Discussion Speculation: Zen 4 (EPYC 4 "Genoa", Ryzen 7000, etc.)

[Vattila]

Except for the details about the improvements in the microarchitecture, we now know pretty well what to expect with Zen 3.

The leaked presentation by AMD Senior Manager Martin Hilgeman shows that EPYC 3 "Milan" will, as promised and expected, reuse the current platform (SP3), and the system architecture and packaging looks to be the same, with the same 9-die chiplet design and the same maximum core and thread-count (no SMT-4, contrary to rumour). The biggest change revealed so far is the enlargement of the compute complex from 4 cores to 8 cores, all sharing a larger L3 cache ("32+ MB", likely to double to 64 MB, I think).

Hilgeman's slides did also show that EPYC 4 "Genoa" is in the definition phase (or was at the time of the presentation in September, at least), and will come with a new platform (SP5), with new memory support (likely DDR5).

What else do you think we will see with Zen 4? PCI-Express 5 support? Increased core-count? 4-way SMT? New packaging (interposer, 2.5D, 3D)? Integrated memory on package (HBM)?

Vote in the poll and share your thoughts!

 

[DisEnchantment]

Apparently there is new ECO 105 in the BIOS.

I am glad the gaming perf of this CPU is not dominating the 5800X3D, I hope all the gamers wait for the 7800X3D.
I wanna get this 7950X on day 1, the ECO 65 and ECO 105 seems what I would like to try out.

Now I am interested in restricting the chip from hitting too high temps, don't wanna get the fans spinning from too high single core boosts.

No need for TJmax adjustment, and likely no motherboard will support that, just lower the PPT by a bit and you won't be hitting 95C, assuming your cooling isn't anemic.

Actually limiting PPT does not help temps in single core usage cases
Single core boosts are enough to spin up the fans, a high temp on one core will trigger the fans, and I don't like noisy fans.

 

[H T C]

No need for TJmax adjustment, and likely no motherboard will support that, just lower the PPT by a bit and you won't be hitting 95C, assuming your cooling isn't anemic.

I'd say "my cooler is anemic": it's an NH-C14, using only one fan due to RAM compatibility ...

If the boards had a setting where you could change ... say ... up to 10º the TJmax, it would be great: from 95º down to 85º, without changing ANYTHING ELSE in the BIOS (voltages and such). If my reasoning is correct, the CPU would perform exactly like it does in these reviews BUT, instead of a 95º TJmax, it would reach the changed TJmax, with the corresponding performance downgrade and efficiency upgrade.

 

[Markfw]

I will have to say I am slightly disappointed at the temps and watts. As has been pointed out in previous posts, either using -0.1 in vcore or setting 105watt ECO mode substantially reduces heat and barely affects performance. I wish this was default, but I imagine that its to fight Raptor lake.

For my 7950x that I anticipate getting tomorrow, I will try at stock, then try the ECO/vcore changes and see what I will do. As far as performance, its everything I thought it would be. The wattage is still less than Alder lake and most likely Raptor lake, but I want it even better.

 

[coercitiv]

If the boards had a setting where you could change ... say ... up to 10º the TJmax, it would be great: from 95º down to 85º, without changing ANYTHING ELSE in the BIOS (voltages and such).

First of all, you can be sure you'll have the option to enable ECO mode at various lower TDP levels. It's the same idea, a simple switch that lowers power consumption and doesn't require any other special settings.

Personally I'm also reasonably confident there will also be an option to manage the target temperature of the CPU. The fact that you called it TJmax did not help the discussion, as TJmax is a fixed value. What you are likely asking about is something we could call TCase, which is a target temperature one would use to setup TDP calculations. We'll know more about this after tomorrow, when we can at least download motherboard manuals and see available settings.

I can tell you this option existed on AM4 though. I used it on my 1600X build to setup semi-passive cooling, doing essentially what you described: lowered target temperature to 70 or 75C from a stock that I think was 80 or 85C. Do note the 1600X also has a TJmax of 95C, so obviously the target temperature and TJmax were different parameters.

 

[exquisitechar]

https://www.reddit.com/r/rpcs3/comments/xoj8vb

Doesn't look like AVX-512 support makes it particularly fast in RPCS3 right now.

 

[coercitiv]

Doesn't look like AVX-512 support makes it particularly fast in RPCS3 right now.

Folks, anyone who has the 7950X and is unsatisfied with it's RPCS3 performance... do not fret! Just get in touch and I will readily take that CPU off your hands and exchange it with a fine-wine 12700K with AVX512 enabled (early silicon). Get your 30% performance uplift today!

 

[nicalandia]

I will have to say I am slightly disappointed at the temps and watts. As has been pointed out in previous posts, either using -0.1 in vcore or setting 105watt ECO mode substantially reduces heat and barely affects performance. I wish this was default, but I imagine that its to fight Raptor lake.

For my 7950x that I anticipate getting tomorrow, I will try at stock, then try the ECO/vcore changes and see what I will do. As far as performance, its everything I thought it would be. The wattage is still less than Alder lake and most likely Raptor lake, but I want it even better.

