Questions on RAM

[Dave Pastern]

Hi guys,

 

2 caveats.  

 

1.  I know nothing about overclocking.

 

2.  I know nothing about overclocking RAM.

 

Despite building my own PCs since '97, I never experimented with any form of overclocking.  

 

I am now getting the parts together to build a Ryzen 9 3900x system (will be using a Gigabye Aorus Master x570 motherboard).  I had settled on and ordered Corsair RAM from Amazon US - CMK64GX4M2D3000C16 - 2 x 32GB modules.  The system will be starting with 64GB RAM and will be upgraded to 128GB down the track as funds become available.  PC will run Kubuntu GNU/Linux with the sole reasoning to being to run PixInsight (a very specialised piece of software designed to process Astronomy images).  Now onto my questions...

 

1.  I believe the base clock speed for the 3900x CPU is 3600mhz and RAM that is slower than this clock speed will slow the CPU's performance?  Is this correct?  If so, by how much (percent) will I lose out?  

 

2.  How far could I push (overclock the 3000 sticks)?  Stability is of the utmost importance so as to avoid crashes when processing large .fits files in PixInsight.  Note: PixInsight is a beast and will saturate all cores/threads, use all of the RAM and is happy to exploit NVME PCIe gen 4 m2 SSDs as disk caches.  

 

3.  Some research tonight has led me to the term "B-die".  Reading up on it, it seems to refer to premium Samsung modules.  I checked this site (https://benzhaomin.github.io/bdiefinder/), and my RAM isn't B-die, so apparently doesn't lend that well to overclocking.  It seems that no manufacturer makes and B-die RAM in the size that I want (32GB module).  How much will this impact on the ability to potentially overclock the RAM that I bought?  

 

Am I better off returning the RAM (if Amazon will even accept a return on it) and going for 3600mhz RAM (Corsair LPX), or can I boost this 3000mhz RAM to 3600 or close enough so as to minimise any potential performance loss?

 

On a final point - if it is seemingly possible to boost the 3000mhz RAM, is anyone able to hold my hand and assist me with the RAM settings etc in detail? 

 

edit: this is Gigabyte's QVL:

 

https://download.gigabyte.com/FileList/Memory/mb_memory_x570-aorus-master_v1.1.pdf

 

I've heard of XMP but have no idea how to use it, etc.  I've simply never touched any RAM settings before, just leaving things at stock settings.

 

Hoping someone can answer my questions.

 

Cheers,

 

Dave

 

[AndreiArgeanu]

10 minutes ago, Dave Pastern said:

1.  I believe the base clock speed for the 3900x CPU is 3600mhz and RAM that is slower than this clock speed will slow the CPU's performance?  Is this correct?  If so, by how much (percent) will I lose out?  

CPU speed and ram speed have no connection of any kind so you should be fine. Generally speaking if you pick memory below 3200mhz you're losing quite a bit of performance, anything above 3600mhz, are only small performance improvements.

 

10 minutes ago, Dave Pastern said:

2.  How far could I push (overclock the 3000 sticks)?  Stability is of the utmost importance so as to avoid crashes when processing large .fits files in PixInsight.  Note: PixInsight is a beast and will saturate all cores/threads, use all of the RAM and is happy to exploit NVME PCIe gen 4 m2 SSDs as disk caches.  

It depends on a lot of factors on how far you can push ram, some people were able to push memory past 5000mhz, some can't push over their rated clock speed. Though you may be able to get to 3200, maybe a bit higher.

10 minutes ago, Dave Pastern said:

3.  Some research tonight has led me to the term "B-die".  Reading up on it, it seems to refer to premium Samsung modules.  I checked this site (https://benzhaomin.github.io/bdiefinder/), and my RAM isn't B-die, so apparently doesn't lend that well to overclocking.  It seems that no manufacturer makes and B-die RAM in the size that I want (32GB module).  How much will this impact on the ability to potentially overclock the RAM that I bought?  

You probably won't be able to push the ram very hard, only a few hundred mhz. Though again, anything over 3600mhz bring minimal improvements to performance.

10 minutes ago, Dave Pastern said:

Am I better off returning the RAM (if Amazon will even accept a return on it) and going for 3600mhz RAM (Corsair LPX), or can I boost this 3000mhz RAM to 3600 or close enough so as to minimise any potential performance loss?

