7800X3D, 7900X3D, 7950X3D..

[EightyDuce]

2 hours ago, blkspade said:

I feel that the 12-16 core models are a bigger deal because there are a lot of mixed use people on Zen 3 R9s that have been screaming for a v cache option. I'm on a 5950X and always have at least one virtual machine running and if I'm booted to Linux then Windows itself is going to be a VM. Other things I do in bursts benefit from having all those threads. It's a weird position to be in where I'll frequently use and appreciate the all the threads, but also play games where a 5800X3D crushes. Something like star citizen can go from mildly sub-par to really good. For people absolutely good with 8 cores the 5800X3D and 7700X are really good and fairly close most of the time. For me personally it would be great to have the combination of an iGPU, 32 threads, and vcache with the ability isolate a whole OS to a specific CCD.

Since they announced that 79X0X3D would hit before 7800X3D, I've been kicking aorund the idea of getting a 7950X3D. For the most part I have no need for this many cores/threads (I did couple of years ago when I encoded my entire movie library, that was a chit show). But I'm starting to rationalize to myself that it may be a good idea to have best of both worlds; a vcache CCD for most games that take advantage of it and a high clocking non Vcache CCD for games that don't. 

My only concern, one that has been echoed by many, is the potential hardware scheduler issues which we won't know is valid or not until reviews hit. 

[Hoirtel]

1 hour ago, EightyDuce said:

Since they announced that 79X0X3D would hit before 7800X3D, I've been kicking aorund the idea of getting a 7950X3D. For the most part I have no need for this many cores/threads (I did couple of years ago when I encoded my entire movie library, that was a chit show). But I'm starting to rationalize to myself that it may be a good idea to have best of both worlds; a vcache CCD for most games that take advantage of it and a high clocking non Vcache CCD for games that don't. 

My only concern, one that has been echoed by many, is the potential hardware scheduler issues which we won't know is valid or not until reviews hit. 

We are in the same position. I actually do PC productivity work but my current PC was still going to perform this task, the new machine was going to be DCS only. 

Also not sure about the scheduler and I guess we wouldn't know how this works for DCS specifically until someone tries it... 

[SkateZilla]

9 hours ago, EightyDuce said:

Cache isn't allocated per core. All cores on the CCD have access to the same pool of cache. 

As for thermals, if there is any difference, it would be negligible (couple of degrees). The reason they down-clocked (less power, less heat) the vcache CCD is to stay within the thermal envelope that allows non cache CCD to hit higher speeds. 

Well the L3 Cache is Tricky, in the past it was per core, as all the cores were on the same die, and the L3 was adjoined to the Cores, so a laser cut core, would also cut the L3.

With Zen, it's per CCX, as the Cache is centrally located on the CCX Between the cores, but any core on the CCX can access the L3 Pool.

So if they Stack the Extra say 64MB on the VCache on one CCX, and there's 
7950X is 16 Cores and 64MB of Cache / 2 CCXs =  32 MB L3 Per CCX. (64 MB Total).

So:
The 7950X3D is basically the Full 16 Cores x 2 CCX x 32 MB + the 64MB of VCACHE = 128MB L3
The 7900X3D is basically the cut 12 Cores x 2 CCX x 32 MB + the 64MB of VCACHE = 128MB L3
The 7800X3D is basically the 8 Cores x 1 CCX x 32 MB + the 64MB of VCACHE = 96MB L3

And you can look at any CCX's that fail 3 Cores can be cut to 4 as well, 
So you can have 2 SubRevisions of 7900X3D, Depending on Defects in the yields.
One with 8 Full Cores on a CCX, and 4 on the other, the 32 MB of L3 Per CCX Remains accessible + the additional 64MB of L3 VCACHE.
One with 6 Full Cores on a CCX, and 6 on the other, the 32 MB of L3 Per CCX Remains accessible + the additional 64MB of L3 VCACHE.

The Performance would be limited to thermals on the CCX without the VCache Stacked on it.

 

 

What confuses users now is AMD's Site lists 7950 and 7900X3D as 128MB L3., and the 7800X3D as 96.
While the slide published shows, 104MB ,140MB , 144MB of L3 Cache, So where's the additional 8/12/16 MB of L3 Coming from...?
 

Edited February 5, 2023 by SkateZilla

[BitMaster]

L2 Cache maybe ?

 

Edited February 5, 2023 by BitMaster

[SkateZilla]

1 hour ago, BitMaster said:

L2 Cache maybe ?

 

 

Yup, Didnt realize the slide simply said "Cache" didnt specify L2 or L3, But 7950X35 is 16MB L2, 7900X3D is 12, and 7800X3D is 8

[derneuemann]

Am 2.2.2023 um 14:54 schrieb Rix:

Somewhat agree - although 10-15% is the gray zone for a decision.  Looks like we're getting close to multicore/Vulcan, and based on that it would be wise to let it all play out.  Aero users are always chasing hardware.  The battle is not frames - getting solid > 60fps, and staying between 12-15ms, but stuttering.

