Anyone have DDR5 Samsung subtimings I can use?

[GrimReaper85]

Just something for the start. I read David Miller's OC guide, but he listed quite big ranges.
I have 6000 36-36-36-96 1.35V, should be one of the best if not the best Samsung. Voltage will be default 1.35V, I don't think it's worth it more just for the subtimings, plus they won't be active cooled. Still have to wait for AM5 to release, I will almost for sure not go Alder/Raptor Lake due to way worse efficiency.

Which timings are dependent on each other? I know with DDR4 there were some. Probably lowering all to the lowest (except tREFI) will not be a good idea.

Auto timings are supposed to be bad. So I'm not looking for absolute lowest timings, just something in the middle which Auto should be in the first place.

 

[Woomack]

David has the knowledge, but if I'm right, then his guide was based on barely 2 memory kits just after the premiere, and some things are more predictions than actual tips. I'm sure it would be more detailed if he had more kits and more time for that.

I was testing G.Skill 6000 CL36/Samsung kit. Actually, two of them, but one died before I pushed it some more. However, I have no list of sub-timings from my Samsung tests. As I remember, the G.Skill kit already had pretty good results considering it was only XMP, and setting higher tREFI (120-260k) was already giving high bandwidth/low latency. It still needed ~1.5-1.55V to run at higher clocks, and then it's overheating without good airflow like a direct fan.
All my current DDR5 kits are Hynix or Micron, as every brand uses Hynix for 6200+ kits and Micron for 4800-5200. The next two reviews will cover 6600 kits and are also Hynix based. I can only tell you that sub-timings on Hynix and Samsung are not so much different in DDR5. Hynix simply runs higher at lower voltages.

Focus on tRFC, tRRD L/S, and the best if you can manually adjust RTL. On my MSI motherboard, it's not working for some reason (whatever I set, it uses auto settings). Other secondary timings are helping less or don't help at all. Tertiary timings are not helping much. In the end, full timing table tuning gives 0-1% in overall performance, so I'm not sure if it's worth the hassle unless you need it for competitive benchmarking.
1.35V should still give you something like 6200 36-36-36, and high tREFI and low tRFC will put you somewhere near 100GB/s read, 90GB/s write/copy, and 60ns latency (looking at AIDA64). Full tuning will add 2-3GB/s bandwidth and lower latency by 2-5ns. So you have to ask yourself if it's worth it.

Rules about timings are about the same as in DDR4, and most are called the same way.
I have no idea how it will look on the new AMD as in DDR4 or earlier on DDR3, AMD was using a bit different settings, and some timings were also different than on Intel. For example, the tRC was available on AMD, and you can't set it on Intel. I have high hopes regarding the new AMD as Intel Z690 motherboards are pretty much a fail. On the other hand, somehow, I doubt we will get problem-free AMD motherboards. AMD cooperation with partners is on a low level, and everything is always delayed, so probably 3-6 months on various AGESA fixes before we get something good.

 

[GrimReaper85]

This will be of much help, if they don't work from the start, then at least as a baseline:

Corsair Vengeance RGB DDR5-6000 CL36 2x 16 GB Review

Corsair Vengeance RGB brings a competitive DDR5 kit, with an XMP 6000 MT/s profile and modest timings of 36-36-36-76. Designed to fit right into the Corsair ecosystem, it is time to take a closer look and see what all the fuss is about!

www.techpowerup.com

 

[Woomack]

This is as much help as you do it yourself, or even less.

 

[GrimReaper85]

Especially since I will most probably be on AM5, have to wait for reviews 2,5 more hours.
I don't like this very much anyway:

I caution against overclocking without a fan directly placed on the memory, or at least good case airflow. Otherwise, unexpected stability issues may occur as the memory warms up.

That being said, understand no overclock is guaranteed and stability issues may occur if the memory gets too hot. This was certainly the case here. Without a fan directly on the memory, system errors was not uncommon to see while working on the memory sub-timings.

This was the reason I have 4000 16-16-16-36 on XMP since end of 2021. It was quite some time memory OC worked for me, Micron DDR2, but only primaries. Both DDR3 kits I had on XMP, first one from beginning, second one after many BSODs with all subtimings lowered to min.
Every time you test memory stability, you also have to run at the same time Kombustor and Prime95 Small for CPU, it's a lot of work and stress for components.

Do you at least have any idea if some subtimings are not so heat sensitive? I think first 5 secondaries in ASRock configurator should be possible.

 

[EarthDog]

IIRC, so long as your at 1.45V or below, you won't need direct airflow. @Woomack has some thoughts in his experience where these start to crap out temp-wise.

