Question Zen2, making a 16/12 core CPU process like an 8/6 core to get higher clocks on the fly?

[Kedas]

Hi,

The operating system can't handle cores/threads that disappear very well without reboot.
If you set 'gamer mode' ('use less cores') on you have to reboot to get the higher clock for the same power.

I was thinking for Zen2 could they maybe implement something to do that on the fly?
The operating system keeps seeing 16/12 cores you can't rely on Microsoft to solve that, but what if they in silicon design can reroute the workload of the 8/6 other cores to the first die.

It may be similar like one Zen2 core getting 4 threads to process instead of 2 (like a rumor in the past) but on a higher freq since the other die is sleeping, maybe something for Zen3....

or maybe the I/O die has some virtualization layer for the threads and they can just reroute on the fly 2 virtual to 1 real without problem.

 

[Yotsugi]

What you actually want is some agressive turbo tables.
Which you will in fact get.

 

[Kedas]

It's not the same as turbo tables and your minimum clock will always be lower with turbo tables, 8 cores that are sleeping are different.

 

[Yotsugi]

It's not the same as turbo tables

You'll get the same effect by having an agressive turbo table with agressive 8c boost clocks.
Modern power gating is very good!

 

[Topweasel]

Game mode is only useful for Threadripper and a handful of games that don't like SMT (read old).

You don't use it on Ryzen for gaming unless you absolutely need to and won't be required on Ryzen 3k and there is an increased likelihood that you won't need it for TR3 either (do to how the io chip will work).

 

[whm1974]

OK someone please explain to me why we need a 12 or 16 core CPU for gaming? Why not get a higher clocked 6 or 8 instead?

 

[Yotsugi]

Why not get a higher clocked 6 or 8 instead?

You're assuming AMD will sell you a higher clocked 6/8c part.
Which of course they won't, just like any vendor they'll try their hardest to gravitate you towards the higher ASP parts.

 

[Topweasel]

OK going to sound like a douche, But dude not every CPU is for gaming and even if people game a lot they do more than just game on their systems.

That said you can reach a limit of how much faster the cores can run if you remove more of them. More times than not it's not a process limit but a power limit. If AMD can fit 16 pretty fast cores for the same power envelope of the previous gen then it's a win for everyone. But AMD will have 8 core Ryzen 3 CPUs.

 

[whm1974]

OK going to sound like a douche, But dude not every CPU is for gaming and even if people game a lot they do more than just game on their systems.

That said you can reach a limit of how much faster the cores can run if you remove more of them. More times than not it's not a process limit but a power limit. If AMD can fit 16 pretty fast cores for the same power envelope of the previous gen then it's a win for everyone. But AMD will have 8 core Ryzen 3 CPUs.

I'm well aware people do a lot more then game on their systems. However very few people actually need or will even benefit from having more then 6c/12t or 8c/16 threads.

 

[Kedas]

I want more cores for data processing but I also would prefer if I don't have to reboot for VR/games.
It's not only clocks that have an impact for VR/games you also have cache on two different dies that is making things slower, letting one die sleep like in gamer mode fixes that.
You talk about threadripper but I'm talking about AM4 16 cores.

Do you really think that the 16 core on AM4 wont have a gamer mode?
(the setup is very similar like threadripper now)

 

[Yotsugi]

Do you really think that the 16 core on AM4 wont have a gamer mode?

Why would it?

(the setup is very similar like threadripper now)

The what?
There's no far memory in anything Zen2 unless it's 2P Rome.

 

[Topweasel]

I'm well aware people do a lot more then game on their systems. However very few people actually need or will even benefit from having more then 6c/12t or 8c/16 threads.

So? I am not going to tell everyone to get a 16c CPU, though I really really recommend people stop buying stuff less than 6c12t. But how does there being a 16c option affect you? There will be a 8c part and I doubt 16c affect clocks more than 100-200MHz. For the people who want the cores that's a good trade-off.

 

[maddie]

I'm well aware people do a lot more then game on their systems. However very few people actually need or will even benefit from having more then 6c/12t or 8c/16 threads.

The new consoles, if they go to 8 SMT cores and the game engines for them should be able to use more threads. I mentioned a while ago that it's possible that for gaming, you might want as a minimum, 16 threads in a few years. 6C/12T might be basement models then. You're basing your expectations of the future with present models. Unwise in my opinion.

 

[TheELF]

The new consoles, if they go to 8 SMT cores and the game engines for them should be able to use more threads. I mentioned a while ago that it's possible that for gaming, you might want as a minimum, 16 threads in a few years. 6C/12T might be basement models then. You're basing your expectations of the future with present models. Unwise in my opinion.

Lol,the new consoles will be 4k which means that they won't even be able to use 8smt cores, the GPU will cut them off way before that.
Just as with the current consoles we will get two mobile ryzen APUs with redesigned gpus,so two 200ge (or zen 2 equivalent)for a total of 8 threads with a big IPC increase over jaguar even if they go for the same clocks.

 

[Topweasel]

Lol,the new consoles will be 4k which means that they won't even be able to use 8smt cores, the GPU will cut them off way before that.
Just as with the current consoles we will get two mobile ryzen APUs with redesigned gpus,so two 200ge (or zen 2 equivalent)for a total of 8 threads with a big IPC increase over jaguar even if they go for the same clocks.

Ehhh. I think you a missing one big key that has crippled game development over the last decade or so. CPU resources for other parts like AI. AI took a major step back when game development transitioned to the X360 and PS3. It has never really recovered because even with 8 cores now they are super slow. If they did 8 Zen cores it would give them tons of more room for AI, Physics, world destruction, and more. So while the GPU might tap out using Zen and the proliferation of 4+ core systems on PC, might see some lost art re-enter our games and find that CPU choice might once again have a real effect on how our games run.