 

I think so too, except that my gray area would start at 15-25% at the earliest, if at all.

What are we talking about in VR that a CPU delivers frame times of maybe 15ms and the GPU another 10 - 30 depending on the headset and settings.

What's the use of 10-15% more CPU performance... A saving of 1.5-2ms. That would be just 3 fps more in my example.

There are certainly moments when a CPU is at 25ms in the worst case. Even here it would only be 3 fps more.

If you really want to get the maximum out now, you should use a 13600k with Peltier element and Waku and run it at 6.2GHz, with DDR5 7200. I don't think a 7800X3D will top that either. Unfortunately it doesn't really do anything.

The only ones that really "can" help (if ED tries hard) are MT and Vulcan.

[Hoirtel]

So looking at motherboard prices I think that a B650E that has PBO should be plenty for even a 7950X3D. I do quite like gigabyte boards but thinking maybe a Strix B650E-F this time. Can't see why a X670 is necessary...

[Hoirtel]

First glimpse. Salt required.... but looking good. Only last few minutes are related to X3D. 

[Hoirtel]

So very quiet on the news about these chips considering they come out next week. I am agonising about RAM to buy, have to wait for tests. Seems AM5 is very picky but I bet that the vcache will not be as bad. Do I get that decent 32gb or a slower hynix 64gb kit. Hmmmm. 

[AngleOff66]

B650 board review

WTH is ASUS doing?

Edited February 22, 2023 by AngleOff66

[LucShep]

On 2/22/2023 at 3:28 PM, Hoirtel said:

So very quiet on the news about these chips considering they come out next week. I am agonising about RAM to buy, have to wait for tests. Seems AM5 is very picky but I bet that the vcache will not be as bad. Do I get that decent 32gb or a slower hynix 64gb kit. Hmmmm. 

No idea where you're located, but you may have Amazon able to ship to your country. If not, search around in online or physical PC hardware stores in your location.

Good 64GB RAM kits for AM5, I suggest searching for either of these two:

• GSKILL F5-6000J3238G32GX2-TZ5N  (DDR5-6000 CL32-38-38-96 1.40V) - https://www.gskill.com/product/165/393/1665020484/F5-6000J3238G32GX2-TZ5N
• GSKILL F5-6000J3238G32GX2-TZ5NR  (DDR5-6000 CL32-38-38-96 1.40V) - https://www.gskill.com/product/165/390/1665020956/F5-6000J3238G32GX2-TZ5NR

If those are not available anywhere, then yeah, you may have to locate alternatives, likely to be ones with slower speed and/or timings.

If you have to decide between slightly slower 64GB or fast 32GB, then IMO I'd go for the former (more capacity), as speed/latency can't help you once the RAM capacity limits are reached in-game (applies to online busy servers mostly, which can and will take over 32GB of RAM).

Edited February 25, 2023 by LucShep

[Hoirtel]

2 hours ago, LucShep said:

No idea where you're located, but you may have Amazon able to ship to your country. If not, search around in online or physical PC hardware stores in your location.

Good 64GB RAM kits for AM5, I suggest searching for either of these two:

• GSKILL F5-6000J3238G32GX2-TZ5N  (DDR5-6000 CL32-38-38-96 1.40V) - https://www.gskill.com/product/165/393/1665020484/F5-6000J3238G32GX2-TZ5N
• GSKILL F5-6000J3238G32GX2-TZ5NR  (DDR5-6000 CL32-38-38-96 1.40V) - https://www.gskill.com/product/165/390/1665020956/F5-6000J3238G32GX2-TZ5NR

If those are not available anywhere, then yeah, you may have to locate alternatives, likely to be ones with slower speed and/or timings.

If you have to decide between slightly slower 64GB or fast 32GB, then IMO I'd go for the former (more capacity), as speed/latency can't help you once the RAM capacity limits are reached in-game (applies to online busy servers mostly, which can and will take over 32GB of RAM).

 

Yeah all I can see is 64GB cl40. However I recently got 64 for my current system (DRR4) and everytime I check it's not over 29gb used... That was also on grayflag. I really do need to see if I can record ram use as I am not convinced I need 64...

[skypickle]

On 2/5/2023 at 8:34 PM, SkateZilla said:

Yup, Didnt realize the slide simply said "Cache" didnt specify L2 or L3, But 7950X35 is 16MB L2, 7900X3D is 12, and 7800X3D is 8

i assume this is total L2 so the per core L2 is the same across all chips?

[SkateZilla]

54 minutes ago, skypickle said:

i assume this is total L2 so the per core L2 is the same across all chips?

