AMD Ryzen 9 7900X Performance With ECC DDR5 Memory

[coder]

So basically we have to stick with CPUs with DDR4 if we want ECC unless we want to pay way more for nothing.

Huh?

We could have DDR5 with proper ECC running at 5400mhz - and that would make Zen 4 CPUs worth it if you can't justify reducing your data integrity... But no, they purposefully omit such products.

Kingston sells ECC DDR5-5600 UDIMMs. Not sure if they're compatible with all motherboards.

There's also a SK Hynix model, but I can't find anywhere to buy it in the US. Not even on aliexpress.

[deusexmachina]

Huh?


Kingston sells ECC DDR5-5600 UDIMMs. Not sure if they're compatible with all motherboards.

There's also a SK Hynix model, but I can't find anywhere to buy it in the US. Not even on aliexpress.

Thanks; I now see the Kingstons... It is unclear if they work at 5200 or are stuck at ~3600, considering AMD's website says this for Zen 4s:

Max Memory Speed:
2x1R - DDR5-5200
2x2R - DDR5-5200
4x1R - DDR5-3600
4x2R - DDR5-3600

Additionally, it isn't clear how much ECC RAM can be used with a Zen 4 before having to reduce the frequency to speeds that aren't worth it. What I said before it that one might as well use a CPU with ECC DDR4 considering the performance, reliability and price ratio (reliability considering "it hasn't been confirmed/tested" and that isn't my job to do, AMD).

[coder]

Thanks; I now see the Kingstons... It is unclear if they work at 5200 or are stuck at ~3600, considering AMD's website says this for Zen 4s:

Max Memory Speed:
2x1R - DDR5-5200
2x2R - DDR5-5200
4x1R - DDR5-3600
4x2R - DDR5-3600

That's saying a 2-DIMMs per channel (sometimes referred to as a 2DPC configuration) will drop it to 3600 MHz. Since there are two "channels", 2DPC means using a total of 4 DIMMs. So, are you planning on using just two DIMMs in the system or would you populate all four slots?

Additionally, it isn't clear how much ECC RAM can be used with a Zen 4 before having to reduce the frequency

Right now, the Kingston DDR5 UDIMMs are available in up to 32 GiB DIMMs. So, the answer is that 64 GiB is the max you can run at 5200 MHz, within spec (i.e. not overclocking).

What I said before it that one might as well use a CPU with ECC DDR4 considering the performance, reliability and price ratio (reliability considering "it hasn't been confirmed/tested" and that isn't my job to do, AMD).

Well, the fastest ECC DDR4 UDIMMs are just 3200. So, they're not as fast as DDR5, though a bit lower latency.

As for reliability, ASRock Rack claims that ECC is fully supported on their AM5 server boards. Supermicro is another option.

[deusexmachina]

That's saying a 2-DIMMs per channel (sometimes referred to as a 2DPC configuration) will drop it to 3600 MHz. Since there are two "channels", 2DPC means using a total of 4 DIMMs. So, are you planning on using just two DIMMs in the system or would you populate all four slots?


Right now, the Kingston DDR5 UDIMMs are available in up to 32 GiB DIMMs. So, the answer is that 64 GiB is the max you can run at 5200 MHz, within spec (i.e. not overclocking).


Well, the fastest ECC DDR4 UDIMMs are just 3200. So, they're not as fast as DDR5, though a bit lower latency.

As for reliability, ASRock Rack claims that ECC is fully supported on their AM5 server boards. Supermicro is another option.

Thank you, that is enough for consideration of doing it despite not seeing it done & verified yet. Need a new system, damn is software getting slow :P