 

[TheELF]

Ehhh. I think you a missing one big key that has crippled game development over the last decade or so. CPU resources for other parts like AI. AI took a major step back when game development transitioned to the X360 and PS3. It has never really recovered because even with 8 cores now they are super slow. If they did 8 Zen cores it would give them tons of more room for AI, Physics, world destruction, and more. So while the GPU might tap out using Zen and the proliferation of 4+ core systems on PC, might see some lost art re-enter our games and find that CPU choice might once again have a real effect on how our games run.

You are confusing the devs with someone that cares about that...
If they cared about that at all they would have pushed for stronger cores back when game development transitioned to the X360 and PS3 instead of pushing for x86 cores because lazier porting.

Yes better cores would give them the possibility for better games but that's the last thing they care about,as long as it looks stunning they are set.

 

[Kedas]

Kedas said:


(the setup is very similar like threadripper now)

The what?
There's no far memory in anything Zen2 unless it's 2P Rome.

So do we have a 16 core threadripper with only 2 memory channels used both on 1 die, to compare?

 

[Markfw]

So do we have a 16 core threadripper with only 2 memory channels used both on 1 die, to compare?

We have nothing to compare, since Ryzen 3000 series uses an IO die and a core die(s). We will find out then they come out.

 

[Topweasel]

You are confusing the devs with someone that cares about that...
If they cared about that at all they would have pushed for stronger cores back when game development transitioned to the X360 and PS3 instead of pushing for x86 cores because lazier porting.

Yes better cores would give them the possibility for better games but that's the last thing they care about,as long as it looks stunning they are set.

It's a fight between many factors including power usage and price. Keep in mind that when these were being developed originally the only legitimate option without requiring AMD or Intel or IBM to start from scratch was what IvyBridge? It would have been 4 cores with a high power envelope and largish foot print. A Con core would have even worse efficiency.

I am not saying all the devs are going to go hog wild. But FEAR wouldn't have died so quickly and while in the end the Android decision of Alien:Isolation made sense for the game, they chose the plodding simple Androids because just about every spare CPU resource to the Alien for the consoles. If they had more CPU resources we might have had more competent non-Aliens and even smarter Aliens. Like I said it's a lost art, sure the CoD's, FarCry's and the like of the world aren't going to take the extra time for it. But there are developers that would like to stretch their legs.

 

[Topweasel]

Do you really think that the 16 core on AM4 wont have a gamer mode?
(the setup is very similar like threadripper now)

Gamer mode as far as AM4 is only good for turning of SMT. Otherwise its useless. ThreadRipper now has 2-4 dies, with 2 of them driving 4 channels of memory, where interconnectivity and not latency was the first priority.

The new chiplets have no memory controllers. The IO die has them and the two chiplets are basically slaves to that. So all the Numa stuff that can both games on TR, shouldn't be an issue with the new chips. I wonder what latency will be like but either way even if the AM4 chip has 2 chiplets I seriously doubt that it will act like TR and that there is any benefit to the other Game mode functions.

 

[DrMrLordX]

There will probably be some core->core latency issues when trying to hop a thread between chiplets (or write data between threads handled by different chiplets). It would make more sense to help MS with their scheduler than try to shut down an entire chiplet to prevent such a thing from happening. That or just downclock one chiplet to let the scheduler not select it for high-priority threads.

 

[Tup3x]

So do we have a 16 core threadripper with only 2 memory channels used both on 1 die, to compare?

The situation with these is completely different than on previous Ryzens. It's a completely different design.

In fact, Threadripper should probably become viable gaming platform too.

 

[maddie]

It's a fight between many factors including power usage and price. Keep in mind that when these were being developed originally the only legitimate option without requiring AMD or Intel or IBM to start from scratch was what IvyBridge? It would have been 4 cores with a high power envelope and largish foot print. A Con core would have even worse efficiency.

I am not saying all the devs are going to go hog wild. But FEAR wouldn't have died so quickly and while in the end the Android decision of Alien:Isolation made sense for the game, they chose the plodding simple Androids because just about every spare CPU resource to the Alien for the consoles. If they had more CPU resources we might have had more competent non-Aliens and even smarter Aliens. Like I said it's a lost art, sure the CoD's, FarCry's and the like of the world aren't going to take the extra time for it. But there are developers that would like to stretch their legs.

Yep, time to have really challenging worlds. Just pushing the pretty things are becoming so boring.I don't only want things to look real, but behave real and smarter.

 

[Gt403cyl]

OK someone please explain to me why we need a 12 or 16 core CPU for gaming? Why not get a higher clocked 6 or 8 instead?

I would think a 12 core would be a benefit to people who stream their gameplay to places like Twitch/YouTube and don’t want/can’t afford to have a second machine.

There are lots of tasks where more cores/threads are a benefit, just as there are many that don’t benefit.

The thing is, you buy what will do the task(s) best, nothing wrong with having options.

 

[Kedas]

We have nothing to compare, since Ryzen 3000 series uses an IO die and a core die(s). We will find out then they come out.

The design is obviously changed and we won't have the right results until they release the CPU's but a 2 channel 16 core threadripper does have a very important common property, they both have 2 times 8 cores on a separate die with their own local cashe.
I don't think that the DDR4 part being present on one part of the dies or separate like Ryzen 3000 will have that much influence since this part is slow anyway.

The best would be that their IF is improved so much that the latency to the other die is not a big issue. It's likely that the core dies are connected directly also. (just like threadripper 16 core now)
or reduce the chances somehow that data from the other die will be needed.