The Slide shows L2 + L3 cache.

[EightyDuce]

Some 7950X3D leakage. 

https://www.hd-tecnologia.com/segun-amd-el-ryzen-9-7950x3d-es-6-mas-rapido-que-el-i9-13900k-y-16-mas-rapido-que-el-ryzen-9-7950x-en-juegos/

 

Looks like about 6% better than  13900K (not KS) and 16% better than 7950X. 

Take with some salt, but appears to be a leaked AMD review guide. 

[BitMaster]

My son said he needs a new PC....so if the monkey bites me I'll end up with one of those 9er X3D's and hand my rig down to my eldest one, take his 7700k in return for the younger ones and call it a day. Yeah, there is the need for a GPU as well...will see.

Thing is, I really LOVE this 5900X Build, it's the most reliable machine I have built in more than 1 decade, maybe ever. Not a single BSOD or glitch ever, hands down. That keeps me more back than anything else. I remember 6700K disaster, 7700k was OK and still is, my 8700k never liked fast RAM but loved BSOD's, etc etc...  and this 5900X just works.   and I say this as someone who fixes and builds rigs, this is one of a kind.

Edited February 24, 2023 by BitMaster

[some1]

4 hours ago, EightyDuce said:

Looks like about 6% better than  13900K (not KS)

Looks like a repeat of the situation with 5800X3D, which means calculating average from a set of games is the least useful thing to do. 

In games that make heavy use of cache, which often includes open world and simulator games, they show up to 25-30% improvement. That is more than a generational jump between CPUs. 

In games that favor raw clock speed the X3D shows worse results, but these are often lighter, online oriented games which run at couple hundreds FPS anyway. 

[BitMaster]

Indeed, it will be very interesting to see how they perform across a variety of games and apps and how the single CCD 7800X3D performs and how much better the 2x CCD variants 79xxX3D perform.

Will DCS prefer the Cache heavy CCD or will it use both for the coming new threads, who knows. Just if some of those threads really like fast cores more than Cache it will show once

multi threading arrives which may happen this year ( fingers crossed ). I just know, for 100€ more I would grab the 16 core CPU this time and load it with 128GB if those kits are available then.

[Hoirtel]

15 hours ago, BitMaster said:

Indeed, it will be very interesting to see how they perform across a variety of games and apps and how the single CCD 7800X3D performs and how much better the 2x CCD variants 79xxX3D perform.

Will DCS prefer the Cache heavy CCD or will it use both for the coming new threads, who knows. Just if some of those threads really like fast cores more than Cache it will show once

multi threading arrives which may happen this year ( fingers crossed ). I just know, for 100€ more I would grab the 16 core CPU this time and load it with 128GB if those kits are available then.

I can't see multithreading making a huge difference to the requirements. The last announcement said the first implementation would use two threads. I think the 7800X3D will be the one to go for for just DCS, and the 7950X3D for DCS and any productivity/creativity work. If a multi threaded DCS was to use one thread on each CCD there would likely be problems with latency.

Would DCS really use 128Gb RAM? I can't get my system to use over 32... 128 would come with some perf penalties too. 

Edited February 25, 2023 by Hoirtel

[SkateZilla]

https://www.techpowerup.com/305181/amds-reviewers-guide-for-the-ryzen-9-7950x3d-leaks

[skypickle]

Benchmarks looking at the 5800x3d showed massive gains in msfs and dcs over non x3d parts and were on par with a 13900k. Too bad very few reviewers look at flight sims

[BitMaster]

vor 10 Stunden schrieb Hoirtel:

I can't see multithreading making a huge difference to the requirements. The last announcement said the first implementation would use two threads. I think the 7800X3D will be the one to go for for just DCS, and the 7950X3D for DCS and any productivity/creativity work. If a multi threaded DCS was to use one thread on each CCD there would likely be problems with latency.

Would DCS really use 128Gb RAM? I can't get my system to use over 32... 128 would come with some perf penalties too. 

 

Oh, 64GB is for DCS, I can use 128GB in virtual machines, not for DCS (yet).

I had my DCS way over 40GB, almost 50GB usage,  MP, heavy mission, big preload and highisch LOD

[ironhard]

 

[EightyDuce]

Waiting on VR reviews especially DCS specific but right now it kind of looks like I may be staying with the 7700x.

 

 

 

Edited February 27, 2023 by EightyDuce

[some1]

If MSFS is any indicator, it's good:

https://www.tomshardware.com/reviews/amd-ryzen-9-7950x3d-cpu-review/6

Also here: 

https://www.eurogamer.net/digitalfoundry-2023-amd-ryzen-9-7950x3d-review?page=2

But the 7800X3D that is coming in 2 months should be just as fast in these applications, and much cheaper. 

Edited February 27, 2023 by some1