AMD Ryzen has issues with high frequency RAM! - Fix will come in 1-2 months

[Colonel_Gerdauf]

7 minutes ago, Starelementpoke said:

Eh. Don't think many people get ram much faster than 2400mhz, even with DDR4 that often anyway.

 

Like @Enderman said, 2400MHz is considered the bar minimum for a Z-series or X-series motherboard. The only speed slower than that is 2133MHz (the JEDEC standard), which is not only worse in clock speed, but the timings leaves something to be desired. The specifications for regular DDR4 is 2133-CL15, whereas the most common XMP timing found on retail DDR4 sticks is CL14.

 

@MageTank can correct me here if he so wishes, but from what I know, 3200MHz is the sweet spot before the price differences become astronomical. Meanwhile, 2400MHz is the best you can get without altering the IMC values.

[Valentyn]

40 minutes ago, Pohernori said:

inb4 "ram speed doesn't matter" 

 

heh

Well not when timing come into play 2666Mhz at CL13 vs 3000Mhz at CL16

[FratStar]

As a person who preordered I'm struggling to find the fucks I'm supposed to give. I'm running 2x16 2800 ram I think so I don't even care that much.

[Okjoek]

I don't think that's really a problem for most people is it? I mean Unless I was using an older APU I don't think I would ever bother to get RAM higher than 2400mhz.

[MageTank]

15 minutes ago, Colonel_Gerdauf said:

 

Like @Enderman said, 2400MHz is considered the bar minimum for a Z-series or X-series motherboard. The only speed slower than that is 2133MHz (the JEDEC standard), which is not only worse in clock speed, but the timings leaves something to be desired. The specifications for regular DDR4 is 2133-CL15, whereas the most common XMP timing found on retail DDR4 sticks is CL14.

 

@MageTank can correct me here if he so wishes, but from what I know, 3200MHz is the sweet spot before the price differences become astronomical. Meanwhile, 2400MHz is the best you can get without altering the IMC values.

I appreciate you calling me in on this, this is very interesting indeed. As for the question of "how much ram speed do I need" or "at what point do we hit diminishing returns", it depends entirely on your system configuration and the application in question. For the most part, using a GTX 1070 and a 6700k, I found tight 2800mhz to be the best bang for the buck. They are relatively cheap for that price, and going much higher didn't really yield that much additional performance, except in a few applications. With a more powerful GPU, you can see scaling beyond 2800mhz (even up to 3600mhz in some applications).

 

Since 2800mhz kits are not as common as 3000 or 3200, either of those two will be better options.

 

As for why this is happening, I can explain what is going on. ASUS already touched on the 2DPC issue (you have tertiary timings specifically devoted to how many dimms you have per channel) and these timings must be adjusted when you populate 2 dimms within a specific channel. The reason high-frequency ram is an issue when populating both dimms of a channel, is because it's putting insane stress on the IMC. As we overclock for higher frequency, we must make up for it with loose tertiary timings so that the IMC doesn't freak out. The other alternative option is more VCCIO/SA volts, but that's not an ideal solution in terms of longevity. There are other workarounds as well, but it will depend entirely on whether or not we get access to specific tertiary timings to relieve stress off the IMC.

 

I'd love to give it a shot, and I likely will once Ryzen launches. Either way, I highly recommend people run 1DPC anyways, due to how much easier it is to overclock. Part of the reason why the Asrock Z170m OCF board does so well, is the fact that it's only 2 DIMMS (1DPC) and the trace topology is wired very close to the CPU. Ignoring the trace topology, 1DPC allows you to completely ignore the DPC subset timings. This means less stress on the IMC, meaning more headroom for higher frequencies/tighter timings. Besides, you can get 2x16GB kits for relatively the same price as 4x8GB. The tradeoff being: 16GB DIMMS are harder to hit higher frequencies with, but i'd advise people not to worry too much about clock speed, and focus more on tightening the timings. There is a reason my 3600 C14 manual overclock beats any DDR4 4000+ XMP on the market in terms of raw bandwidth and latency.

[alamox]

Ryzen doesn't have the issue, it's the Asus motherboards that got the issue, that they will patch later on.

beside ppl need to understand that Ryzen is a completly new architecture, it's not an old one that is being revised and tweeked for few generation, so at launch you are bound to run to some issues, motherboards will mainly focus on stability, then we will see mobos focusing on overclocking.

[MageTank]

Just now, alamox said:

Ryzen doesn't have the issue, it's the Asus motherboards that got the issue, that they will patch later on.

beside ppl need to understand that Ryzen is a completly new architecture, it's not an old one that is being revised and tweeked for few generation, so at launch you are bound to run to some issues, motherboards will mainly focus on stability, then we will see mobos focusing on overclocking.

