AMD: Zen 3 Announced [2020-10-08]

Mr. Fritz: got the first shot (as usual), but not quite flawlessly:



It looks like the place for what would have been used to double the L3 interface logic and bandwidth have been "appropriated" for additional write buffers (the bright strips running vertically).

The IO die is the same with the one in Ryzen 3000 series.

 

8 cores is definitely more future proof, as the consoles will last till at least mid 2020s so the baseline for PC will slowly shift towards 8 cores. However, given the sheer number of systems still on 4 cores, and the large number of 6 core 3600/5600 series chips (not to mention 4-6 core laptop CPUs which are a significant part of the PC market today) which will be in systems, I'd expect that even 6 cores will hold up for at least 3 more years.

I agree on the value proposition though, AMD's pricing is pushing users towards a 5900X. A future 5700X @ $379 ($50 more than the 3700X) and a 5600 @ $229 should somewhat balance the lineup. AMD's flat $50 increase for Zen 3 is fine for the higher end parts as it's only 5-10% more. For the lower end parts, it's 20-25%, which is a bit much.

AMD themselves confirmed the IO die is the same so no surprises there, and it does make sense given that it's the same chipset/socket. I'm looking forward to them finally shrinking the IOD and potentially gaining even more power efficiency as I believe the IOD consumes ~20W. Rumour is a 6nm IOD for Zen 4, which could reduce that in half maybe?

 

Assuming Zen 4 IOD will support DDR5 and PCIe5 (like would be expected if it's on new socket), I wouldn't bet on consumption going much down at all even if the process does shrink. And one has to remember IOD is the one filled with PHYs which don't really scale that well on smaller processes.

 

DDR5 is confirmed but I suspect the consumer parts will not support PCIe5. We're barely seeing the benefit of PCIE 4.0 outside of high end SSDs and GPUs (a few %). USB4 is also possible but overall I don't see anything contributing significantly to power. Yes valid points but the current process is a derivative of a 2016 process. PHYs don't scale well on area but do they scale on power? A modern 2021 process could certainly have substantial gains in power. The gains will also be seen on the chipset as the current X570 at least is not very power efficient.

 

8GT/s PCIe3 uses about 5pJ/bit transferred
16GT/s PCIe4 uses about 7.5pJ/bit transferred.
32GT/s PCIe5 is expected to land around 11.5pJ/bit transferred.

PCIe4 uses 50% more energy per bit transferred and transfers twice the amount of bits per lane, tripling per lane power consumption.

PCIe5 is going to triple the power consumption again, and without a real need for the extra bandwidth we won't see it for some time, IMO.

Cheers

 

So I'd been planning on going for the 8 core & maybe pushing for 12 but prices & the performance of it is looking like 5600X is going to be the way to go for me.

I'm thinking save a bit on CPU, spend it on better RAM.
Is DDR4 4000 actually a thing? Fastest available at the store I'm likely to buy from is previously mentioned 3600 G.SKILL Trident Z Neo with 16-19-19-39 timing.
Is 2*16GB or 4*8GB the way to go?

Fairly budget so B550 mobo.

Its then occurred to me I need to take cooler into consideration, was pretty much assuming I can just use my existing cooler but I'm wondering about the validity of that assumption now?
My existing cooler has kept my i5 6600K stable at 4.3Ghz, no idea what voltage or temps but the fins get barely warm & the fan is nearly inaudible so I'm presuming its got ample cooling ability, I'm not going to have any bracket/clearance issues on AM4 am I?
I think I actually bought this thing for my old AM3 Thuban.

Edit: seems to be a Zalman cnps10x Quiet

 

For best performance you want 4 ranks of memory installed. There's been a lot of drama on YouTube recently on this topic. Zen 2 processors and Intel's current line-up are similarly sensitive.

https://www.techspot.com/article/1971-more-ram-modules-better-for-gaming/



I personally would always favour quantity of RAM over speed - it's how you make a build last 5 years+. I built my current system with 16GB in 2012, and it's been very smooth sailing... I suggest you contemplate 32GB.

