Dr_b_those timings aren't that bad considering the speed, but is that really worth the premium to run them on AMD @ 8K+ MTs? Would like to see a 2x64 kit @ 6000 with ~CL30 that runs on normal boards

rv8000It’s probably something the realm of 30 gb/s read/write higher than 6000 c30. If you’re actually doing something that require memory bandwidth and you have a dual CCD zen chip, yes.

igormpIn theory that's the bandwidth increase you'd have (2400*128*8000=38.4GB/s), but is Ryzen able to actually make use of that extra bandwidth given the IOD's write/read throughput limitation?
6000MHz alone in theory should be able to cross the 100GB/s mark, but I've only seen a couple cases of heavily overclocked Ryzen CPUs with a really fine fabric tune and 8000MHz+ memory clocks to even reach that mark.
More often than not seems like Ryzen is stuck at the 60~90GB/s mark due to interconnectivity bottlenecks, so I'm not sure if such faster memories would be relevant unless you really want to dig into OC'ing stuff.

rv8000Yea, a Zen 5 user with an apex isn’t touching fclk or memory :kookoo:.

rv80006400/2133 fclk is simple to hit and youre already hitting 100 gb/s read write then.

rv8000It’s probably something the realm of 30 gb/s read/write higher than 6000 c30.

rv8000If you’re actually doing something that require memory bandwidth and you have a dual CCD zen chip, yes.

rv8000Anyone using this kit on an apex or board capable of 8200+ will be tuning fclk and actually be capable of higher bandwidth.

igormpFair enough, but are those users also interested in the extra memory bandwidth? I usually see most people focusing on such OC's/setups for games, not bandwidth sensitive tasks.
And for mosts bandwidth-sensitive tasks, I personally haven't met anyone that goes that hard with only a 2 DIMM motherboard, since they also often need capacity, and thus 4 DIMMs which makes clocks go to shit.


Really? Would you have any easily available example? Most AIDA64 benchs I've seen with people doing some really tight 6000~6400 tunes manage to get close to 100GB/s, but actually never reach this value. I guess max I've seen on overclock.net was like 6600MHz at 98GB/s.
And even the 8000+ setups usually stay in the 100~110GB/s range, I've never seen more than that, even in the AIDA64 thread here:
[EMBED content="thread-186338"]https://www.techpowerup.com/forums/threads/share-your-aida-64-cache-and-memory-benchmark-here.186338/[/EMBED]

Anyhow, bringing back the original point of yours:

My point is just that with even 6000MHz one should in theory reach 96GB/s. 8400MHz should be allowing for ~134GB/s, but I don't think any Ryzen owner will be achieving this in any way, and is more likely to get stuck at the 100~105GB/s range, which is a marginal improvement from the theoretical speeds that even 6000MHz can bring, so...

No actual extra bandwidth, which makes this a bit moot.


Would you mind sharing any case of a Ryzen CPU crossing the 120GB/s mark? I'm really curious to see something like that.

rv8000Some random dual CCD 8000 result randomly pulled from the memory thread

www.overclock.net/posts/29421268/

Vs

Some random dual CCD 6200 result

www.overclock.net/posts/29423679/

Chew and other users have posted significantly higher results closer to/at 120gb/s if memory serves correctly, but I’m not gonna dig through thousands of posts on my phone.

rv8000Chew and other users have posted significantly higher results closer to/at 120gb/s if memory serves correctly, but I’m not gonna dig through thousands of posts on my phone.

igormpThose 2 results point to what I had mentioned, reads for 6200MHz at 92GB/s, and 8000MHz at 103GB/s, both far from the theoretical values, specially the 8000MHz one.
Along with the fact that a 1800MHz increase should translate to almost a 28.8GB/s bump, not 11GB/s. Ryzen's memory scaling is really bad due to the IOD bottleneck.


Gave a quick look at chew's posts, he doesn't seem to do many bandwidth benchmarks, but still their best result seems to be a 106GB/s reads on 8800MHz, which only serves to show that IOD-imposed ceiling on bw.

rv8000Going from 6000c30 to 8000c36 on a dual CCD chip you're gaining ~20 gb/s across r/w/c.

rv8000Stop throwing a bunch of shit at the wall trying to obfuscate

rv8000there are clearly significant marginal bandwidth benefits

rv8000If you don’t wanna spend the money or time, thats on you, and a different story.

igormpAfaik, 103-92 = 11GB/s for the read numbers, which are the most relevant.
Let's not even dive into how bad AIDA64 is for such benchmarks, (mlc ftw), but you shouldn't be cherry-picking the write numbers to try to prove your point, given how unrealistic those are within AIDA64.

You're the one that seem to be throwing a fit and not backing your claims, after I asked for such because I was really wondering if it'd be possible, and it seems like not, from what you're showing so far.

FTFY :p

I don't see how that's relevant to the topic, nor how your assumptions make any sense.

Once again, the claim that such modules are relevant from a bandwidth perspective doesn't seem to hold due to Ryzen's IOD limitations, but such 8400cl44 config may bring benefit in other scenarios still.

rv8000In what world is increasing r/w/c by 12%/17%/19% respectively… marginal?

rv8000If you want a 6000 c30 kit, you can go buy one.

rv8000I’m otherwise unsure why you’re in this thread complaining about arch limits which no one brought up but yourself, and wasn’t being discussed in the original reply.

rv8000It’s probably something the realm of 30 gb/s read/write higher than 6000 c30.