SPD above 2133

[mackerel]

Some random thinking... are there any/many desktop DDR4 modules that program SPD speeds above 2133? That is, not requiring XMP to achieve it? The ram in my laptop does have SPD to 2400, which is all that is supported by the CPU. That got me thinking, I've not seen that on any of the various desktop modules I have. So I'm asking the wider community if anyone has seen such?

My thinking is simply that CPU official supported ram speeds are going up. Right now if I have fast ram modules, I can run SPD at 2133, or XMP at whatever the module is rated at, without having to pick speeds manually. Just thinking it would be nice if the bios had a setting that runs at max CPU supported speed inspired by XMP if greater than SPD, or better yet, SPD data for those higher speeds.

If I look back to DDR3 as a parallel, I think my early modules tended to be 1333 SPD, XMP 1600. Amongst the last DDR3 I bought were Kingston HyperX sticks, which were SPD to 1866, which makes them easier to use in non-OC mobos.

 

[Johan45]

I can't be certain but pretty sure I have seen some kits that default to 2400

 

[Woomack]

HyperX Predator 4000 C19 from my last threads have Samsung B at DDR4-2400. Crucial is selling DDR4-2666 Micron IC ( Ballistix Sport 2666+ ).
In theory in mass production are IC up to 3200 but I haven't seen any above 2666 in desktop memory kits. Actually all new servers that I'm selling recently have DDR4-2666 so also nothing higher.

There are a couple of reasons why we see mostly DDR4-2133 IC. One of them is that operating timing range is different. Another one is how IC is scaling with voltage. So based on Samsung B example, 2133 IC can make tighter timings and easier runs at CR1 at higher clock but in theory won't run at so high clock as 2400 IC. 2400 IC requires lower voltage for higher clock in my experience but can't run at tight timings and at least on my memory I can't even boot it at CR1 at 4000+.
Higher frequency IC is a matter of memory evolution. It always goes into higher base frequency and higher capacity but lower voltages. In the end there are various results but usually more relaxed timings, higher max frequency and lower voltages requited to achieve that higher frequency.

 

[mackerel]

I've tried to read Woomack's reply a few times but still don't get it

Maybe we have a different view here. When I say SPD I'm assuming the timings will be JEDEC standard. Anything non-standard can stay in XMP. I'm just wondering if we have enthusiast kits rated 3200+, why they can't also be SPD to 2666, 2933, 3200 for example. The timings will be much looser than typical XMP but it will also more likely "just work" in any random mobo. This should help those with non-OC mobos. For example, say someone got a system with i7-8700 (non-k) with non-OC mobo, they might get 2666 XMP ram but then be limited to 2133 SPD.

 

[Woomack]

I've tried to read Woomack's reply a few times but still don't get it

Maybe we have a different view here. When I say SPD I'm assuming the timings will be JEDEC standard. Anything non-standard can stay in XMP. I'm just wondering if we have enthusiast kits rated 3200+, why they can't also be SPD to 2666, 2933, 3200 for example. The timings will be much looser than typical XMP but it will also more likely "just work" in any random mobo. This should help those with non-OC mobos. For example, say someone got a system with i7-8700 (non-k) with non-OC mobo, they might get 2666 XMP ram but then be limited to 2133 SPD.

Check IC manufacturer docs. Here is example and maybe you understand this way. I don't remember now ranges of timings etc but let's say it's like this so will be easier.
2133 with range of CL between CL10 and CL20 - SPD compatible with JEDEC is CL15-15-15 at 2133
2400 with range of CL between CL14 and CL24 - SPD compatible with JEDEC is CL17-17-17 at 2400
2666 with range of CL between CL16 and CL26 - SPD compatible with JEDEC is CL19-19-19 at 2666
3200 with range of CL between CL18 and CL28 - SPD compatible with JEDEC is CL23-23-23 at 3200
It's not really correct but just to let you imagine that.

So if you want to make 3200 CL14-14-14 kit then you probably won't take IC which has the lowest value of CL14 in the table but 2133 which has lower range. The same if you want to make memory kit which will be stable at higher frequency and assume that in the worst case it won't boot at XMP settings then you take higher frequency.

When you try to boot at auto settings at 4000+ then motherboard will set something like CL21-25-25 using memory with JEDEC/SPD of DDR4-2400. When you use 2133 then probably it will boot at something like 19-21-21. It's also not correct but to let you know how it works.

Memory kits have something like timing tables. Memory won't even boot if you set too high or too low values. Upper CL is usually not a problem but some IC with SPD 2133 won't even boot above CL21.

Now something worth to know. Overclockers are looking for memory based on Samsung B-die. B is not telling us much as it can be something with SPD 2133 or 2400, it can be something that will overclock up to 3600 or something that will make 5000+. Depends on memory manufacturer, in use can be any IC that meet their XMP specification.
Because of various IC, brands like Corsair are selling most memory kits at relaxed timings so they can replace IC when will be shortage and memory kit will be still on the market. I mean all these 3000 CL15-17-17 or 3200 CL16-18-18 kits. The same are doing most brands.

Based on Micron I can say that each their new IC is overclocking higher at the same voltage. Their IC with 2666 SPD can make 4000+. 2400 SPD could make about 3600, 2133 SPD usually not much more than 3200. About the same is with Hynix. Samsung is a bit different as there are a couple IC under B-die naming and not all are equal if we look at overclocking.

