Why does Ryzen not like 4 DIMMs?

Alan0387 · 5 Jul 2020 at 11:47

So having just built my pc before lockdown, a Ryzen 3200g based system with MSI Mortar Max B450, to get her up and running due to budget constraints at the time I installed 8gb (x2 4gb sticks) of Hyper X Fury 3200mhz Ram. Then for father's Day the kids got me another 8gb of the same memory. I chose it, to ensure the correct one! Bought from same vendor, same SKU etc.

After installing and setting everything up, I noticed although my full 16gb is shown, it runs at stock speeds of 2133, it refuses flat out to overclock to its rated xmp profile of 3200.

The original sticks I had running stable over 3400 on one of MSI 'try it' memory profiles.
To eliminate any issues I removed the new sticks, reset ram to previous oc profile, all good. Fit the new sticks in place, they ran stable at over 3400. But once 4 sticks go in together they stick at 2133, regardless of voltages in the controller or DIMMs. All available updates and patches are installed.

Subsequent research shows this is a common issue with Ryzen right back to first gen. So my question is, has anybody found a workaround to this or is it a choice of 16gb over 2 sticks at 3200 or 16gb over 4 sticks at 2133? I may be able to return the sticks from father's Day but since they have been opened and they are not technically faulty, I'm not so sure. As a pc that is mainly used for household work and mild gaming (my PS4 is being worked overtime in warzone currently) which benefits Ryzen more, speed or quantity?

Apologies for long post, just trying to give as much info as possible!

Thanks,
Alan

Tetras · 5 Jul 2020 at 13:48

Do you use the IGP for the gaming?

hyperseven · 5 Jul 2020 at 13:56

Isn't it down to the motherboard as well, on the topology it has implemented?

robfosters · 5 Jul 2020 at 16:24

hyperseven said:
Isn't it down to the motherboard as well, on the topology it has implemented?

Definitely, I have 4 sticks of 3200 running full speed with no problems at all

EsaT · 5 Jul 2020 at 17:27

Probably multiple reasons:

Despite of its model number 3200G is Zen+ based, whose memory controller is mediocre at best and 3200MHz is quite high speed for it even in good circumstances.
Then two DIMMs per channel is worser for signaling with common daisy chain memory slot wiring increasing demands for memory controller.
Also there's no quarantee those memories are with same DRAM chips and newer sticks might well be something that mediocre memory controller just doesn't handle well.
Only DIMMs with certainly known chips are Crucial Ballistix models with Micron rev.E and 3200MHz CL14 and 3600MHz CL16 with high bin Samsung B-die.
3200MHz CL16 can be anything.

By running new kit separately (in slots you had original kit) you could try bracketing, if it has chips memory controller won't run 3200MHz even alone, or if it's first two reasons.
Anyway something like 2933Mhz or 3000Mhz might be easily reachable max with four DIMMs.

robfosters said:
Definitely, I have 4 sticks of 3200 running full speed with no problems at all

You have Zen2 there with vastly improved memory controller.

pugheaven · 8 Jul 2020 at 10:17

Alan0387 said:
So having just built my pc before lockdown, a Ryzen 3200g based system with MSI Mortar Max B450, to get her up and running due to budget constraints at the time I installed 8gb (x2 4gb sticks) of Hyper X Fury 3200mhz Ram. Then for father's Day the kids got me another 8gb of the same memory. I chose it, to ensure the correct one! Bought from same vendor, same SKU etc.

After installing and setting everything up, I noticed although my full 16gb is shown, it runs at stock speeds of 2133, it refuses flat out to overclock to its rated xmp profile of 3200.

The original sticks I had running stable over 3400 on one of MSI 'try it' memory profiles.
To eliminate any issues I removed the new sticks, reset ram to previous oc profile, all good. Fit the new sticks in place, they ran stable at over 3400. But once 4 sticks go in together they stick at 2133, regardless of voltages in the controller or DIMMs. All available updates and patches are installed.

Subsequent research shows this is a common issue with Ryzen right back to first gen. So my question is, has anybody found a workaround to this or is it a choice of 16gb over 2 sticks at 3200 or 16gb over 4 sticks at 2133? I may be able to return the sticks from father's Day but since they have been opened and they are not technically faulty, I'm not so sure. As a pc that is mainly used for household work and mild gaming (my PS4 is being worked overtime in warzone currently) which benefits Ryzen more, speed or quantity?

Apologies for long post, just trying to give as much info as possible!

Thanks,
Alan

Use CPUZ mate and go into memory with all four stick in. Then go into the SPD tab if it has one and note what setting are available for each slot DIMM and note the XMP or however, what you might find is that XMP (or whatever it's called on AM platform can't remember now), that the two new ones are of a slightly different speed setting... it's worth a check as I've got 64GB of ram, 48 was bought from one vender and the other 16 from another and I find that the 48GB is missing the updated XMP profile and thus I have to manually set the timings, however they're both "in theory" the same spec.