 

[Woomack]

Especially since I will most probably be on AM5, have to wait for reviews 2,5 more hours.
I don't like this very much anyway:


This was the reason I have 4000 16-16-16-36 on XMP since end of 2021. It was quite some time memory OC worked for me, Micron DDR2, but only primaries. Both DDR3 kits I had on XMP, first one from beginning, second one after many BSODs with all subtimings lowered to min.
Every time you test memory stability, you also have to run at the same time Kombustor and Prime95 Small for CPU, it's a lot of work and stress for components.

Do you at least have any idea if some subtimings are not so heat sensitive? I think first 5 secondaries in ASRock configurator should be possible.

I bet you will wait for 3-4 months for a proper BIOS I also doubt that any popular website will show you any higher overclocking results. There are really few guys around the web who do that or see any point in RAM OC for motherboard reviews. RAM OC gives 0-1% overall performance gain, so some skip it to save time. Most simply have no idea how to do it. You won't find anything good on sites like TPU. They have good graphics cards or maybe PSU reviews, but that's all. Most good tips regarding RAM are on overclocking/enthusiast forums (most of them are dead), but it takes a lot of time to actually find good info. Like on OCN, you can browse various topics, but one post per 100+ is actually worth something.

CL/wCL and maybe 2 more are reacting faster to heat. It sometimes changes depending on the brand/specific memory kit. Like in my last reviews, V-Color could run at about 5°C higher than Corsair, keeping stability. In general, if you have good airflow in the case, then it's fine up to 1.45V, sometimes 1.50V.
RAM overheating happens almost only under full load. If you play games or do other, let's say, typical things, then at 1.45-1.50V, it will keep ~50°C. Most memory kits are losing stability at tight timings and 60°C+. Tight like CL32 or less. There are also differences between heatsinks, or some kits don't have thermal pads on PMIC.

 

[GrimReaper85]

I'm not having any luck with this Samsung kit.
Last thing I tried yesterday was XMP and Karhu errored after 17min, sticks were at 63.8°C.
Everyone talking about Samsung being hotter than Hynix, my first assumption was that the sticks are too hot to be stable.
Proof for this is also they needing to cool down to even get into Windows, I needed 5 resets to not get BSOD before Win, or I got into Win and sound stuttered.

I think my DDR4-4000 16-16-16-36 had the same temperature, but it just worked on XMP, even at 60°C, or was it even 65°C.
I had the same problem for them to cool down before i could get into Win, but that was after BSOD-ing from stress testing with all subtimings lowered to the min.

I think XMP should work in any case, G.Skill doesn't say you need active cooling.
Plus I also tried 4800 CL40 and same problem.

If nothing else, I will just have to buy some Hynix 6000 30-38-38.

Another problem is the BIOS, it is slow as hell. I have Aorus Master X670E. I read already Aorus X570 had problems and someone wrote you mustn't press DEL several times, just once. But there were at least 3 occasions already when I was pressing like crazy and it still went past that screen into Win.
I will try today if it really helps if you press once.

Another problem is I can't get IF 3000 MHz if I don't select XMP, but just manually selecting frequency and timings. IF is 1500 MHz if I set UCLK to Auto or UCLK=MEMCLK.
Why I even tried selecting manually is because I thought some XMP timing is Intel related, but I already tried and I didn't get any better stability with:
tRC - XMP 132, Auto 146
tRTP - XMP 12, Auto 23
tFAW - XMP 40, Auto 32 (actually lower than XMP)

Some still think EXPO is better for AMD, but I found a review of 6000 CL30 and timings are nothing special, same as XMP (screens towards half of slider):

G.SKILL Trident Z5 Neo DDR5 AMD EXPO 32GB-6000MHz C30 Review [Análisis Completo en Español]

Los nuevos procesadores Ryzen 7000 que llegan hoy a las tiendas vienen también de la mano de una plataforma más homogénea donde cada elemento clave de un PC personalizado ahora queda completamente abarcado por el ecosistema de AMD. Nuevos procesadores, nuevos chipsets y nuevas memoria DDR5 AMD

www.geeknetic.es

 

[EarthDog]

I have the Master too and any time it retrains, the boot is noticeably slower. That said, the platform does this, not just Gigabyte (some boards are better than others). I use GSkill 5600 sticks and KIngston 6000 with it successfully.

When you say you "tried 4800 CL40" that's just JEDEC specs, right? Nothing you set? And it still overheated? That's not right....did you confirm the voltage that was set?

