[Sammelthread] Samsung 8Gbit DDR4 C-Die K4A8G085WC - OC-Ergebnisse im Startbeitrag! [updated]

[alxns]

@Blast I can change those voltages but I have big doubts about the board actually changing anything, i.e. just autocorrecting. I've seen results with impedance though. You said you can change procODT. Can you change RTT and CAD as well?

 

[alxns]

Sieht gut aus! Hab es im Startbeitrag ergänzt.

@emissary42 Kleines Update... Das war leider nicht 100% stabil. Ich hab gesehen, dass ein WHEA warning während dem TM5 Test gemeldet wurde. Es sieht nicht so tragisch aus aber die sind wie "hidden BSODs".

Eigentlich hatte ich relativ viele WHEA Fehler, auch wenn Idle!

Ich habe also jede WHEA Meldung vom Windows Event Viewer ins Log eingetragen und versucht eine Lösung zu finden, ohne die Timings zu ändern. Oft kommt der WHEA Fehler bevor der Test seinen ersten Fehler meldet. HWinfo zeigt sofort, wenn solche WHEA Warnungen erscheinen.


Nach schlechte Erfahrungen mit Impedanz und VDIMM Änderungen, habe ich gesehen, dass es vielleicht am VSoC liegt (siehe Hardwareluxx RAM OC Anleitung)
Geändert: VSoC 1.100>1.125V, SoC LLC mode 2>4 also mehr Vdroop bei MSI
Die Spannung hat sich also mit dem gewünschten 1.100V angenähert. Gemessen:

VSoC idle:    SVI2 TFN:1.10625V
            DMM:VRout 1.125V socket 1.105V
VSoC load:    SVI2 TFN:1.10625V
            DMM:VRout 1.130V socket 1.100V

Früher hatte ich Load VSoC 1.082V am Socket

Ergebnis ist viel besser. Hier 20 cycles TM5, 1Std Prime95 Large FFT, und 1Std AIDA. Keine Fehler oder WHEA warning.

Log aktualisiert

Hier wurden auch procODT/RTT/CAD und VDDG angepasst, sowie tRDRD_/tWRWR_, die möglicherweise mit 'Auto' zu tief waren. Aber schlussendlich war hauptsächlich VSoC schuld bei mir.
tRFC ist tiefer sogar (612>594). Können die anderen Timings auch tiefer werden? hehehe

Ihr könnt versuchen, die Spannung ebenso einzustellen und sehen ob ihr stabiler werdet. Es hängt natürlich viel vom Mobo ab. Das hat bei mir funktionniert, kann aber bei euch anders sein.
Der SVI2 TFN Sensor ist zuverlässig aber leider ist die Auflösung nicht ganz gut. So sieht es während AIDA Load aus (avg 1.10625V mit kurzen Schwankungen min 1.10000V max 1.11250V)


Es *KANN* auch sein, dass wenn VDDG 'Autocorrected' wird, ist der Wert nicht richtig erreicht, da VSoC etwas zu tief ist. Leider weiss ich nicht genau, wo mann es messen kann. Und wie genau es überhaupt generiert wird.

 

[emissary42]

Ich hab das Update leicht gekürzt in den Startbeitrag mit eingefügt

 

[Operation.Void]

Hey emissary42! It's me u/SheepishCombozZ from reddit, finally got an account to offload all of my findings onto this thread. Sorry for no German, I can't read nor write it. Thank goodness Chrome has a built in translator!

- tRFC ranges from 310-330ns on most kits, or 10.23-10.89 per 66MHz.
- tCL can't really get below 9ns as by the time you get close it starts to negative scale.
- My kit negatively scales at around 1.43V. I'd consider it unsafe though, and say that ~1.35V is the sweet spot.
- tRTP bottoms out at 6 on most kits.
- tRCDWR has more headroom than tRCDRD.
- tRP can most of the time go 1 tick lower than tRCDRD and sometimes more.

