[SOLVED] Downclocking/Tightening timings from 4133MHz CL19?

[Barty1884]

Hi all,

I felt like tinkering with my system and bought a 2x8GB 4133MHz kit 19-25-25-45 Corsair Vengeance LPX, to replace my 2x8GB LPX 3200MHz 16-18-18-36.

Was more curious than anything else, and the 4133MHz appears stable with XMPII which reduces some elements from "auto" beyond the primary timings (not so much so with XMPI).

Long story short, appears to be liming my CPU OC (8086K @ 5.3GHz -2AVX, 1.33V LLC6) & I don't need 4133MHz, so I was looking to see if I could tighten up timings to maybe ~3600 CL14-15

1. Any guides or suggestions for this? Really not my area of expertise - and all the calculators for 'safe' numbers are Ryzen-only, AFAIK.

2. What's the easiest way to identify whether or not this kit is B-Die? Suspected it was based on the model numbers, but the XMP timings don't seem right to be (with my limited knowledge).

 

[DMAN999]

You can use Typhoon Burner to check and see what IC's it uses:
http://www.softnology.biz/files/thphn163.zip

Extract that and Run it as Administrator and then click on the Read Button and choose one of the RAM sticks to read.

 

[Barty1884]

Thanks @DMAN999

So, appears it is B-Die afterall.

 

[Barty1884]

3600 15-15-15-36 appears stable. Will need long term testing to verify, but I just slapped in 3200MHz at those timings and appeared good, worked up to 3600. 3800 will pass CB a couple of times but crashes eventually, so assuming 15 or 16 should be doable at 3600 (or 3733/3800 with a voltage bump).

 

[DMAN999]

Nice.
Have you run any Memory tests yet like Memtest64 or HCI Memtest (with Memtest Helper) ?

 

[Barty1884]

Nice.
Have you run any Memory tests yet like Memtest64 or HCI Memtest (with Memtest Helper) ?

I ran a single pass of MemTest64, just to make sure there was no glaring issues. Full blown stability testing likely won't be able to happen until the weekend.

I tried HCI within Windows, but screenshots didn't align with what I saw (in terms of setting cores/threads instances)..... and it kept giving me "couldn't allocate 4095".

 

[Barty1884]

Prine95 Custom w/ ~15GB loaded has been running for a couple of hours & no errors thus far. 3600, 15-15-15-36

 

[Barty1884]

Left PRime running overnight at 15-15-15-36.... checked back ~12 hours and the system had restarted

 

[DMAN999]

Left PRime running overnight at 15-15-15-36.... checked back ~12 hours and the system had restarted

That sucks, But RAM OCing / Tuning can be a time consuming task.
Just keep at it and I'm sure you will find some settings that are stable and satisfy you.
Remember, Slow and Steady wins the race.

 

[Third-Eye]

Left PRime running overnight at 15-15-15-36.... checked back ~12 hours and the system had restarted

HWInfo shows extended XMP settings not exposed to the BIOS, so you could probably grab timings from there that are looser than 15-15-15. You will probably need to calculate your own tRFC or use a lower value the BIOS calculates, to tighten it more than the highest tRFC the BIOS would usually use, if you use automatic for tertiary timings.

I am far from an expert on ram and ram timings, but from what I can tell in pictures, your CMK16GX4M2K4133C19 uses A0 PCBs (which could be wrong), so you probably won't get better than 3600 CL15 without extensive tweaking. More likely you will have to settle for 3600 CL16-16-16-36.

 

[Barty1884]

That sucks, But RAM OCing / Tuning can be a time consuming task.
Just keep at it and I'm sure you will find some settings that are stable and satisfy you.
Remember, Slow and Steady wins the race.

Oh definitely. And this wasn't something I expected to be one & done.... always looking for something to tinker with and I don't see any further hardware upgrades in the near future, so this gives me something to mess with (and try to combine with my CPU OC).

HWInfo shows extended XMP settings not exposed to the BIOS, so you could probably grab timings from there that are looser than 15-15-15. You will probably need to calculate your own tRFC or use a lower value the BIOS calculates, to tighten it more than the highest tRFC the BIOS would usually use, if you use automatic for tertiary timings.

I'm still doing my research, as RAM overclocking really isn't my area of expertise - especially secondary & tertiary timings. tRFC as per XMP/MB is 724 (and this kit is on the MB QVL!) which, as far as I can tell is a pretty ridiculous default?

I am far from an expert on ram and ram timings, but from what I can tell in pictures, your CMK16GX4M2K4133C19 uses A0 PCBs (which could be wrong), so you probably won't get better than 3600 CL15 without extensive tweaking. More likely you will have to settle for 3600 CL16-16-16-36.

You may well be right, I'm not 100% sure. The screenshot would suggest so, but gather that isn't always 100% accurate. Short of removing the headspreaders to confirm config/layout, I'm not sure if there's any other way to verify.

Regardless, if I can get to 16-16-16-36 with 3600MHz, that puts me on par with my older kit @ 3200MHz that wouldn't budge down in timings or up in clocks.... So still a net positive, at least in theory.

 

[DMAN999]

Oh definitely. And this wasn't something I expected to be one & done.... always looking for something to tinker with and I don't see any further hardware upgrades in the near future, so this gives me something to mess with (and try to combine with my CPU OC).

I'm still doing my research, as RAM overclocking really isn't my area of expertise - especially secondary & tertiary timings. tRFC as per XMP/MB is 724 (and this kit is on the MB QVL!) which, as far as I can tell is a pretty ridiculous default?

You may well be right, I'm not 100% sure. The screenshot would suggest so, but gather that isn't always 100% accurate. Short of removing the headspreaders to confirm config/layout, I'm not sure if there's any other way to verify.

Regardless, if I can get to 16-16-16-36 with 3600MHz, that puts me on par with my older kit @ 3200MHz that wouldn't budge down in timings or up in clocks.... So still a net positive, at least in theory.

Yeah tRFC of 724 is high.
My 3600 C16 Hynix DJC kit has tRFC at 630 in XMP at 3600 but I got it down to 489 at 3600 and 504 at 3733.

And honestly with those timings, those look to be the lower binned B-Dies.
I have those on my G.Skill TridentZ RGB kit (F4-3200C16D-16GTZR) that I use in my R5 2600 rig.

https://imgur.com/4iAwun3

View: https://imgur.com/4iAwun3

They did not OC well for me, the most I could get was 3400 on the B450-F with that 2600.

So you may end up with something closer to the Hynix DJC timings on my 3700x rig:
G.Skill Ripjaws V (F4-3600C16D-16GVKC) @ 3733 MHz 16-19-19-19-36-56 (tRFC at 504)