Look at what you could do with ECO

 

[DisEnchantment]

Man code compilation gains on Linux are huge (from the perspective of 5950X owner)

AMD Ryzen 9 7900X / Ryzen 9 7950X Benchmarks Show Impressive Zen 4 Linux Performance Review - Phoronix

www.phoronix.com

Developers rejoice!!

 

[igor_kavinski]

Can you answer any of these questions to support that AMD made a mistake with their TIM?

I'm not a TIM expert but 20 degrees celsius is a huge difference. Something somewhere is not right. Yes, pointing at just TIM may well be naive of me.

 

[H T C]

The fact that you called it TJmax did not help the discussion, as TJmax is a fixed value.

I thought i was using the correct term: my bad then.

I was referring to the max temp the CPU will get: it was 95º in GN's review, and they stated this would be so, REGARDLESS of the cooler used.

THIS is the value i wanted to be possible to change in the BIOS.

 

[In2Photos]

For those complaining about temps and power draw think of Zen4 like you do a car. Buying one with 300+ HP CAN consume a lot of fuel IF you keep your foot on the throttle. But if you don't you will see much better fuel economy. The power is there if you want/need it.

 

[nicalandia]

For those complaining about temps and power draw

For those complaining of Power Draw. Just look at this.

 

[eek2121]

One observation I made watching the GN reviews and reading others is that there is the possibility that per core undervolting may cause larger improvements in performance than it did with Zen 3. It will be interesting to see what happens when users get the chips.

Hoping to order mine ASAP.

 

[Abwx]

Doesn't look like AVX-512 support makes it particularly fast in RPCS3 right now.

Because :

https://twitter.com/x/status/1574398461642174464

 

[DisEnchantment]

I was referring to the max temp the CPU will get: it was 95º in GN's review, and they stated this would be so, REGARDLESS of the cooler used.

THIS is the value i wanted to be possible to change in the BIOS.

Same mate, same. I want to bring down temps, because I hate fan noise and heat, it interferes with my concentration. I don't really care if it use 300W or more.
I just need some BIOS option that says throttle when hitting 85 degrees or something like that.
Even on ECO mode my 5950X trigger fan noise, the only way I stopped that is by disabling boost.

Actually I wanna try to just disable boost on 7950X, since I run all core like 75% of the time and the base is already really high at 4.5GHz.

 

[exquisitechar]

Because :

https://twitter.com/x/status/1574398461642174464

It was tested with a custom build that had AVX-512 enabled, check the comments of the guy that posted it

 

[Hitman928]

I'm not a TIM expert but 20 degrees celsius is a huge difference. Something somewhere is not right. Yes, pointing at just TIM may well be naive of me.

TIM isn’t the only factor but it’s a big one. The problem with your post is assuming AMD made a mistake with the TIM when they’re using the best commercially viable solution available to them.

 

[yuri69]

Well, no surprise in gaming workloads. Even those brutal PBO beasts struggle to beat the old Zen 3 with V-Cache or old 12900K.

Gamers should buy cheap AM4 + 5800X3D, Intel, or wait for Zen 4 + cache.

 

[inf64]

Btw UB still hasn't enabled Ryzen 7000 in their "ranking" list, even though NDA has been lifted. The cpupro guy seem to be very butthurt

Here is the hidden Zen 4 hype train 7950X Vs the 13900K, a CPU that hasn't been even previewed officially but yet IS in the ranking list:

UserBenchmark: AMD Ryzen 9 7950X vs Intel Core i9-13900K

 

[In2Photos]

Would AMD have been chastised more for requiring a new cooler or for having temps where they are? With some coolers not compatible due to the backplate I'm thinking maybe they should have ditched compatibility for better thermals.

 

[therealmongo]

Btw UB still hasn't enabled Ryzen 7000 in their "ranking" list, even though NDA has been lifted. The cpupro guy seem to be very butthurt

Here is the hidden Zen 4 hype train 7950X Vs the 13900K, a CPU that hasn't been even previewed officially but yet IS in the ranking list:

UserBenchmark: AMD Ryzen 9 7950X vs Intel Core i9-13900K

I cannot imagine what is going through their minds right now 😂

 

[Bigos]

The 230W PPT setting would make sense for 24+ core SKUs, if they were to exist. Currently, 7950X @ 230W is like 5800X @ 142W - if you limit the latter to 88W (aka make it 5700X) you won't notice a thing.

Maybe AMD is planning on introducing such higher-core-count SKUs? But that might be in 2 years in the form of Zen 5...

 

[inf64]

Igor's lab gaming summary for 720p (trying to force CPU bottleneck): https://www.igorslab.de/en/a-new-er...iew-with-gaming-and-workstation-benchmarks/3/


They tested both AMD and intel with DDR5 6000 CL30, coupled with 6950XT and all on Windows 11 Pro 2H22.

 

[Det0x]

Temperature scaling testing

 

[Paul98]

The 230W PPT setting would make sense for 24+ core SKUs, if they were to exist. Currently, 7950X @ 230W is like 5800X @ 142W - if you limit the latter to 88W (aka make it 5700X) you won't notice a thing.

Maybe AMD is planning on introducing such higher-core-count SKUs? But that might be in 2 years in the form of Zen 5...

That's what I am expecting, it gives they much more headroom moving forward that they didn't have with AM4