With that out of the way here are my final OC results (updated since last message) which are tight as can be:

I haven't tested very thoroughly, but after hours of gameplay I haven't encountered a single issue with these timings. I almost got CL17 (also tried 2T to no avail) but it would've required around 1.4-1.42V which is a bit too much for C-die. I've also done 3333 16-19-19-19-35 and 3200 15-18-17-17-34 without issue.

 

[emissary42]

Hi there and welcome to Hardwareluxx

I know you are already tweaking your settings for a good while and even if CL17 didn't happen in the end, they are still looking pretty good especially considering the value kit and your B350 motherboard. Your findings seem on par with the results of other users, where going above 1.4V can be hard to fully stabilize, if it is very close to the point where the kit stops scaling.

Also don't worry about writing english in the forums, most of us can handle that just fine (even without a translator^^).

I'll add your result to the first post. If you want to add screens for 3333c16 and3200c15, just go ahead

 

[alxns]

hey @Operation.Void ! thanks for sharing

- tRFC ranges from 310-330ns on most kits, or 10.23-10.89 per 66MHz.

So lately I've done some testing and reading on that and it's heavily temperature dependant. There's no magical formula, unfortunately. tRFC is related to charge refreshing which is one of the most power hungry DDR4 operation. C-die gets hot at lower voltages than other typical ICs, and when overclocking, it also can get unstable around 40 degrees C.

I was trying tight subs at 3800MT/s including tRFC 594. I was passing Karhu ramtest 20k% but could not get passed 10-20min of Testmem5. With Karhu the modules do not get as hot.
So, if you do something like that:

you might be able to go even lower. That 2100 RPM industrial fan allowed me to pass the 20-min wall I was having with TM5. 20 cycles 1usmus_v3 1hr30min no errors. For reference, temps dropped by 10 degrees.
Obviously you can't really have that fan setup daily, but at least I knew I had to get lower temps if I want to be stable all year round. Either by loosening some timings or having better case airflow.

- tCL can't really get below 9ns as by the time you get close it starts to negative scale.
- My kit negatively scales at around 1.43V. I'd consider it unsafe though, and say that ~1.35V is the sweet spot.

Probably because it gets way too hot for any normal operation haha. Plus, I don't think your kit has any heatsinks if I'm not mistaken? I used to try 3600CL16 which needed 1.41V but never could get it 100% stable. Now I know why 😅 Very little stable voltage window.
What has worked for me was testing highest possible voltage that passes AIDA mem stress (1.34V for me), then lowest possible voltage that quickly throws errors in memtests (1.32V), and take the middle point (1.33V).
I'd be careful with 1.35V even. Not unsafe, just might get unstable in the summer for example.

- tRTP bottoms out at 6 on most kits.

The lowest setting is 5 as per JEDEC and if you have Geardown ON, tRTP has to be even, so that's why. Also, tWR and tRTP are supposedly set with the same adressing bits in the DDR4 mode registers, with tRTP always being half of tWR. What I suspect is, if any of the two settings don't match the JEDEC mode register and Geardown spec, it will autocorrect. I also suspect Ryzen Master and ZenTimings only show what is set in the BIOS, so it's hard to say what the reality is without some proper testing. But those are minimum timings anyway, not absolute.

I don't bother and just always set tWR+tRTP together which has worked fine so far.

With that out of the way here are my final OC results (updated since last message) which are tight as can be:I almost got CL17 (also tried 2T to no avail) but it would've required around 1.4-1.42V which is a bit too much for C-die. I've also done 3333 16-19-19-19-35 and 3200 15-18-17-17-34 without issue.

I've tried Geardown OFF 2T for the odd CAS numbers but to be honest it just caused more issues at higher frequencies 🥴

Try also to increase you SoC voltage, it seems on the low side. Could get you some sneaky instability.