You could see how well the ram overclocks and if it doesn't work out than if you really want to you can return it, and get higher frequency models. Just don't mention anything about overclocking when returning the memory. Again, with the memory overclocking you'll have to find out yourself when you get the memory modules. Just don't over-volt the ram too much.

[Stahlmann]

There is a lot going into RAM overclocking. And as someone who doesn't know about it i'd just recommend to return the 3000MHz kit and just buy a 3600MHz kit, as this is the performance sweet-spot for Ryzen CPUs.

 

But in any case, XMP is a very important setting. Without enabling the XMP in your BIOS the RAM sticks will run at their base frequency, which is 2133 or 2400MHz for DDR4 modules. Even if you buy a 3000MHz kit you still have to enable XMP to get the advertised speeds.

On AMD it can also be called "DOCP" in your BIOS.

[AndreiArgeanu]

11 minutes ago, Dave Pastern said:

1.  I believe the base clock speed for the 3900x CPU is 3600mhz and RAM that is slower than this clock speed will slow the CPU's performance?  Is this correct?  If so, by how much (percent) will I lose out?  

Another thing that I forgot to mention, while the clock speeds have no effect on the memory performance, the infinity fabric clock does (infinity fabric is only on ryzen to my knowledge). For best performance, from what I know, the infinity fabric should be clocked at half the advertised memory speed. So if your ram is clocked at 3600mhz, the infinity fabric should be overclocked to 1800mhz for best results. However I don't know a lot about the infinity fabric, so you might want to do a bit of research. There's also a useful video that you can watch about, ryzen, ram speeds and the infinity fabric below.

 

[Haro]

1. base clock for zen 2's imc is 3200 and anything over that is technically not guaranteed but 3600  and 1800 FCLK is generally easy to achieve with most zen 2 chips.

10 hours ago, Dave Pastern said:

and RAM that is slower than this clock speed will slow the CPU's performance?

anything over 3800 for zen 2 generally doesn't bring a big performance improvements as for anything slower, performance hit for anything below 3600, depends on the workload but it's over all nothing huge.

 

2. We don't know, depends on how good the board's topology is, how good the IC's are in that kit and how far they can be pushed and the imc's capabilities, every kit has different capabilities, only way to know how far you can go and at what timings and frequency is to try.

 

3. B die is a type of IC that is known for tight timings  and good overclocking headroom, something like 3200 cl14 or a 3600 cl16-16-16 are usually b die to give some examples.

10 hours ago, Dave Pastern said:

edit: this is Gigabyte's QVL:

Don't worry about QVL's for the most part.

 

10 hours ago, Dave Pastern said:

(will be using a Gigabye Aorus Master x570 motherboard

do you already have this board? it's an amazing board, it uses an XDPE132G5C and 12 sic639's, but is over kill for a 3900x and you don't need have to get such a high end board.

but if you're limited to it  and/or you set on it, it's a good board.

Edited September 10, 2020 by TofuHaroto
Some typos.

[Dave Pastern]

37 minutes ago, AndreiArgeanu said:

Generally speaking if you pick memory below 3200mhz you're losing quite a bit of performance

how much is "quite a bit" though?

37 minutes ago, AndreiArgeanu said:

You probably won't be able to push the ram very hard, only a few hundred mhz

OK, so perhaps to 3200mhz if I'm lucky...

37 minutes ago, Stahlmann98 said:

i'd just recommend to return the 3000MHz kit and just buy a 3600MHz kit, as this is the performance sweet-spot for Ryzen CPUs.

Yes, that is what I'm thinking of doing.  I actually meant to buy 3600mhz RAM, but was copying/pasting RAM model numbers from Gigabyte's QVL PDF and sometimes Windows doesn't obey ^c very well (i.e. not at all) and I copied the wrong model number into Amazon and didn't read things properly and clicked buy...I've had a real bad time with Amazon the past few months, but this was my fault.

37 minutes ago, Stahlmann98 said:

RAM sticks will run at their base frequency, which is 2133 or 2400MHz for DDR4 modules

In this instance, it's 2133mhz, at least according to Gigabyte's QVL PDF.

37 minutes ago, Stahlmann98 said:

On AMD it can also be called "DOCP" in your BIOS.

Thanks, will keep an eye out for it.  The last part arrived today (motherboard, yay!), but I'm still waiting on a few accessories to arrive for the build.  Will go through the BiOS once I start setting things up.