How do you know it's limited only to ASUS? ASUS themselves said it's on AMD's end, and is waiting for a microcode update to fix it. It wouldn't surprise me either, as AMD has always had issues with memory support in the past, and their overclocking options have always been limited in the memory department as well. 

[Valentyn]

11 minutes ago, MageTank said:

i'd advise people not to worry too much about core clock, and focus more on tightening the timings. There is a reason my 3600 C14 manual overclock beats any DDR4 4000+ XMP on the market in terms of raw bandwidth and latency.

 

Something people always forget; and someone in this thread even goes so far that it's unacceptable to have a build without all the slots filled. That makes little sense really; as for the longest time the less DIMMS meant you could get tighter timing and better clocks overall with less strain on the IMC.

I was a silly bastard when X99 launched though. I was extremely impatient and just snapped up the only RAM left in stock as I desperately needed a workstation. Ended up paying over £550 for 32GB of 2400Mhz CL14 sticks.

Not the worst at all; but there were better sticks out there for cheaper; even now. People shouldn't get hung up on 3200Mhz Plus alone, there's more to RAM than just frequency and filling all the slots right away.

 

Even so, I can see this being an issue for some people; but they'll likely be a minority. Not many gamers; especially budget oriented ones needs 32-64GB of High performance memory.
I just hope the Microcode update via the BIOS comes out soon though; AMD doesn't need another launch marred by something that can be fixed via an update.

[Mr.Meerkat]

18 minutes ago, huilun02 said:

But of course anyone making a Ryzen build this late would demand no less than 32GB of memory, thus the necessity to use all 4 slots.

 

Who makes new builds with only two slots occupied anyway? Its unacceptable even if it allows 3200+Mhz. This alone justifies the extra $500+ for the i7-6900K. 

I'm sorry, Wut? 32GB across 4 slots, are you mad? Why would you not go dual 16GB sticks?  

[MorganO]

54 minutes ago, Mr.Meerkat said:

Kek  

https://www.ocaholic.ch/modules/smartsection/item.php?itemid=4003&page=7

 

17% improvement going from either 2133/2400MHz RAM to 3000MHz RAM with an OCed i5 6600K...

Am I kinda cherry picking? Yep but it can make a considerable difference...(hehe, 8320 wrecking the skylake i5...)

 

Kinda true and not true where it doesn't really in gaming but in other tasks, possibly...(such as Winrar) 

eh i did ask if it was true soooo

[MorganO]

55 minutes ago, MeDownYou said:

OH NO! you mean i have to go into bios and set ram to lower speeds for a month or just not set XMP profile for a month, how infuriating that they are probably working on getting a fix for this before launch and early adopters should expect flawlessness 

 

/s

i said what i said sarcasticaly although i did miss the /s 

 

such first world problems we have today

[Zi6iX]

Glad i only bought 2 sticks. Like any sane person would do

[That Norwegian Guy]

1 hour ago, Colonel_Gerdauf said:

 

Like @Enderman said, 2400MHz is considered the bar minimum for a Z-series or X-series motherboard. The only speed slower than that is 2133MHz (the JEDEC standard), which is not only worse in clock speed, but the timings leaves something to be desired

2133Mhz RAM doesn't have to be JEDEC compliant though, there are CL10 and CL11 DIMMs out there.

 

I'd choose 2133Mhz at CAS 10 over 2400 and CAS 15 in a heartbeat.

 

Though it's not a necessary choice, as there are 2400Mhz CL11 options.

[Simon771]

Well that's not that bad. It could be worse, and I hope no other problems will come to surface with Ryzen.

So for all those who will be using higher than 2400MHz, just set in BIOS and downclock RAM. Problem solved?

[Taja]

People here actually care about that? Wtf (well, ofc you can care, but this is hardly very relevant)

[SpaceGhostC2C]

1 hour ago, Okjoek said:

I don't think that's really a problem for most people is it? I mean Unless I was using an older APU I don't think I would ever bother to get RAM higher than 2400mhz.

Provided we are talking about "normal" CL and timings, that means we shouldn't care about DDR4 either, as something like 24000MHz CL15 would be slower than reasonably fast DDR3 kits.

(At least that was the answer I got in this forum when I asked if there is any reason why DDR4 should be faster than DDR3 at the same frequencies and timing, and whether there was any reason why I should prefer DDR4 2133 CL15 to, say, DDR3 2133 CL10 or 1866 CL9).

[LAwLz]

Why am I not surprised that everyone is really quick with jumping in to defend AMD and even going as far as to blame Asus?

As soon as I opened this thread I knew it would be filled with comments like: "This is not AMD's fault it's the motherboard manufacturers!", "You don't need fast RAM anyway!" and "Intel has issues too!".