 

[Operation.Void]

I have a very standard airflow setup, a decked out Versa H18 with all fans but rear exhaust (1200rpm) spinning around 800rpm with molex 7V mod. You are correct in saying my kit has no heatsinks but there is an exhaust directly above it, not intake because it will suck dust in which is not cool. Changing SOC voltage doesn't seem to help anything either. My numbers are probably a bit off because I haven't done extensive testing and am just going of what I noticed when OCing. I believe 3666CL17 would be achievable at around 1.38V on these kits, and it would yield good memory performance but for me as a Ryzen user the higher FCLK is more important.

And @emissary42 I don't have any screens of those unfortunately and I may or may not have... overwritten the profiles in my BIOS 😮.

 

[emissary42]

War gerade dabei nach verfrühten B550 Reviews zu schauen und bin dabei über einen weiteren C-Die Test gestolpert:

Transcend 2x TS2666HLB-16G (2x16GB) @ coolaler (johnuahuang)



Das OC-Ergebnis von DDR4-3500 CL19 ist aber in Anbetracht der verwendeten Hardware nicht gerade beeindruckend^^

 

[Operation.Void]

Hey their JEDEC #11 is exactly the same as mine. I wonder what voltage they did this at, it seems like this was done at 1.2V as they didn't specify any changes to it.

 

[alxns]

You are correct in saying my kit has no heatsinks but there is an exhaust directly above it

That greatly helps! My 10-year old case is a problem, no exhaust possible directly above it, just off by 15mm I need to add a 140mm fan there...

@emissary42 danke. Diese chinesischen Reviews sind immer soo detailliert und haben so schoene Fotos 😋

 

[Operation.Void]

It seems my time overclocking the RAM has come to an end. 😭

I just tried tightening every timing I could by 1 tick and all returned errors. I can't shoot for higher frequency as FCLK does not go any higher than 1866MHz. SOC 1.2V, VDDP 1V and VDDG 800mV don't help.

 

[emissary42]

Oh don't worry, the next bios update might make you start over again... if you ever dare to make the switch

 

[Operation.Void]

Oh don't worry, the next bios update might make you start over again... if you ever dare to make the switch

Oh no...

I got VDDG and VDDP down to 750mV stable so I guess that's a win.

Edit: 775mV VDDG and 875mV VDDP, spoke to soon!

 

[alxns]

Hab einen kleinen 80mm Ventilator installiert. Viel besser!

 

[Operation.Void]

You can try getting tWTR_L lower, tCWL lower and tRC lower. I think you could do tWTR_L 8, tCWL 16 (will need to change tRDWR to 9) and tRC 65.

 

[alxns]

Will do! Although I don't think tRC goes any lower... 67 perhaps but 66 is a no-no 😋
I'd like to work on VDDP/VDDG CCD first, I never really tested the lower limits

What are your "rules" for tRDWR/tWRRD? Really unsure on how to set those.

 

[Operation.Void]

Your tWRRD is already good, mine is at 2. I believe it's tRDWR and tCWL that need to equate to a certain number, for you probably 26 so tCWL 16 and tRDWR 10 is ideal from what I've heard. I could be very wrong, there is possibly a tie between tWRRD and tRDWR rather than tRDWR and tCWL.

 

[Cpt_cool]

kleines update : dank der hitzewelle (+6 Grad und mehr im Vergleich zum Vormonat) wurde mein OC instabil xD Was vorher bei 3733mhz 1,33v von 3200mhz - 2h+ stabil bei Aida64 lief, schafft nun kaum noch 20 Minuten
Kühlt ihr eure Dimms aktiv ? Würde mich über Bilder freuen

lg

 

[Operation.Void]

@Cpt_cool I have the AMD stock cooler and a 1200rpm 120mm fan up top as exhaust (modded 7V, so like 800rpm). Also 3 front intakes also 7V all 800rpm. Lucky for me my room has air conditioning so I don't need to worry about heat waves too much .