So I think that the reason why we don't see IC higher than 2666 in gaming/enthusiast memory series is because it's not overclocking well at tigher timings and that are end-users expecting.
Probably there are also larger amounts of already binned IC or simply IC with known higher and lower ranges, tested on various platforms so memory manufacturers don't want to waste time and money on checking every possible IC when their product is meeting market demands.
Multiple times memory manufacturers were asking me not to show used IC in review, if memory kit was new and they used IC which wasn't popular on the market. It's because they made some work to find this IC and its working ranges and competition could see how it works and use it too. In the end it's hard to hide something like that.


I don't know how to explain it another way

 

[mackerel]

I haven't had a coffee yet. If I get it now, in essence there can be some kind of conflict between SPD timings and what you set XMP to? A certain speed IC has a certain timing range, and if the SPD and XMP are too different, that might cause problems?

 

[Woomack]

Memory manufacturers are matching available IC to their products and XMP profiles.
There are brands like Crucial or Kingston where you won't find anything close to the timing range of the IC. I mean they are using relaxed timings which are almost always in the middle of timing table range. So if you see 3000 kit from Crucial then (except Elite series) will have even more relaxed timings than we may expect so for example CL17. Used IC has SPD 2400 or 2666 so something like CL13-CL26 range. Just one example but as you see, there is no way that XMP won't fit there.

The only exception which I remember was one Corsair kit at CL10 where used IC supposed to have timing table starting from CL10. It still should work but CL9 won't be possible and if motherboard has some problems at tight timings then XMP won't work.

There are memory series like Kingston Fury or Impact where SPD=XMP. As long as motherboard supports higher memory clock, it will always run at rated speed, no matter if you use SPD or XMP.

There is one more thing. Look at diagnostic software. Something like AIDA64 or Thaiphoon Burner will show you longer table of frequencies and timings programmed in memory. There you can see how memory will boot when you pick higher frequency without enabling XMP. Motherboard can affect that too so it's not a rule it will work like that.

SPD is always compatible with JEDEC standards. Problems can be only with XMP profile if it wasn't tested right.

 

[mackerel]

Maybe I didn't ask the question right. Latest Intel CPUs officially support 2666 speed, and AMD support 2933. Are we saying there are no ram modules out there that could be purchased and put in a mobo, without going into the bios and manually enabling XMP (if even available e.g. non-OC chipsets), and work at that speed? I don't care timing will be the more relaxed JEDEC standard values to be safe. To my understanding, this would require the speeds to be entered in SPD, not just XMP. JEDEC speeds are defined to 3200. If the modules support tighter timings in XMP, that is a secondary factor.

 

[Woomack]

You can find OEM modules rated at 2933+ but it's not so easy to find them in stores. You can also pick one of the series which guarantee rated frequency out of the box, without XMP profile as long as motherboard supports that. As I mentioned, one of the only memory series like that for desktops is HyperX Fury which is available up to 3466 and its SPD profile is set to 3466 even though memory IC wasn't designed for that.

If you wish to play with that yourself then on some chipsets you can edit memory profiles yourself using something like Thaiphoon Burner software. There you can separately program SPD or additional XMP profiles. So in theory can upload profile from 4500 memory kit into SPD of 3200 kit and as long as IC will handle that then it will boot without enabling XMP at these 4500.


Here is Samsung memory IC/modules list. Some are at 3200 and are in mass production:
https://www.samsung.com/semiconductor/dram/ddr4/

The same lists can be found for Micron and Hynix.

 

[EarthDog]

Just a quick side note...AMD's 2933 is a max rating. Intel is a base spec.

 

[mackerel]

Just a quick side note...AMD's 2933 is a max rating. Intel is a base spec.

Is that the case? I thought they were both max officially supported speeds. That is, above that, you're on your own.

 

[Woomack]

AMD website suggests that 2933 is supported memory on Ryzen so I see no difference between Intel's 2666 and AMD's 2933, both look like guaranteed speed at which can work IMC:
https://www.amd.com/en/products/cpu/amd-ryzen-7-2700x
https://ark.intel.com/products/126686/Intel-Core-i7-8700-Processor-12M-Cache-up-to-4-60-GHz-

Intel has it as "Memory types: DDR4-2666"
AMD has "System Memory Specification 2933MHz System Memory Type DDR4 Memory Channels 2"

 

[EarthDog]

I may have been confused reading an Anandtech article where in their specs page they list it as MAX.

On AMD platforms, does it default to 2933 as a base spec like the INtel's do at 2666? This also shapes my thinking (AMD defaults to a lower speed).

EDIT: Perhaps I am entirely confused and in need of caffeine.

 

[Woomack]

On Intel there is chipset restriction. Non-Z chipsets can't work with memory above 2666. On AMD even the cheapest boards run at 3200+.

 

[EarthDog]

Not sure I get the relevance.

I'm asking if AMD defaults to lower than the 2933 they mention. Intel boards default to 2400 or 2666 depending on the platform...but of course runs faster. I'm saying the same for amd. By default to amd platforms START at 2933 on boot?


....still pining for caffeine I think, lol.

 

[Woomack]

There is no default speed in general meaning. IMC is rated at 2666 max for Intel and 2933 for AMD. It's like they say it will work up to this frequency and above that they won't guarantee anything. So default can be anything between minimum motherboard setting and IMC rated speed without overclocking. I don't know how to describe it other way. It's just like there is no one default frequency but range up to max IMC rated frequency. For Intel it's still more like if you don't have chipset designed for overclocking then it will run at mentioned max guaranteed IMC speed. For AMD it's like if you want to use faster memory then good luck.