ECC DDR5-4800 vs. DDR5-5200 Memory Performance For AMD Ryzen Zen 4

[phoronix]

Phoronix: ECC DDR5-4800 vs. DDR5-5200 Memory Performance For AMD Ryzen Zen 4

Back when looking at the AMD Ryzen 7000 series budget server performance last year, DDR5-4800 ECC UDIMMs were used with the ASRock Rack 1U4LW-B650/2L2T Ryzen server given that's what was broadly available at the time. Since then there's been more ECC UDIMMs coming to market above DDR5-4800 speeds. Recently I bought a pair of Kingston Server Premier 32GB 5600MT/s DDR5 ECC CL46 UDIMMs (KSM56E46BD8KM-32HA) and that's the focus of today's tests. For those curious if the faster ECC UDIMMs are worthwhile compared to the commonality of DDR5-4800 ECC UDIMMs, these benchmarks are for you.

https://www.phoronix.com/review/amd-ryzen-ecc-ddr5-5200

[omegaone]

The Infinity Fabric was the same on both speeds?

On my motherboard if I use 4800MTs the FCLK is at 1800MHz, but at 5200MTs the FCLK goes to 2000MHz, automatically selected by the motherboard.

FCLK has a bigger impact than MCLK.

[bug77]

For the life of me, I cannot understand why would anyone buy RAM that's less than 10% faster than the one they already own... Or CPU, GPU or SSD for that matter.

[pWe00Iri3e7Z9lHOX2Qx]

When I built my new Zen 4 system I was hoping to get a (non-ECC here) DDR5-6400 96GB kit since that's the fastest my mobo can do with two dual rank DIMMs. But the only 96GB kit at that speed was $400 USD. I picked up a Crucial DDR5-5600 96GB kit for $217. It would be nice if you could easily get single rank DIMMs with densities higher than 24GB. Before anyone drops a lot of money on memory, double check what speeds your mobo supports in terms of DIMMs per channel and rank configuration. E.g. mine...

• 1DPC 1R Max speed up to 7800+ MHz
• 1DPC 2R Max speed up to 6400+ MHz
• 2DPC 1R Max speed up to 6400+ MHz
• 2DPC 2R Max speed up to 5400+ MHz

So if I want 192GB of RAM, there's no point in going over DDR5-5400 unless a faster kit is cheaper or if I want them to be hand me down DIMMs in other 1DPC systems eventually.

[pWe00Iri3e7Z9lHOX2Qx]

Also, thank goodness we are getting DIMMs over 32GB finally. It feels like forever ago that server platforms got 128GB DDR4 ECC DIMMs. 48GB on the consumer side is a nice first step, but hopefully we get 64GB DIMMs soon.

[sophisticles]

For the life of me, I cannot understand why would anyone buy RAM that's less than 10% faster than the one they already own... Or CPU, GPU or SSD for that matter.

I don't think anyone is upgrading their hardware, or even their software stack, just for a 10% bump in performance.

There are people that will pay a lot more for 10% faster hardware when building a new system from scratch.

I personally just set a target price per piece of hardware, like $200 max for CPU, $200 max for GPU, $100 max for ram, $100 ,ac for motherboard, and in fact I usually look for a left over model from HP or Dell that I can upgrade on the cheap.

[loganj]

NASA's NPB benchmarks

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