 

[alxns]

@Operation.Void Oh having a vertical mount cpu cooler must help a lot too! Is that a thermaltake case?

@Cpt_cool My cpu cooler sucks all the air coming from the front so not ideal... I'm trying different configurations while trying to keep it quiet. I made a 80x15mm fan bracket above the DIMM slots and it helped a lot. Tried top exhaust but it doesn't really help as the DIMM slot below the tower cooler doesn't get fresh air anyway

 

[Operation.Void]

Yes it's a Thermaltake Versa H18. Incredible airflow, especially for mATX. I'm going to replace my CPU cooler with a be quiet! Pure Rock 2 at some point, we'll see how this plays out with my OC.

Update: Switched around my fan. So the 1200rpm (highest speed, but higher quality so quieter) fan is intake over my DIMMs from the top with a mesh filter and it seems to be stabilizing my previously unstable OC! Samsung C-die is very sensitive to temperature, just a 3c ambient change and poof my OC is unstable.

 

[Cpt_cool]

Danke für die Bilder !

Falls euch der Performanceunterschied zwischen Stock und OC interessiert :
Testsystem : R 5 3600X , 16gb Ram, MSI B450 Pro MAX , KF2 Geforce 2060 super @ stock (Treiber 442.74)

Far Cry 5 Benchmark max details , no HDR textures, full HD resolution

Stock (3200mhz 16 18 18 34 75 : 6450-6500 frames / Time Spy CPU : 7150 - 7200
3200mhz 15 17 17 32 54 : 6700-6750 frames / Time Spy CPU : 7300-7350
3733mhz 18 21 21 43 72 : 6700-6750 frames / Time Spay CPU : 7300-7400


GTA5 profitiert meinem empfinden nach noch etwas mehr von Mhz als von Timings (2-4%) , habe aber keine belastbaren Ergebnisse dazu.

 

[Operation.Void]

Thanks for the pictures !

If you are interested in the performance difference between floor and OC:
Test system: R 5 3600X, 16gb Ram, MSI B450 Pro MAX, KF2 Geforce 2060 super @ stock (driver 442.74)

Far Cry 5 benchmark max details , no HD textures, full HD resolution

Stock (3200mhz 16 18 18 34 75 : 6450-6500 frames / Time Spy CPU : 7150 - 7200
3200mhz 15 17 17 32 54 : 6700-6750 frames / Time Spy CPU : 7300-7350
3733mhz 18 21 21 43 72 : 6700-6750 frames / Time Spay CPU : 7300-7400


I think GTA5 benefits a little more from MHz than from timings (2-4%), but I have no reliable results.

Could've used much lower tRC and slightly lower tRAS on the 3733. Other than that this is a good comparison.

Edit: I'm not going to flood this thread... I did manage to tighten a few timings from my "final" OC. I got tRCDWR down to 19, tWRRD down to 1, and tWRWRSD and tWRWRDD down to 4. I couldn't get these timings stable because my initial OC wasn't stable due to temps. 🤦‍♂️

Sooo when I said I couldn't OC further, that was a lie. I did this at lower voltage (1.33V, in BIOS it is +0.144V offset) with tighter timings!

Update: Also ran HCI Memtest automated with DRAM Calculator for 600% (I know only 20 minutes but strapped for time) and it had zero errors. I can confidently say this OC is "stable".

 

[Cpt_cool]

@ Operation.Void
Haha NICE DUDE !!!!

Die Korrelation der Stabilität zur Temperatur vergisst man gerne, wenn man 20 verschiedene Parameter testet

 

[Operation.Void]

[USER = 306787] @Cpt_cool [/ USER]

Definitely easy to overlook. I'm surprised by my tWRWRSD and tWRWRDD which are quite low.

Edit: Gee wee every day my OC becomes unstable. Yesterday I have it at 1.33V stable, today I come and get lots of crashes and test with 3 errors in a minute. I bring voltage up to 1.34V and now it's stable again. WTF C-die?!

