Normal DDR5 speed

[PizzaPuntThomas]

What are normal DDR5 speeds for ram. I am looking for parts for Ryzen 7000, and since it uses DDR5 ram, I wondered what would be normal speeds for DDR5. It is of course faster than DDR4, but how much faster is normal. I would say for DDR4 a speed of 3200 or 3600 is normal ram speed (xmp on) but what would those numbers be for DDR5? 

[Alex Atkin UK]

According to AMD, Ryzen 7000 has a sweet spot of DDR5-6000.

[JoHeJo06]

38 minutes ago, Alex Atkin UK said:

According to AMD, Ryzen 7000 has a sweet spot of DDR5-6000.

But you need to buy 32gb of the stuff or you are getting bad performance with 16gb. 

[ewitte]

1 minute ago, JoHeJo06 said:

But you need to buy 32gb of the stuff or you are getting bad performance with 16gb. 

It is a good idea to be on 32GB+ in the first place.

 

I've seen some reasonable prices for DDR5-5600 I would probably go with that if I had to today.

[porina]

Had to look it up since I never recall seeing the officially supported ram speed, which was revealed in the last day to be 5200. Up to that point I could only guess it would be above Intel's 4800.

 

Quote

The Zen 4 parts have a default FCLK of 1,733 MHz, supporting DDR5-5200 memory by default. Hallock believes that DDR5-6000 will be the sweet spot for Zen 4 based on cost, stability, performance, availability, and ease. In contrast, Zen 3's sweet spot was at DDR4-3600 (1,800 MHz FCLK), with DDR4-4000 (2,000 MHz FCLK) being the golden standard. Nonetheless, Hallock said that in some scenarios, when surpassing a 2,000 MHz FCLK could yield better performance. However, it shouldn't be the priority for most users.

https://www.tomshardware.com/news/amd-confirms-ddr5-6000-ram-is-the-sweet-spot-for-ryzen-7000-cpus

 

This seems to be a 3x ratio between FCLK and nominal ram speed, up from 2x for DDR4, although it is also commented that keeping FCLK in sync will be less important. I'm still wondering what the IF arrangement will be. Specifically if single CCD CPUs can make use of two module DDR5 bandwidth or will it be choked internally? 3x multiplier implies they could make IF internally 50% wider than with Zen 3 if they want to keep the data flowing to the cores. The other scenario is single CCD wont be able to make full use of fast ram, with the iGPU as a new consumption.

[Alex Atkin UK]

2 hours ago, JoHeJo06 said:

But you need to buy 32gb of the stuff or you are getting bad performance with 16gb. 

How so?  Amount shouldn't matter.

 

Also, its my understanding DDR5 is dual-channel per-stick, so is there any benefit to two sticks over one?

[Guest]

Just now, Alex Atkin UK said:

Are you sure?  Its my understanding DDR5 is dual-channel per-stick, so is there any benefit to two sticks over one?

16gb dimms are dual channel.

32gb kits for best performance.

 

8gb ddr5 and smaller dimms is similar to ddr4, just higher frequencies.