AMD Zen 3 (5000 Series), rumored 17% IPC gain.

[humbug]

Has there been any talks on memory latency reduction or is this just simply an IPC and clock speed increase release? e.g. will we see Zen3 memory latency under say 55ns?

You're not going to see a "Memory Latency" reduction with Zen 3 if Zen 3 is still a chiplet design.

The IMC (Integrated Memory Controller) is External to the cores and Cache, its on the IO, its that distance the data need to travel which result in the higher memory latency.

Having said all of that Memory Latency seems to be irrelevant, its not the Memory Latency that's the cause of Ryzen reduced IPC in games vs productivity, that's cause by "intercore latency" Zen 2 consists of two core clusters with 4 cores and 16MB of L3 cache in each, if a core in one CCX wants to communicate with a core in another CCX there is latency as it need to jump across core clusters, that is the cause of the Gaming IPC discrepancy.

Where the game only uses a couple of cores its fine as it can keep the work in one CCX, like CS:GO, game that are more than 4 cores is where the problem is

For example CS:GO below that's pretty good performance and at the IPC level you would expect from Cinebench or Handbrake.

Spoiler: CS:GO

However: the 3300X is unique in that it takes it 4 cores from a singular CCX, the result of that is the gaming IPC is again very high, higher than Zen 2 ordinarily is, so far YesTechCity, Hardware unboxed and GN have investigated this, YesTechCity and Hardware Unboxed found +7% at the same clock speed vs the otherwise identical 3100, steve from GN found one with 14% higher IPC.


The thinking is Zen 3 at least will have single 8 core CCX chiplets.

 

[LePhuronn]

The thinking is Zen 3 at least will have single 8 core CCX chiplets.

8 core CCX with 32MB L3 cache shared across the entire chiplet. That's rumoured to bring an average 15% IPC bump.

 

[RavenXXX2]

Zen 3 needs to address the high DDR latency to really put it to Intel in gaming.

 

[humbug]

Zen 3 needs to address the high DDR latency to really put it to Intel in gaming.

Read what i said, its not the DDR latency that the cause, its intercore latency.

 

[humbug]

With the 3300X AMD are giving us a cheeky glimpse of what's coming

 

[RavenXXX2]

Read what i said, its not the DDR latency that the cause, its intercore latency.

It's not, that's a tiny part, going 8 core CCX is not going to make a big difference. The 3100 is massively gimped with games having to jump across 2 x 2 core CCX.

 

[humbug]

It's not, that's a tiny part, going 8 core CCX is not going to make a big difference. The 3100 is massively gimped with games having to jump across 2 x 2 core CCX.

Look at the slides, +7% - +7% - +14%

In Fortnight at 4.575Ghz the 3300X is faster than a 3950X which boost to about 4.6Ghz, its faster than a 9900KS which boost to about 5.2Ghz.

In F1 2019 at 4.4Ghz its as fast as an 8 core 3700X which boosts to 4.4Ghz, its as fast as the 9600K / 7700K at 5.1Ghz.

Tuning the IF and memory on the 3100 made a difference but nothing like enough to catch the 3300X, tuning the IF and memory on the 3300X made no difference.

Its not the memory, tuning it on normal Zen 2 does help but nothing like having the cores in a single CCX. that's intercore latency.

 

[BongoHunter]

Will these work on B450? I have a spare Asrock B450 Pro 4 sat doing nothing

 

[humbug]

Will these work on B450? I have a spare Asrock B450 Pro 4 sat doing nothing

Zen 3? no...

Edit: 3300X yes...

 

[Perfect_Chaos]

Read what i said, its not the DDR latency that the cause, its intercore latency.

I thought Hardware Unboxed said in a recent video that it was memory latency they need to get down, though on their site they seem to mention the intercore latency instead so bit confusing.

 

[humbug]

I thought Hardware Unboxed said in a recent video that it was memory latency they need to get down, though on their site they seem to mention the intercore latency instead so bit confusing.

I think Steve is mixing Memory Latency with Intercore Latency.

Proof of what it is is in the pudding, we now have that pudding in the form of the 3300X, its the only Zen 2 CPU that doesn't take cores from more than one CCX and per core per clock its easily the fastest Zen 2 gaming CPU, the memory latency on it is exactly the same as all other Zen 2 CPU's, it will be, it still has its IMC on the IO die.
The only difference between the 3300X and the 3100 is the 3300X is a single CCX while the 3100 like all other Zen 2 CPU's has multiple CCX's, they have the same 4 core 8 thread 16MB L3 cache.

I like to think AMD did this quite deliberately as a cheeky show and tell and to tease us, give us something to talk about.

Its a Zen 3 half step

 

[humbug]

To me that hint has always been there, accidentally. Ironically very low threaded games like CS:GO have always done very well on Zen 2, the only reason that can be is because CS:GO being a DX9 game is low threaded enough to keep the work inside a single CCX where there are only 3 or 4 cores available.

 

[LePhuronn]

*my 6700K weeps in the corner*

 

[CAT-THE-FIFTH]

Well once the Zen2 APUs are in a desktop form,we can see how their performance is - if memory-CCX latency is a problem,they should do better in games which are not L3 cache dependent.

 

[humbug]

*my 6700K weeps in the corner*

Poor thing.... my 3600 is also looking at the 3300X thinking.... Aww crap my days are numbered

 

[LePhuronn]

I'll be honest, I'm not too bothered so far. I've had the 6700K for a few years now, but because it was going into my big Asteria II project the Impact 8 board was always in and out for testing and measuring, and I could never actually use it as a computer. I've only started using it full time now on a test bench (project still is nowhere near done) and it's such a leap over the 2500K it's like a fresh machine.

I just want all the shiny shiny new stuff

 

[humbug]

I'll be honest, I'm not too bothered so far. I've had the 6700K for a few years now, but because it was going into my big Asteria II project the Impact 8 board was always in and out for testing and measuring, and I could never actually use it as a computer. I've only started using it full time now on a test bench (project still is nowhere near done) and it's such a leap over the 2500K it's like a fresh machine.

I just want all the shiny shiny new stuff

The 7700K is a rebranded 6700K, the latter just doesn't clock as high but both CPU's are still very capable, its just a shame they cost so much when new, for a 4 core 8 thread CPU.

 

[LePhuronn]

I landed a bargain for my 6700K, was £190 new around June 2016.

I'm very tempted to try out the modded BIOS for the Impact 8 that can run a 9900K, but given Intel CPUs never drop in price, I'm not sure I fancy doing jumps on the pads of a £500 CPU

 

[humbug]

Another way we can put this, i think, the 3300X is effectively Zen 2 with a Ring Bus.....

Edit: If that doesn't make people go "Ah, now i get it...." i don't know what will

 

[Joxeon]

Another way we can put this, i think, the 3300X is effectively Zen 2 with a Ring Bus.....

Edit: If that doesn't make people go "Ah, now i get it...." i don't know what will

It still lost to the 7700k in all the tests though so a scaled up 8 core version would still be behind the 9900k.

And also the ryzen is being run with 4x 8gb of 3200/14 ram which most people buying a £120 CPU will not spend £250 on ram.