AMD Smart Access Memory Can Work with First-Gen Ryzen CPUs

Tsing

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We previously reported on a rumor suggesting that AMD’s new Smart Access Memory (SAM) feature would only work with Ryzen 5000 Series processors due to the way older chips handled a particular instruction (PDEP), but it turns out that isn’t the case at all. Following an official response from AMD confirming that SAM doesn’t depend on PDED, an ASUS B450-PLUS motherboard user has discovered that the feature can be enabled with an AMD Ryzen 7 1700 processor.



Got a response from AMD about PDEP and SAM:‘Smart Access Memory does not depend on the performance of the PDEP instruction.’The speculation about accelerated PDEP on Zen3...
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I really think you need a card that is PCIE 4.0. I don't KNOW this but it seems to make sense to me.
 
Grimlakin said:
I really think you need a card that is PCIE 4.0. I don't KNOW this but it seems to make sense to me.
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Yeah, testing with a card that's 3 generations old doesn't give useful data for this.
 
Well, AMD even said it would work, it's just that the way the Zen and Zen2 CPUs implemented Resizable BAR was via microcode emulation, not with a specific native instruction, so it didn't add any speed benefit like it does in Zen3.

I had a source link in another post here, but I haven't had enough coffee yet this morning to go digging for it now.
 
I installed it, and **** it I am trying it out. So far not noticing any differences. On bios 3003 for my current board.
 
I hadn't heard of this PDEP thing.

All along the official line I had heard was that it was a matter of board/chipset validation, and that they current guarantee that motherboard vendors would properly validate older boards to make sure the feature worked, so they decided to phase it in on the latest chipset and CPU's only.

I'm hoping it will work on my TRX40 Threadripper 3960x.
 
So it CAN work in an academic way.., just makes it worse....
So it just doesn't work in any practical sense, basically yes, you need new stuff as told..
Yet people will just complain and complain each time...
Im starting to see a point to Intels you need a new mobo per each microcode update... Or we will just change a single power pin so there! Attitude.
 
I see a bios update for the B450 board, maybe one day I can stuff a 5600x in it. <shrugs>
 
Asus B450 took the bios update, now wont run ram at 3200.... Tinker it is
 
with ASRock anyways .. on both x570 Steel Legend and Taichi .. anything above AMD AGESA Combo-AM4 V2 1.0.8.0 with 3000 series Ryzen (only chips I have to test with) ..memory timings/stability above XMP has been abysmal.. and quite a few are having issues running even XMP profiles stably.

As soon as Newegg gets a 5900x in stock .. I'll grab one and see if it's a different ball game with 5000 series.

I don't like the idea of a "trade-off" .. do I want my RAM to run faster .. or do I want access to SAM functionality ... :unsure:
 
ThreeDee said:
I don't like the idea of a "trade-off" .. do I want my RAM to run faster .. or do I want access to SAM functionality ... :unsure:
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Well... Unless you have a Zen3 chip, it's no tradeoff at all. You don't want SAM, it won't do you any good.

If you have a Zen3 though (and a GPU that can use it), would you be making that trade? Doesn't Zen3 have better RAM stability than previous generations anyway? Not saying that trying to defend AMD or anything, I honestly don't know the answer to the question.
 
Brian_B said:
Well... Unless you have a Zen3 chip, it's no tradeoff at all. You don't want SAM, it won't do you any good.

If you have a Zen3 though (and a GPU that can use it), would you be making that trade? Doesn't Zen3 have better RAM stability than previous generations anyway? Not saying that trying to defend AMD or anything, I honestly don't know the answer to the question.
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That's my question though .. when Newegg finally takes my money and I have my shiny new 5900x and 6800 .. will the newer BIOS's be stable all of a sudden with my 3200 CAS 16 RAM @ 3600 CAS 16 ..? Were not talking huge improvements/losses here .. but improvements and losses none the less..
 
ThreeDee said:
That's my question though .. when Newegg finally takes my money and I have my shiny new 5900x and 6800 .. will the newer BIOS's be stable all of a sudden with my 3200 CAS 16 RAM @ 3600 CAS 16 ..? Were not talking huge improvements/losses here .. but improvements and losses none the less..
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Well, in that case - there is no trade off. You don't have the option of running the older BIOS with the newer CPU, do you? You'll take the newer BIOS and like it, and you'll get what you get on the RAM.

Given that the memory controller is baked into the CPU (well, not the CPU chiplets, but on the package)-- yeah, the BIOS certainly affects it, but once you throw the new CPU into the mix, you've just rolled all the dice again on what the system can clock up to has a whole.
 
1. Update AMD AGESA Combo-AM4 V2 1.0.8.0
2. Support AMD Ryzen™ 5000 Series processors

.. but no SAM support (I don't think .. I'll have to dig through my BIOS .. maybe it's there, just greyed out)

..just all the updates after 1.0.8.0 ..on Ryzen 3000 anyways .. makes your memory take a dive
 
ThreeDee said:
1. Update AMD AGESA Combo-AM4 V2 1.0.8.0
2. Support AMD Ryzen™ 5000 Series processors

.. but no SAM support (I don't think .. I'll have to dig through my BIOS .. maybe it's there, just greyed out)

..just all the updates after 1.0.8.0 ..on Ryzen 3000 anyways .. makes your memory take a dive
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Ah ok, thanks for explaining. Hmm ... good luck then. Could be interesting to see the results. Can you still roll back BIOS revisions?
 
I'm always hopping in between BIOS versions .. try a new one .. flash back if I don't like it
 
I will have to roll back my Asus board. It has a few quirks and won't do XMP anymore. Will not run the ram beyond 2133.

I will wait till I get a 5600x and reflash to this newer bios.
 
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