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by nubinetwork 746 days ago
I'd love to replace my 2950x, but most desktop motherboards still don't support 128gb of memory.
8 comments

No, a lot support 128GB. Some support 192GB or even 256GB: https://skinflint.co.uk/?cat=mbam5&xf=317_X670E&asuch=&bpmin...
You can run 4x32 DDR5 on current gen AMD consumer platforms but don't expect speeds above 4400MHz in quad-channel regardless of what the module is rated for. I'd instead suggest dual channel 48GB DIMMs for 96GB at full speed.
4 DIMMs does not equal Quad-channel. I see in AMD's presentation Quad-channel is supported by chipsets, but I am not aware of a current AMD consumer/hedt chip with 4 memory channels.
Non-Pro Threadripper 7960X/7970X/7980X are Quad Channel. (The Threadripper Pro's are Octa-Channel)

But yeah, Desktop Ryzen's are all Dual Channel.

True, but the Threadripper requires the TRX50 platform, so I still don't understand what is operative about the statement that the X870E chipset supports quad channel memory.
Good point. Makes me wonder if they'd consider a Threadripper version that uses that chipset, since the Non-Pro Threadripper have been in a weird spot ever since Ryzen went up to 16 cores. An AM5 Threadripper might not make sense because one of the appeals were the much bigger amount of PCIe lanes, but I wonder if they would pair the X870E with a new socket for Zen 5 Non-Pro Threadrippers.
A Threadripper with 24-32 cores but only 2 channels of memory, that worked in the AM5 socket, would fill a nice hole in the AMD story. I don't know if AM5 has enough power pins to do the job, though. If you want more than 16 cores right now you have to spend $2k on the CPU and motherboard, triple what it costs to get a 16-core Ryzen.
I just had a look and the comparison website I use says there are 113 motherboards that support 128GB or more memory for AM5. (in my local market. so the US probably has even more)

128GB isn't exactly a lot, so that would surprise me if it wasnt supported.

I think for a while there, the only way to be able to use 128gb was to go TR4 or TRX... I kindof stopped looking for a while, but 100+ boards is certainly a nice change.
> I just had a look and the comparison website I use

Which website is that?

geizhals.de

Very good website to compare gadgets/electronics and look for good prices.

Its for the German market though (and some small amount of Austrian shops)

skinflint.co.uk is the english-language frontend of the same site
I can’t speak for all motherboards but I’m comfortably running 128GiB of DDR4 on a 5950x and x570s platform.
Good to know, maybe I should look again... thanks
I'm running the same as above. However do check both the memory and motherboard manufacture's tested with lists (QVL qualified vendor list) before purchasing! Each product should have its own compatablity listing.
For AM5 most boards with 4 DIMM slots will support 128 GB, some support 192 GB.
I had 128GB DDR4 3200 running stable on X570 with Ryzen 3000. You should be able to run 192GB these days or even 256GB (but expensive).
Give the server ones a look. 448GB here (one stick out of eight died and I have not been proactive at replacing it). Epyc comes in some SKUs that make a lot of sense for a desktop, or the seriously high spec ones from a previous generation are going cheap.
Kind of a shame, given how cheap 512gb is.

With LLMs, I feel like the line between consumer and professional is getting blurred.

Not that CPU is really reasonable for LLMs that big...