 

[GrimReaper85]

This kit:

F5-6000J3636F16GX2-TZ5RS F5-6000J3636F16GA2-TZ5RS - Overview - G.SKILL International Enterprise Co., Ltd.

Trident Z5 RGB series DDR5 memory is designed for ultra-high performance on DDR5 platforms. Featuring a sleek and streamlined aluminum heatspreader design, available in metallic silver, matte black, or matte white, the Trident Z5 RGB series DDR5 DRAM memory is the ideal choice to build a...

www.gskill.com

Boot I know it is normal to be slow, at least with current BIOS-es, or it might be forever, who knows.

But my BIOS is also slow, moving with keyboard arrow keys, and mouse is very sluggish also. It's not always the same though, sometimes it is normal fast, two times it even froze completely.

 

[EarthDog]

Have you tried reflashing the BIOS?

When you say you "tried 4800 CL40" that's just JEDEC specs, right? Nothing you set? And it still overheated? That's not right....did you confirm the voltage that was set?

EDIT: Doesn't the Master have voltage read points? Can you confirm what the bios says is what the sticks are getting?

 

[GrimReaper85]

I have latest BIOS F8a from the start, 8th October.

4800 CL40 is JEDEC, yes, with Load Optimized Defaults. I checked voltage, it is 1.1V.
I remember it was said higher voltage is even better if sticks overheat. I don't mean 1.5V, but 1.2-1.35V.

Today I already planed to try also 4800 CL40 with HWiNFO opened. I actually did that yesterday, but it BSODed after 9min and I didn't check temperature before that.

Very strange things are happening indeed. Usually when that is the case, it's good for RMA. Beginning of year I also struggled with 6900 XT stability, but card was just not good.

But they do work normally when cool, only Karhu makes them BSOD. So I still think Samsung is just crap with DDR5 if not actively cooled.

 

[EarthDog]

Did you reflash for giggles? Does the slow bios movements happen only when the sticks are 'hot'?

But they do work normally when cool, only Karhu makes them BSOD. So I still think Samsung is just crap with DDR5 if not actively cooled.

I never heard of it until this thread....but I'm not a memory guru either.

No issues with my 5600 sticks without cooling. They'll do your 6K timings/settings too. There's a problem somewhere... be it in the sticks/PMIC or something with the board.

 

[Woomack]

On ASUS, BIOS is also loading a bit slow but I can't really complain. On the web, some others report slow start after clearning CMOS or accepting new settings on some other X670/E mobos. ASRock fixed the slow start with new BIOS as I heard.

EXPO is nothing else than a profile that matches AMD specs. There are some single timings that are different, but most are the same as in Intel RAM. If you use XMP then it skips tRC and some other specific timings and the motherboard sets what it thinks is correct.

Your Samsung RAM should work at XMP/rated voltages without problems. If it's overheating at XMP or you have other problems, then make an RMA. I bet you get a replacement quite fast, and probably Hynix kit.

As I remember, you had to enable XMP on Gigabyte X570/Z690 too, to set everything manually. I don't remember exactly but I will test B650E Master soon (should be not much different than the X670E).

 

[GrimReaper85]

Did you reflash for giggles? Does the slow bios movements happen only when the sticks are 'hot'?

I already thought about that, I think in the morning BIOS is always fast. It was yesterday and today.

 

[Woomack]

There is also a possibility that when you turn off the PC and unplug the power, then during the next start, the motherboard is retraining the RAM. Check RAM options, and maybe there is something about retraining each time it starts or something else. It's only a quick thought, but retraining on Gigabyte takes ages.

 

[EarthDog]

I already thought about that, I think in the morning BIOS is always fast.

So that means..................they are cool?

But yeah, you did your due diligence, I'd RMA those sticks as something clearly isn't working right.

 

[GrimReaper85]

Yes, in the morning they are cool.

 

[GrimReaper85]

And which kit is actually better bin?
6000 30-38-38 (F5-6000J3038F16GX2-TZ5NR) - 325€
6400 32-39-39 (F5-6400J3239G16GX2-TZ5RK) - 304€

EDIT:
Non-RGB 6400 CL32 even 239€ in Mindfactory. I was looking at RGB only for easier resell.

 

[Woomack]

6000 CL30 and 6400 CL32 are using the same IC. My kits were about the same, both could make 7000 CL32 ~1.5V which was max in dual-channel for my motherboards.
Actually, the same results also had ADATA 6400 CL40, V-Color 6600 CL34, Corsair 6600 CL32, and some more. If you get it for AMD then it doesn't matter as up to 6400-6600 it will be exactly the same.