Quartz · 8 Jul 2020 at 10:38

Alan0387 said:
After installing and setting everything up, I noticed although my full 16gb is shown, it runs at stock speeds of 2133, it refuses flat out to overclock to its rated xmp profile of 3200.

I've looked through the RAM compatibility list for HyperX and that board doesn't appear to support any 3200 MHz HyperX RAM in quad channel with a 3200G CPU.

Joxeon · 8 Jul 2020 at 18:35

Alan0387 said:
So my question is, has anybody found a workaround to this or is it a choice of 16gb over 2 sticks at 3200

This would be a work around.

EsaT said:
something like 2933Mhz or 3000Mhz might be easily reachable max with four DIMMs

The other option is to sell the 4x4gb and buy a 2x 8gb kit.

agw_01 · 8 Jul 2020 at 18:41

I run 96GB of Corsair Vengence LPX in a B450 board with a 2600 without any issues.

Granted I have to run the 3200MHz RAM at 2666 to get it stable, but that's to be expected with the IMC in Zen/Zen+. I wouldn't have expected much trouble running 16GB at 3200.

Alan0387 · 10 Jul 2020 at 15:09

Thanks everybody, apologies for my late response, I've had a nightmare week in work

I really appreciate all the advice and tips given above and I have some time set aside from wife/kids this weekend to try out suggestions above!

Quickly answering some questions;

Yes I do use the iGPU for gaming, but never was planned for long term, this build was always planned as a learning/upgrading experience and budget was large factor in initial building, which the Ryzen APU helped with.

I have cpuz installed as part of a pack of programs recommended from various YouTube channels for learning overclocking so I'll check that out too.

I forgot about the compatibility lists, I never thought to check them, d'oh :rolleyes:

I might run a few games/benchmarks with the 4 sticks at stock speed and see how it fares for now, I would like to put a Zen 2 in there with a decent GPU. I got sucked into the Ryzen NEEDS fast memory to work theory, but for my spec pc, quantity might make up for that shortfall in pace.

I've tested both sets of memory and each set will run over 3400mhz stable so it's just down to my board/CPU combo it seems

Tetras · 10 Jul 2020 at 15:22

If you use the IGP 2x4 at 3400 will be significantly faster than 2133, to the point that some games may be playable that are not otherwise. For desktop usage, 16GB will feel better, especially if you don't have a SSD. But, you should be able to get higher than 2133 stable.

Armageus · 10 Jul 2020 at 15:36

Alan0387 said:
I forgot about the compatibility lists, I never thought to check them, d'oh

I wouldn't put too much faith in them though - they're rarely updated after the fact, and even different BIOS version can affect compabitility.

Interestingly the MSI compatibility link above shows all the Kingston modules as being tested at 1.2V with most only achieving 2133mhz.
(Rather than the 1.35v required for 3000 or 3200)

https://www.kingston.com/dataSheets/HX432C16FB3K2_8.pdf

Avalon · 16 Jul 2020 at 01:42

agw_01 said:
I run 96GB of Corsair Vengence LPX in a B450 board with a 2600 without any issues.

Granted I have to run the 3200MHz RAM at 2666 to get it stable, but that's to be expected with the IMC in Zen/Zen+. I wouldn't have expected much trouble running 16GB at 3200.

Aren’t both the B450 and the Ryzen 2x00 series are officially limited to 64GB?

Joxeon · 16 Jul 2020 at 09:26

Avalon said:
Aren’t both the B450 and the Ryzen 2x00 series are officially limited to 64GB?

128gb according to the spec page on the tomahawk max.

https://www.msi.com/Motherboard/B450-TOMAHAWK-MAX/Specification

agw_01 · 16 Jul 2020 at 10:30

I think it was originally thought as being a limitation in the CPU's IMC but was later discovered to be motherboard dependent.

In the case of my Asus Strix B450-F, when I originally bought the board the spec sheet only listed it as supporting 64GB RAM max. It was only after I read more into it not being limited by the CPU I re-checked and the maximum RAM supported by the motherboard had been increased to 128GB. I've not flashed the BIOS since getting the board either.

Tetras · 16 Jul 2020 at 13:08

The 9th gen CPUs were similar if I recall, they were 64GB, but later it was clarified that they support 128GB.

LtMatt · 16 Jul 2020 at 21:32

Make sure you are on the latest BIOS for your board too as this may help you achieve a higher frequency. I would try and get 3000Mhz stable and see if you can work up from there slowly testing any frequency or timing changes slowly using memtest hci to validate stability.