 

[Cpt_cool]

[USER = 306787] @Cpt_cool [/ USER]

Definitely easy to overlook. I'm surprised by my tWRWRSD and tWRWRDD which are quite low.

Edit: Gee wee every day my OC becomes unstable. Yesterday I have it at 1.33V stable, today I come and get lots of crashes and test with 3 errors in a minute. I bring voltage up to 1.34V and now it's stable again. WTF C-die?!

Ich verstehe es auch nicht Liegt es eventuell an den Temperaturen ? Anonsten könnte es sein, dass dein Ram wirklich sehr nah am Limit stand. Sowas ähnliches hatte ich mal mit einem Kaltstart mit bestimmten Timings. Sobald der Rechner eine gewisse Zeit lief, konnte ich anschließend im Bios die Timings runtersetzen und er lief stabil. Dies lief allerdings nicht mit einem Kaltstart bei den gewählten Timings.

Ich konnte heute ebenfalls meine Subtimings neu einstellen. Von 6-9-34 (stock) auf 4-6-23 ! Nun läuft mein Arbeitsspeicher in den Gamebenchmarks bei 3200mhz t1 15 17 17 34 54 + tuned subtimings schneller als mit 3733mhz t1 cl18 (sieht Beiträge oben) und leicht getunten Subtimings.
Bei 3733mhz konnte ich kaum noch die Subtimings ändern : von 7 10 40 nur auf 6 10 36. Auf Anhieb 7400 Punkte im Time Spy erreicht ohne irgendwie kühle Außenluft oder ähnliches durch das Gehäuse zu befördern. Diesmal konnte ich in Far Cry 5 6820-6850 frames erreichen.

Ich nehme an, dass ich wahrscheinlich auch mit 3733mhz noch wesentlich bessere Subtimings erreichen könnte, würde ich nur für die notwendige Kühlung sorgen.
Nach mehr als einer Stunde last unter AIDA64 erreicht mein Mainboard nun 34°C - 3-4°C weniger als bei vergleichbaren Außentemperaturen mit 3733mhz.

@Reous

Du hattest in einem Post erwähnt, dass mein Ram @3733mhz wahrscheinlich am Limit läuft und deshalb keine niedrigeren Subtimings drin sind.
Tja .. du hattest recht ! ;-) Es lag an den höheren Temperaturen, wodurch weiteres Tuning zu Fehlern führte. Diese traten dann auch erst spät in AIDA64 auf (ca. nach 20-30 Minuten).

 

[Operation.Void]

@Cpt_cool

My explorer.exe has been crashing all the time, IDM dll file and some other Windows one. I'm running AIDA64 now after having run TM5 and HCI to make sure it isn't RAM. I just reinstalled IDM and did some potentional fixes for ntdll.dll, very annoying!

 

[alxns]

@Cpt_cool ich kann empfehlen, weil du ein MSI Board hast, die neue AGESA 1006 (noch Beta allerdings aber soll bald als Final released werden) zu aktualisieren bzw die AMD Overclocking Override option für VSoC (und Vcore falls Manual OC) und nicht die normale Override Option zu benutzen.
Das hat einen Untershied für mich gemacht, da die Auto Einstellungen mit "AMD Overclocking Voltage Override" bei CPU Features oder z.B. LLC dann anders sind.
Worth a try!

Kannst du deine BIOS Settings teilen?

 

[Cpt_cool]

Hast du das Bios manuell oder über die MSI APP geflasht ?

 

[Krümel]

Hatte mit meinen DR-Riegel etwas gekämpft, die 3.600 wirklich stabil zu bekommen. Nach Tagen trat immer mal wieder ein Fehler auf.
Die Lösung war, wie oben schon angeführt, die Spannung von 1,35 auf 1,33 zu reduzieren, seit dem läuft das System sauber.