Memory speed is barely relevant for 1440p or higher gaming.

5600X comes with a CPU cooler

 

WTH?? I had no idea having 4 sticks makes such a big difference. Now I'm even more p*ssed off that one of my RAM slots on my X570 is faulty! I've wanted to upgrade from 16GB to 32GB and consoled myself that I could at least swap out my current 2 8GB sticks for 2 16GB sticks. Now I find I'll actually be losing a ton of potential performance in doing so wonder if it's to late to send it back on warranty.

 

16GB sticks are often dual rank. This means 2 of them will give you 4 ranks, the same performance as 4 single rank sticks.

What's worse is that it's really hard to discern the count of ranks on a stick of RAM.

But, watch the video I linked, you'll see the performance differences are really not worth sweating over in GPU limited scenarios.

 

Well I pulled the trigger last night: 5600X, 2* 16GB 3600 RAM & B550 mobo.

Went for a bit less pricy CL18.
Had a bit of a fright, nearly bought a mobo with only 4* SATA ports, need 6* -> next 3 I looked at were also only 4* before I found other models with 6*
There's some interesting trade-offs in terms of what gets disabled/by populating which port/slot with the somewhat limited IO on B550 so gotta be a bit careful which to go with.

A week eta on delivery which is gonna seem to take forever

 

I managed to squeeze a bit more out of the 5800X with the latest BIOS on the X570 Tomahawk.



I'm leaving the CPU on auto clocks and applying a negative 25 curve offset in the advanced AMD overclocking settings plus 4x8GB 3800CL16 memory with tight sub-timings. This is considerably faster than my previous best results with the 3800X

 

So much for ETA, stuff arrived this morning

 

Up & running
No go on re-using my old cooler maybe if I can find an appropriate bracket somewhere...
But its not exactly sluggish with the tiny little cooler that came with it.
Seems to be running DDR 3600 no problem.
I have a bunch of tidy up to do to get my spinny drives up, wound up pulling them out of the case to get the mobo in, it was a bit tight before & this mobo is a bit wider.

 

Enjoy! It's always exciting getting new components.

 

Yep, all pretty solid stable & quick.
I've had to remove/re-do a lot of it too many times already for various fixes, putting in/out new DoA 8TB drive, rejigging cables/PCIE Sata card, switching in my old cooler fan instead of one of my noisy 1-pin case fans...

Now I've ordered a nice new cooler & couple more 3-pin fans with Black Friday sale so I'm gonna have to re-do the whole shebang pretty much when it all arrives but I should get better sustained clocks & much quieter case (I dunno why I never bothered to get some proper case fans, better ones are super-cheap & the one I've experimented with significantly quieter ), can then start trying to see if I can get in some OC.

 

So I went ahead today and ordered:

Asus Rog Crosshair VIII Hero X570
AMD 5800X
4x8GB RAM CL16 3600MHz
1TB Samsung 980 Pro
Fractal Define 7 Dark Tempered Glass Chassis
Fractal S36 Liquid CPU cooler
Coolermaster V1000 PSU

 

Curious choice, pretty much everyone agrees 5800X makes the least sense of them all with 5900X being so close in price and offers second CCD which brings additional benefits, too, and 5600X being pretty much equal in gaming.

 

Are they? the 5900x in my country is 125€ more expensive than the 5800X. I think the 5800X may not be the sweespot in value but I think is the best choice if you don't want to break the bank and have a CPU that will last until the mid of the decade (if not more).

 

We have it 100€ more expensive in Finland.
But let's assume your 5800X is around the same price as here, so around 475€, 5900X 125€ more would be 600€. That's about 25% more money for 50% more cores, double the cache and higher boost clocks, for us it's a bit less but even for your difference I think it's a no-brainer

 

Local prices 5600X $518, big step up to $763 for 5800X then a smaller bump to $939 for the 5900X but its pushing close to twice the price of the 5600X.