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Comment by mort96

9 hours ago

Got it running with 4800MT/s and literally 30 minute boot times in an AM5 machine. The 30 minute boot time could be worked around by enabling the (off-by-default) memory context restore option in BIOS, but it really made me think something was broken and it wasn't until I found other people talking about 30 minute boot times that I stopped debugging and just let it sit for an eternity.

It's so bad. I don't get why they sell AM5 motherboards with 4 RAM slots.

At least that system has been running well for like two years. But had I known that the situation is so much more dire than with DDR4, I would've just gotten the same amount of RAM in two sticks rather than four.

12 comments

mort96

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WD-42  7 hours ago

I’m in the same situation! My machine will take 2-5 minute to post every few reboots, it seems random. The messed up part is the marketing material says this things can handle 256gb of ram or whatever absurd number, f me for thinking then 128gb should be no problem. Honestly this whole thing has soured me on AMD. Yea they have bigger numbers than intel but at what cost, stability?

  • noir_lord  5 hours ago

    Check you have MCR (Memory Context Restore) enabled, otherwise you train the RAM way more often than you need to (every boot).

noir_lord  5 hours ago

You need to enable MCR (which trains the memory once and caches the result for (iirc) 30 days) otherwise yeah, booting is horribly slow, even the 64GB I have can take several minutes but with MCR it boots basically instantly.

Some motherboards have it off by default.

  • mort96  2 hours ago

    From my comment:

    > The 30 minute boot time could be worked around by enabling the (off-by-default) memory context restore option in BIOS

  • kenhwang  5 hours ago

    Memory training seems to be getting faster with each bios update. In 2024 when I upgraded to AM5, 64GB memory training took like 15 minutes. Now the same setup takes about a minute when it needs to retrain, then near instant with MCR (Windows 11 takes significantly longer to load than the POST process).

secondcoming  7 hours ago

Your machine takes 30 minutes to boot because of the RAM? Or it takes 30 minutes to load a model?

  • WD-42  7 hours ago

    It's the RAM. It needs to "trained" which takes some time but for for some reason these boards seem to randomly forget their training, requiring it to happen again.