# DDR4-2133 Kit (4x8GB) or 4 modules with 8GB ? [solved]

## Keruskerfuerst

I want to buy 32GB RAM DDR4-2133.

Is it better to buy a kit of 32GB (4x8GB)

or 

4 modules from the same manufactorer?Last edited by Keruskerfuerst on Sun Feb 21, 2016 10:06 am; edited 1 time in total

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## snkmoorthy

If you buy as a kit, there is this assumption that the modules were matched by some process and there is some guarantee to them giving no compatibility issues. On the other hand, if you buy all modules from the same seller, you are most likely to end up with modules that came off the same batch with similar performance rating. If there is no price difference get the matched pairs.

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## krinn

look at your m/b rams list of valid vendor and combination of ram to get upto 32gb, that's either given in the m/b manual, or at the m/b maker website.

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## Keruskerfuerst

I have bought a 4x8GB Kit DDR4-2133 RAM from Kingston: Kingston HyperX Savage with XMP profile.

Works absolutly stable in a Asus X99-Deluxe mainboard and a Intel Core I7-5820K CPU.

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## NeddySeagoon

Keruskerfuerst,

Have you actually used all 32G?

Maybe you fitted 32G but only use 1G  :)

How do you know its all stable?

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## msst

 *Quote:*   

> Have you actually used all 32G?
> 
> Maybe you fitted 32G but only use 1G  

 

That is a very good remark. I also had 32 GB fitted for more than half a year before I found out that one of the modules on the upper 16 GB was broken. No problems in normal use at all. And too late for warranty. 8-(

However once I ran a big backup where I copied many large files into a large container. Bang, crash of the system.  Repeatedly. Apparently the filesystem cache was now using for once >16 GB.

A couple of hours later a memory check run (which takes very long to complete on 32 GB) revealed the problem. Since then I have not replaced the faulty module but run 16 GB. The difference 16 vs 32 GB is not noticeable. You'd need to do some very special computation tasks or use it on a massive server to see the difference.

Conclusions:

1) For the start 16GB are likely enough unless you have some very specials reasons to believe otherwise.

2) Run a full 24h memory checks on the whole ram after installation

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## depontius

 *NeddySeagoon wrote:*   

> Keruskerfuerst,
> 
> Have you actually used all 32G?
> 
> Maybe you fitted 32G but only use 1G  
> ...

 

After installing and verifying basic operation, boot to memtest86+ and let it run at least overnight, preferably for a day or two, or gather at least two runs through the whole address space.  Shy of a real tester, this is about as good as you're going to get.

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## Keruskerfuerst

I work with my computer from 6:00 to 18:00.

No crashes all all...  :Idea: 

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## Buffoon

 *NeddySeagoon wrote:*   

> Keruskerfuerst,
> 
> Have you actually used all 32G?
> 
> Maybe you fitted 32G but only use 1G  
> ...

 

I see it all the time, 32 or 16 GB installed, 1 GB in use. Many users seem to think adding more RAM is a sure ticket to performance increase.

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## Syl20

<troll>Windows users ?</troll>

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## saellaven

 *Buffoon wrote:*   

>  *NeddySeagoon wrote:*   Keruskerfuerst,
> 
> Have you actually used all 32G?
> 
> Maybe you fitted 32G but only use 1G  
> ...

 

both libreoffice and palemoon got pulled in during my update last night...  both emerged simultaneously with --jobs=9 --load-average=9.0

     Thu Feb 25 23:56:08 2016 >>> www-client/palemoon-26.1.1

       merge time: 1 hour and 9 seconds.

     Fri Feb 26 00:04:21 2016 >>> app-office/libreoffice-5.1.0.3

       merge time: 1 hour, 46 minutes and 32 seconds.

It never went to swap with 16 GB (at $70, it didn't break the bank). Sometimes, it's nice to have all that extra RAM. Granted, for most people, it's probably overkill, but for Gentoo users, it can be handy. Same system at idle is eating up 2.6 GB (though palemoon is eating up most of that).

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## Keruskerfuerst

I have a X99 mainboard.

I bought 4 double sided DDR4 modules.

These modules have 8 GB each.

Before I had 4 and then 8 modules DDR4-2133 RAM from cruical.

4 of 8 modules where defective and had no XMP profile.

I send them back to the distributor.

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## Keruskerfuerst

This RAM kit is not listed in the list of recommended RAM modules for that mainboard.

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## depontius

Any comment on buying four as a kit vs buying two, then adding two same-spec, same-brand, same-model later?

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## Keruskerfuerst

I have bought a kit of 4 x 8GB RAM modules.

I don´t know, if the modules are matched.

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## Cyker

While matched pairs is nice, it's far from necessary. As long as all the modules support a common frequency then you can use any ones you like; My old server had 4 different DIMMs from 3 different manufacturers in it as they were all scrounged and it was running 24/7 just fine for many years!

(I did get through 6 other scrounged modules before that; Some of a lower capacity and some which were faulty, but such is the life of a cannibal  :Razz: )

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## Roman_Gruber

 *Buffoon wrote:*   

>  *NeddySeagoon wrote:*   Keruskerfuerst,
> 
> Have you actually used all 32G?
> 
> Maybe you fitted 32G but only use 1G  
> ...

 

it depends on how you use the extra ram. keywords building software in tmpfs; storing temp files and download folder in ram ... less write cycles on disc ... 

And if the new types are faster as the old ones. Mine have had a slight increase in performance regarding building packages

Thanks for hte hint with memtest. on the ohter hand i also bought kingston and they have a good policy of warranty. 

Ram i a very costly performance increase tweak but it increases slightly.

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## Roman_Gruber

 *depontius wrote:*   

> Any comment on buying four as a kit vs buying two, then adding two same-spec, same-brand, same-model later?

 

As said it depends on the mainboard. I would not go for single ram packages. 

buy ether 2 or 4 kits of ram. afaik ram controller these days work with 2 ram dimms at a time (so those should fit). as mainboards and chipsets are different, i will not give any recommendation. 

I am happy i sold these no name hynix ram which were preinstalled. 

afaik buying 2 kit and adding later a 2 kit with similar timings from the same manufacturer or a decent manufactuerer should work. again check how the chipset adress those rams, what forums says about your mainboard and such. 

And i agree with neddy, it could be that you only use a small area of your rams. 

memtest is a way to test ram, but there is still possible faults there which are not obvious, or memtest does not cover at all.

whats the magic behind those kits, its hard to say, they claim they fit better together, but if its true or not, who knows the magic behind it?

Those hynix ram i had claimed to run at the same speed as those kingston overclocker ram which i have now in my notebook. but how comes the compile times went down for libreoffice ? do not trust noname brands like hynix ...

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