 

It's like some people need to defend AMD at least two times a day or else they die from a lack of AMD cock in their bums.

 

 

Also, lol at people who don't understand what CL is. Higher number does not necessarily mean higher latency if the frequency isn't the same. CL16 can be lower latency than CL14 for example.

[Drak3]

1 hour ago, Colonel_Gerdauf said:

The only speed slower than that is 2133MHz (the JEDEC standard), which is not only worse in clock speed, but the timings leaves something to be desired. The specifications for regular DDR4 is 2133-CL15, whereas the most common XMP timing found on retail DDR4 sticks is CL14.

JEDEC's standard has DDR4's starting speed at 1600MHz, and provides spec for 1866MHz DDR4 as well. Not that it really matters, 2133MHz is the perceived minimum that manufacturers want to go with for consumer RAM. Moving to Xeon and ECC memory, seeing 1600/1866MHz DDR4 becomes more common.

[SpaceGhostC2C]

8 minutes ago, LAwLz said:

Why am I not surprised that everyone is really quick with jumping in to defend AMD and even going as far as to blame Asus?

As soon as I opened this thread I knew it would be filled with comments like: "This is not AMD's fault it's the motherboard manufacturers!"

I didn't read that specific one here, although I may have skipped something  

[MageTank]

10 minutes ago, LAwLz said:

Why am I not surprised that everyone is really quick with jumping in to defend AMD and even going as far as to blame Asus?

As soon as I opened this thread I knew it would be filled with comments like: "This is not AMD's fault it's the motherboard manufacturers!", "You don't need fast RAM anyway!" and "Intel has issues too!".

 

It's like some people need to defend AMD at least two times a day or else they die from a lack of AMD cock in their bums.

 

 

Also, lol at people who don't understand what CL is. Higher number does not necessarily mean higher latency if the frequency isn't the same. CL16 can be lower latency than CL14 for example.

I can actually demonstrate this if need be. Plenty of people give primary timings far too much credit. Tertiary timings is where the real bandwidth comes from, and with more bandwidth, comes lower latency (assuming you are not loosening primaries to tighten tertiaries). The biggest impact I've personally seen with overall latency, is RTL/IO-L offsets. The hint is even in the name (Round Trip Latency). People completely neglect this important metric, mostly because it's never advertised anywhere when you buy ram. 

 

As for blaming ASUS, that's just silly. Ask any memory overclocker. ASUS has the best memory training out of any motherboard manufacturer ever. Sure, ASRock's Z170m OCF has superior trace topology compared to ASUS's 4DIMM boards, but that all goes away once you factor in the ROG Impact. This is all without even mentioning ROG Scramble, which will allow even unstable memory to post just fine. If they couldn't get 3000-3200 working with Scramble, something is seriously wrong on the IMC side of things. Now, I am certain this can be solved if they'd give access to the finer grain control of the IMC (ASUS seems to think so as well, according to their statement in the OP), it's still to be seen how well this IMC will even do. If anyone recalls my posts about Zen for the last few months, it's IMC has always been my number one concern. Now you all understand exactly why it was a concern for me. 

[dexT]

37 minutes ago, Zi6iX said:

Glad i only bought 2 sticks. Like any sane person would do

It's more of a problem for people on X99 with quad channel kits that would move it over.

[Starelementpoke]

2 hours ago, Enderman said:

2400 is like, minimum for ddr4....

Almost all DDR4 is 2400 and above.

Thought the minimum was 2133?

[JamieOlive]

Look I have a few set of either DDR-3 OR DDR-4 RAM, and from 1866Mhz to 3000Mhz there is a difference, but between 2400Mhz to 3000Mhz I don't see differneces above  a couple seconds, and even if there are scenarios that you find more tangible differences, 2 sticks will do just find.

 

I personally will get 16Gb of DDR-4 on my Ryzen 7 1700 when I order it(I haven't preorder and dismmised the other 2), cause it is more than enough for my home PC, "I cup at around 10-11Gb of use", and truth be told even my Pro x99 PCs at work runiing at 32Gb of DDR-3  @1866Mhz and 4960X CPUs, RAM utilization is no more than half 90% of the time, so 16Gb is more than enough for Consumer and Proffesionals.

 

Personally I think the glitch will take less than 2 months to fix, cause it is a known error for more than 1 Generation of either AMD OR Intel, and they know how to fix it.

[Drak3]

3 minutes ago, Starelementpoke said:

Thought the minimum was 2133?

1600, actually. 2133MHz is just the lowest most manufacturers go with when making consumer RAM.

[Enderman]

4 minutes ago, Starelementpoke said:

Thought the minimum was 2133?

I said almost