set it yet.

[PotatoPopcorn]

[BiotechBen]

5 minutes ago, PotatoPopcorn said:

Try taking the voltage up to 1.37, and then 1.4. those LPX dimms love voltage (I have a set)

[PotatoPopcorn]

Nice, thank you ill try it! 

 

[PotatoPopcorn]

@BiotechBen By the way did you manage to reduce latency with yours?  kinda stuck at cl18 and it doesnt like me reducing those number even by just 1 without denying to post.

[RONOTHAN##]

I want to point out that this is one of the more cursed memory setups you can get for memory overclocking. If you haven't done it before, I really wouldn't recommend starting out by doing it on a triple rank setup with mixed memory. If you want to try doing memory overclocking, pull the single rank sticks and only try doing the dual rank sticks, that will save you a ton of headaches down the line. If you really need 48GB of RAM, I'd argue you shouldn't be doing memory overclocking in the first place since you're likely a workstation user where stability is more important than the 5% extra performance you'll gain from this. 

 

Anyway, as for some tips for how to do this, you want to figure out what's actually on those DIMMs. Just because two DIMMs have the same model number doesn't mean they're actually the same memory contrary to popular belief. There are half a dozen different memory chips that can be found in that particular speed bin, and all of them behave very differently when trying to overclock them. Some do not scale past 1.35V, others scale to 1.6V with ease, so your first goal is to figure out what the actual memory chips on each of those sticks. There are two methods of doing this, downloading a program called Thaiphoon Burner and reading the SPD or just pulling memory sticks and looking at the version number on the label. Looking at the version number is probably the most reliable, so pull those sticks out, look on the sticker for something that says something like "ver. 3.34" or "ver. 4.32" and just google "Corsair version x.xx" and see what the memory chip comes up. 

 

Once you know what memory IC you've got, odds are you'd also find a few people posting screen shots of what their memory overclock they achieved with it, so you can likely just copy those settings. If you don't want to do that or have a memory chip with a lot of variance in it, set the voltage that people generally recommend for it (for the most part it's something like 1.45-1.5V if you aren't gonna have active cooling, though there are chips that you want to set at 1.35V or 1.4V for optimal overclocks), loosen out the primaries and try to get the max frequency you can. You might be able to get something like 3800MT/s and max out the infinity fabric, you might not be able to go above 3600MT/s, so keep that in mind. When at those particular settings, you then want to start lowering the primary timings until you stop being able to POST. With the way AMD has their memory controller setup, there are a lot of timings that do not run at odd values, tCL and tCWL are the two that come to mind immediately. You can change that by disabling gear down mode, but it helps so much with stability that you realistically should have that enabled and just pretend that any 2 digit timing can only be set to even values with the exception of tRCD, tRP, tRAS, tRC and tRFC. Go through the primary timings, get them as low as you can, then run a stress test. After them, go through the secondaries, lower them as much as you can, then run a stress test. Finally, go through the tertiaries, lower them as much as you can, then run a long stress test for the entire memory overclock, and you're done.