Corsair 2 x 24GB DDR5-7000 Memory Linux Performance

[phoronix]

Phoronix: Corsair 2 x 24GB DDR5-7000 Memory Linux Performance

Corsair recently launched their line-up of 2 x 24GB DDR5 memory kits. With recent DDR5 memory prices falling, for as little as $215 USD it's now possible to obtain 48GB of DDR5-7000 RAM. With this being my first time testing a non-binary DDR5 memory kit, here is an initial look at the Corsair CMK48GX5M2B7000C40 compatibility and performance under Linux.

https://www.phoronix.com/review/corsair-48gb-ddr5-7000

[milkylainen]

Hmm. We're back at feeding the little monsters (nice results).

But... either the CPU is bad at predicting data needs (misses),
or the datasets are increasingly so fat it can't fit a reasonable working set inside modern CPU caches?

Both of the cases would benefit greatly from less latency and increased bw to RAM.

[willmore]

For many of the more demanding workloads, the Corsair DDR5-7000 memory kit was providing some nice advantages over more common DDR5-6000 speeds even with the higher latency of DDR5-7000.

What do you mean higher latency of the DDR5-7000? 40 cycles at 7GHz is less time than 36 cycles at 6GHz. The DDR5-7000CL40 has *lower* latency than the DDR5-6000CL36 memory. Keep in mind that latency values are in cycles, not in some unit of absolute time. CL40 @ 7000 is the same as CL34.29 @ 6000.

[bug77]

Whoaa, at those prices I am tempted to move my 12600k to DDR5. If I can find a decent mobo (I'm picky about those) that won't break the bank.

[avis]

Desktop Zen 4 CPUs don't support/run with DDR5 faster than 6000MHz. Just so you knew. And if you have four DIMM slots populated you're f*cked: only 3600MHz for you.

Strangely mobile APUs support up to LPDDR5x-7500.

[rene]

the quality of PC BIOS' is really sub-par. It took Gigabyte 6 month to get over 5600 MT stable on my X670E Aurus Master AM5 board, ... https://www.youtube.com/watch?v=l1ZUCT7TSWg

[rene]

Desktop Zen 4 CPUs don't support/run with DDR5 faster than 6000MHz. Just so you knew. And if you have four DIMM slots populated you're f*cked: only 3600MHz for you.

Strangely mobile APUs support up to LPDDR5x-7500.

yeah, the PCB traces are also shorter, and directly soldered without socket, ...

[bug77]

I'd be curious to know if CL36@6000 is the best this kit will do or is it just some XMPP pre-baked profile?

[cb88]

Desktop Zen 4 CPUs don't support/run with DDR5 faster than 6000MHz. Just so you knew. And if you have four DIMM slots populated you're f*cked: only 3600MHz for you.

Strangely mobile APUs support up to LPDDR5x-7500.

LPDDR5x-7500 is completely different from DDR5, they just happen to share some text in their nomenclature. They are different in almost every way, different PHY different physical design etc etc...

[pieman]

7000 will never work on zen4. 6000 is its max. you might be able to squeeze up to 6400 but only a small percentage with a lot of heavy tweaking.