News AMD Confirms DDR5-6000 RAM Is The Sweet Spot For Ryzen 7000 CPUs

thisisaname

Distinguished
Feb 6, 2009
434
175
18,860
0
Hmmm so AMD only guarantees DDR5-5200 support on a 1DPC (DIMM per channel) configuration. In a 2DPC scenario, the official memory speed drops to DDR5-3600.
Two things spring to mind if the sweet spot is DDR5-6000 the grantee supported speed is only 5200 does seem a little low and 2DPC speed of only 3600 is very slow. I wonder how much that is going to affect proformance.
 

shady28

Distinguished
Jan 29, 2007
385
244
19,090
8
Hmmm so AMD only guarantees DDR5-5200 support on a 1DPC (DIMM per channel) configuration. In a 2DPC scenario, the official memory speed drops to DDR5-3600.
Two things spring to mind if the sweet spot is DDR5-6000 the grantee supported speed is only 5200 does seem a little low and 2DPC speed of only 3600 is very slow. I wonder how much that is going to affect proformance.

I think this is going to wind up being just like their "Zen 3 works best at DDR4-4000" thing. Most can get to 3600 (not all), many can get to 3800 (but fewer), but 4000 is like less than 5% of Zen 3 owners.

Next sneaky move would be to make sure reviewers are also provided with 'binned' high quality chips.
 

tommo1982

Distinguished
Dec 5, 2010
136
50
18,660
0
I'm confused. Isn't DDR5 inherently double channel? Two modules will make it quad channel, right? I hope it will explained in the review. I'm lost in all of this.
 

wifiburger

Honorable
Feb 21, 2016
607
102
11,190
9
5200 default speed is 1 dimm,
2 dimms drops to 3600 speed and their support page don't even support 4 dimms by default

to me it looks like the IMC is crap, typical AMD of course

"sweet spot" BS from AMD; I will believe when 99.9% of Zen4 samples hit ddr6000

people thinking IF goes to 3000mhz when AMD said ddr6000....... lol


Now, let's do some calculations, because why does AMD list 5200 1 DIMM & 3600 2 DIMM by default ?

1733mhz IF x 32 bits = 55.4Gb/s bandwith
5200 1 dimm bandwith = ~41.6Gb/s
3600 2 dimm bandwith = ~57.6Gb/s
5200 2 dimm bandwith = ~83.2Gb/s

I'm assuming you still reach 83.2Gb/s with 5200 2 dimms with 1733IF clock ?
I guess there's some changes to async operations or IF is 64bits per clock ?
 
Last edited:
Reactions: shady28 and KyaraM
5200 default speed is 1 dimm,
2 dimms drops to 3600 speed and their support page don't even support 4 dimms by default

to me it looks like the IMC is crap, typical AMD of course

"sweet spot" BS from AMD; I will believe when 99.9% of Zen4 samples hit ddr6000

people thinking IF goes to 3000mhz when AMD said ddr6000....... lol


Now, let's do some calculations, because why does AMD list 5200 1 DIMM & 3600 2 DIMM by default ?

1733mhz IF x 32 bits = 55.4Gb/s bandwith
5200 1 dimm bandwith = ~41.6Gb/s
3600 2 dimm bandwith = ~57.6Gb/s
1 DIMM PER channel. And it's going to be dualchannel motherboards, just as we have with DDR4. So that means 2 DIMM sticks.
What I am seeing is, just like with quadrank per channel on AMD and DDR4, it's going to run like crap.
 
Reactions: thisisaname

wifiburger

Honorable
Feb 21, 2016
607
102
11,190
9
I'm confused. Isn't DDR5 inherently double channel? Two modules will make it quad channel, right? I hope it will explained in the review. I'm lost in all of this.
1 dimm ddr5 = dual channel ddr5 (half bandwidth) = same as 1 dimm ddr4 single channel full bandwidth

2 dimm ddr5 = qual channel ddr5
it's the same as 2 dimm dual channel ddr4 for bandwidth
 
Reactions: tommo1982
Hm... I don't like having to rely on the motherboard to set the IF speeds. That being said, I'll wait for reviews to show if this has any meaningful impact or not.

I was hoping for 3Ghz IF. Bummer.

Regards.
 

tommo1982

Distinguished
Dec 5, 2010
136
50
18,660
0
Hm... I don't like having to rely on the motherboard to set the IF speeds. That being said, I'll wait for reviews to show if this has any meaningful impact or not.

I was hoping for 3Ghz IF. Bummer.

Regards.
Where do you set IF speeds? Haven't seen the option anywhere in my BIOS. I have a Ryzen 5 Pro 3350G, so I might be unable to set it manually. I also have an ASRock B450M Steel Legend.
 

tommo1982

Distinguished
Dec 5, 2010
136
50
18,660
0
1 dimm ddr5 = dual channel ddr5 (half bandwidth) = same as 1 dimm ddr4 single channel full bandwidth

2 dimm ddr5 = qual channel ddr5
it's the same as 2 dimm dual channel ddr4 for bandwidth
How will the mainboard deal with four RAM slots occupied? Will it run as quad chanell with one DIMM full bandwith per chanell like DDR4?
 
Where do you set IF speeds? Haven't seen the option anywhere in my BIOS. I have a Ryzen 5 Pro 3350G, so I might be unable to set it manually. I also have an ASRock B450M Steel Legend.
I don't know how it is called in AsRock BIOS'es, but you can find the "FCLK" (fabric clock) or "BCLK" (bus clock). Don't confuse it with the memory speed though.

And, when in doubt, RTFM.

Regards.
 

TJ Hooker

Champion
Ambassador
I'm confused. Isn't DDR5 inherently double channel? Two modules will make it quad channel, right? I hope it will explained in the review. I'm lost in all of this.
Technically yes, each 64 bit DIMM is split into two 32-bit channels for DRR5. But as far as I can tell, everyone is still referring to the full 64-bits as being a single channel. E.g. both Ryzen 7000 and Alder Lake are listed as having two memory channels, but they are 2 x 64 bit, not 2 x 32 bit.

TL;DR you can probably treat DDR5 as working the same as DRR4 in terms of channels, as that is how manufacturers are treating it.
 
Reactions: tommo1982

ASK THE COMMUNITY

TRENDING THREADS