PC Processors

[radomirpolach]

For the love of god could anybody tell me the maximum supported RAM capacity? I have seen 64GB, I have seen 128GB. It works in BIOS with 128GB, but I have problems running OS with it.

Would it be possible for AMD actually put this information on the web into what it calls "Full Specification":

https://www.amd.com/en/product/10246

[elstaci]

The Maximum amount of RAM is determined by your Motherboard and not the processor. Generally most Consumer Motherboards supports up 128 GB of RAM Memory.

You need to look at your Motherboard's SPECS to see how much RAM it will support.

Plus the Motherboard has a RAM MEMORY QVL List that lists all RAM that are compatible AND also which ones supports 128GB of RAM.

Laptop motherboards supports less RAM than Desktop Motherboards.

[radomirpolach]

Good joke.

If I put Ryzen 5 2600 into my motherboard that supports 128GB RAM, does it starts magically working?

No. It won't because Ryzen 5 2600 supports only 64GB RAM.

[elstaci]

@radomirpolach 

This is what I also wrote in my previous reply "Plus the Motherboard has a RAM MEMORY QVL List that lists all RAM that are compatible AND also which ones supports 128GB of RAM"

The Motherboard in its QVL List will show you if a processor supports 128GBs or not.

If the QVL List shows a maximum of 64GB RAM Part numbers then that tells you that is the maximum it will support but the motherboard can still support 128GB with other processors installed.

You are correct that that processor 2600 only supports 64GBs and when you go to 500 series Motherboard its QVL List for the 2000 series processor will show you that it supports only 64GBs and not the full 128GB of the motherboard for other processors.

AS AN EXAMPLE ONLY:

This ASRock Motherboard supports 128GB of RAM and supports the Ryzen 5 PRO 4650g processor: https://www.asrock.com/mb/AMD/X570%20Taichi%20Razer%20Edition/Specification.asp#Specification

The QVL List for the Renoir for the ASRock Motherboard which is the Ryzen 5 PRO 4650g it shows several 32GB RAM compatible in 4 DIMM Slots which comes out to 128GB of Maximum RAM:

So you need to look at the Motherboard's RAM Memory Specs and the QVL List for RAM for your processor to determine if it support 128GB of RAM or not.

Plus you never mentioned anything about using a  Ryzen 2600 processor.

[elstaci]

At WikiChip it mentions that the Ryzen 5 2600 Maximum Memory it supports is 128GB: https://en.wikichip.org/wiki/amd/ryzen_5/2600

So it is possible for the 2600 to support 128GB of RAM.

BUT The Ryzen 5 2600X only supports a Maximum of 64GBs: https://en.wikichip.org/wiki/amd/ryzen_5/2600x

[radomirpolach]

The same RAM modules worked with Ryzen 5 3600 which is Renoir as well. So this doesn't really give me much. This is why I am asking about what the CPU really supports.  I tested two different AMD Ryzen™ 5 PRO 4650G and they both have the same behaviour, unstable with 128GB RAM. Ryzen 5 3600 worked.

---

@elstaci wrote:

You are correct that that processor 2600 only supports 64GBs and when you go to 500 series Motherboard its QVL List for the 2000 series processor will show you that it supports only 64GBs and not the full 128GB of the motherboard for other processors.

This isn't true.  Looking here:

https://www.asrock.com/mb/AMD/X570%20Taichi%20Razer%20Edition/Specification.asp#MemoryPR

Pinnacle Ridge shows 32GB 2/4 modules combinations as well. So this is complete mystification. 

[elstaci]

why don't you just open a AMD Support ticket and ask them directly about the Maximum RAM that the 4650g support: https://www.amd.com/en/support/contact-email-form

[elstaci]

Every Motherboard has a different QVL List for RAM MEMORY for the same processors.

Like, again. I mentioned in my previous reply it all depends on your Motherboard Specs.

[PlzkyChobot]

Ryzen 5 3600 is not Renoir though, it differs from Ryzen 5 PRO 4650G, since it is different chip. R5 3600 has one 7nm CPU chiplet and central IO die, while 4650G is monolithic chip.

I would recommend getting latest BIOS, check the QVL list for your motherboard.

You might want to get a server style board, like ASRock Rack ones, these do support ECC and large DIMMs, plus they have IPMI onboard.

Also, if you are experiencing stability issues, try pushing a little bit voltage into VSOC, about 100 mV should be fine. I do it on AM4 systems that have issues with memory overclocking OR when all four DIMM slots are used. You could try increasing voltage for the RAM as well, that helps stability at higher clocks as well.

Remember that dual-rank and quad-rank is more intensive for the memory controller.