32 minutes ago, AndreiArgeanu said:

There's also a useful video that you can watch about, ryzen, ram speeds and the infinity fabric below.

Watching it now, thanks!

22 minutes ago, TofuHaroto said:

1800 FCLK is generally easy to achieve with most zen 2 chips.

I had to Google what FCLK is (infinity clock, right?).

22 minutes ago, TofuHaroto said:

how good the IC's are in that kit

I believe it's 1.2V, base speed 2133mhz, timings are 16-20-20-38 and the IC is Micron...make of that what you will.  

22 minutes ago, TofuHaroto said:

Don't worry about QVL's for the most part.

I've always used QVLs - rather not get into a fight between the RAM and motherboard manufacturers over who's to blame!

23 minutes ago, TofuHaroto said:

but is over kill for a 3900x and you don't need have to get such a high end board.

I read the 3900x benefits from the x570 chipset.  Plus, I wanted NVME PCIe gen 4 support.  That was critical for me (will be using a Seagate FireCuda M520 500GB gen 4 SSD and 2 x Samsung evo plus 256GB gen 3's for disk cache drives).  Yes, I know the 3rd m2 will disable 2 SATA ports, that's not an issue.  PixInsight can make use of disk cache (much like Photoshop's scratch disk).  

 

I think it will be easier to simply return the RAM that I purchased and shop for 3600mhz RAM (Corsair LPX).  

[Haro]

10 hours ago, Dave Pastern said:

(infinity clock, right?).

basically yea the frequency of the interconnect.

10 hours ago, Dave Pastern said:

rather not get into a fight between the RAM and motherboard manufacturers over who's to blame!

for the most part it doesn't matter.

10 hours ago, Dave Pastern said:

read the 3900x benefits from the x570 chipset.  Plus, I wanted NVME PCIe gen 4 support. 

ah no, i was talking about the specific board lol.

but if you're set on it yea it's a pretty good board.

10 hours ago, Dave Pastern said:

it's 2133mhz, at least according to Gigabyte's QVL PDF.

the ram will load the base spd profile on it, which is usually around 2133/2400, to load the spd profile to run them at their advertised frequency, you will need to enable xmp/docp.

[Dave Pastern]

20 hours ago, TofuHaroto said:

for the most part it doesn't matter.

Well, if I have stability issues, I have more of a leg to stand on with Gigabyte should memtest show no issues with the RAM modules.  Just covering my bases.  

20 hours ago, TofuHaroto said:

but if you're set on it yea it's a pretty good board

Yup, only the best!  I want this PC to last at least 5 years, and from my experience, investing in better quality parts generally improves that chance. Plus, it's real perty lol!

20 hours ago, TofuHaroto said:

the ram will load the base spd profile on it, which is usually around 2133/2400, to load the spd profile to run them at their advertised frequency, you will need to enable xmp/docp.

I will check that out when I've built the new PC.  Still waiting on a few parts to arrive.

 

I will try and see if Amazon will agree to a return and get 3600mhz RAM.  If they don't, then I'll see what my local Fair Trading says on the matter.  Does OC technically render the warranty invalid?  Can RAM vendors tell if memory has been OC?

[Haro]

20 minutes ago, Dave Pastern said:

Can RAM vendors tell if memory has been OC?

Loading the xmp profile doesn't void the warranty.

[Dave Pastern]

23 hours ago, TofuHaroto said:

Loading the xmp profile doesn't void the warranty.

I thought it was worth asking!

[Dave Pastern]

On 9/11/2020 at 4:39 PM, TofuHaroto said:

Loading the xmp profile doesn't void the warranty.

Actually, for some pre-built systems manufacturers, it does...NZXT up until very recently had a policy that XMP voided warranty...due to public pressure and talk of false advertisement (selling a system with 3400mhz RAM that only runs at 2133!), they reversed their decision and now XMP is covered and doesn't void warranty...

 

https://blog.nzxt.com/updating-our-warranty-an-xmp-story/

[Haro]

10 hours ago, Dave Pastern said:

they reversed their decision and now XMP is covered and doesn't void warranty

That would be dumb, but you're not going to get a prebuilt either way right? 

[Dave Pastern]

11 hours ago, TofuHaroto said:

That would be dumb, but you're not going to get a prebuilt either way right? 

No.  It was more to prove that some places are indeed voiding warranty if XMP is used.  Very sad imho.