AMD Ryzen 7 5800X3D vs AMD Ryzen 7 5800X: A Cache Value?

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Disappointed with the MS2020 gains. Yes 9% in 4K or similar in VR I suppose. Clock a non 3D chip up and we have diminishing returns with the 3D. If the price was the same then hell ya. But right now based on those well made graphs nope.
 

noko

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I've notice huge uptakes for minimum FPS in FarCry 6 where it really counts and is noticeable at even 4K resolution. Just a huge difference comparing a 3900x to a 5800x3d. I also have a 5800x in another machine but did not make any comparisons there. I would not even bother that much with averages, it is the lows even momentarily, those jerky to sutter periods that makes the 5800x3d really pop out over other CPUs.
 

noko

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This review is one of the reasons I am pissed at AMD for shafting us TRX40 users and refusing to give us a Zen3 version.

I hate compromises. I want a build that gives me everything a HEDT system offers (primarily ECC, high PCIe lane counts and IOMMU, but high core counts don't hurt either) without sacrificing top of the line game performance.

I hate compromises. They drive me nuts.
Same boat on one machine with a 3090 being held back by the Zen 2 cores particularly the minimum FPS. I will probably move the 5800x3d rig into the computer room with VR (Flight Simulator is awesome in VR being limited severely by the 3960x). Some rumor that AMD may support DDR4 with Zen 4, lol, hopefully that will be with TRX40 as well.
 

Peter_Brosdahl

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it is the lows even momentarily, those jerky to sutter periods that makes the 5800x3d really pop out over other CPUs.
That was one of the things I noticed when I upgraded from my 3700x to it. Frames are just so smooth now. There are some still occasional jitters but I can usually attribute them to something loading in. Otherwise, it's really impressive. I recently was lucky enough to use EVGA step-up to get a 3090 Ti and between that and the C2 (G-Sync) everything is so happy with each other. I haven't tried the latest Flight Sim but I'm sure it'd look great.
 

Zarathustra

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it is the lows even momentarily, those jerky to sutter periods that makes the 5800x3d really pop out over other CPUs.
That was one of the things I noticed when I upgraded from my 3700x to it. Frames are just so smooth now. There are some still occasional jitters but I can usually attribute them to something loading in. Otherwise, it's really impressive. I recently was lucky enough to use EVGA step-up to get a 3090 Ti and between that and the C2 (G-Sync) everything is so happy with each other. I haven't tried the latest Flight Sim but I'm sure it'd look great.

That makes perfect sense. These are probably moments where another CPU would be pulling data from RAM, but because the cache on this thing is so large it can just retrieve the data there instead, much more quickly.
 
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Peter_Brosdahl

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That makes perfect sense. These are probably moments where another CPU would be pulling data from RAM, but because the cage on this thing is so large it can just retrieve the data there instead, much more quickly.
I started to theorize about similar performance gains years ago when I got my 4930K. It was my first processor to go beyond 4C/8T but at the time most things were still not optimized for more threads and even though, at the time, I wasn't overclocking it and it was running at slower clock speeds (3.4 GHz boost to 4.2 GHz) I noticed significantly improved performance over the 2600K (OC'd to 4.2 GHz). Both systems had nearly identical ram and other specs back then. The 1st thing I started to attribute it to was the increased cache. I knew there were other factors like instruction sets and other CPU-specific items but that was something that really stood out. It was about a year later that someone gave me some great tips for OCing the 4930K to 4.3 GHz and that thing has been a champ ever since. It's still chugging away in the cave.
 

Zarathustra

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I started to theorize about similar performance gains years ago when I got my 4930K. It was my first processor to go beyond 4C/8T but at the time most things were still not optimized for more threads and even though, at the time, I wasn't overclocking it and it was running at slower clock speeds (3.4 GHz boost to 4.2 GHz) I noticed significantly improved performance over the 2600K (OC'd to 4.2 GHz). Both systems had nearly identical ram and other specs back then. The 1st thing I started to attribute it to was the increased cache. I knew there were other factors like instruction sets and other CPU-specific items but that was something that really stood out. It was about a year later that someone gave me some great tips for OCing the 4930K to 4.3 GHz and that thing has been a champ ever since. It's still chugging away in the cave.



I'm wondering if I see some of those benefits on the Threadripper. It has a pretty large amount of ache as well, but I am not sure how the cores share it.

As a comparison:

L1L2L3
Ryzen 7 5800X32KB inst + 32KB data per core = 512KB512KB per core = 4MB32MB
Ryzen 7 5800X3D32KB inst + 32KB data per core = 512KB512KB per core = 4MB96MB
my Threadripper 3960x32KB inst + 32KB data per core = 1.5MB512KB per core = 12MB128MB

I suspect the L1 and L2 are the same, and are per core, but are just larger on my Threadripper due tot he larger number of cores. I think the real benefit comes in the L3 as I think any one core can benefit from all of it.
 

Brian_B

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I'm wondering if I see some of those benefits on the Threadripper
From "that other thread"

Another big benefit on the 5800 is that there is only 1 CCD - nothing has to jump across infinity fabric. If you lock your TR to just the cores on a single CCD you might get at that.
 

Zarathustra

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From "that other thread"

Another big benefit on the 5800 is that there is only 1 CCD - nothing has to jump across infinity fabric. If you lock your TR to just the cores on a single CCD you might get at that.

That is true, but I vaguely remember this being worse in the Threadripper 1xxx and 2xxx models. There was something about the newer ones that mitigated (at least partially) the infinity fabric penalty.

I cant remember the details though.
 

Brian_B

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That is true, but I vaguely remember this being worse in the Threadripper 1xxx and 2xxx models. There was something about the newer ones that mitigated (at least partially) the infinity fabric penalty.
Yeah, but avoiding the problem all together is a heck of a lot better than any mitigation.

The third gen had the separate I/O chiplet along with improved infinity fabric design, although I'll be darned if I can find any info on it with a cursory search. I'd have to dig deeper, but yeah, I remember what you are recalling as well.
 
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