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AMD EPYC “Rome” Server Processors to Feature 8 to 64 Cores

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Re: AMD EPYC “Rome” Server Processors to Feature 8 to 64 Cores

#41

Post by ip26 »

kllrnohj wrote: post #32
nabla9 wrote: post #15

Does anyone have an idea how many different processors tapeouts are needed to create this line? It seems reasonable to assume that 48-core chip is just 64-core chip with few defective cores. A lower clocked version is the same ship that high clocked that did not pass some test.

There's 9 different independent pieces of silicon on the 64-core chip. It looks like this: https://images.anandtech.com/doci/13561/amd_rome-678_678x452... ( source https://www.anandtech.com/show/13561/amd-previews-epyc-rome-... ) Each of those smaller dies is 8 cpu cores. So 8x8 = 64. The 48-core one could either be 6 full-yield chiplets, or 8 partially defective ones with just 6 cores active. I'd guess it's 8 chiple…

It depends on yield. If it's very high, you save money using only 6 chiplets. If it's not as great then using 8 lets you downbin the 64 core parts that were defective into the 48 core slot.

You can't do both in the same SKU because they have different performance, e.g. different amounts of L3 cache & memory bandwidth.

Re: AMD EPYC “Rome” Server Processors to Feature 8 to 64 Cores

#42

Post by ip26 »

djsumdog wrote: post #21

Do these processors use NUMA, similar to the high end Intel Xeon chips?

NUMA isn't a feature, it's a design compromise. Ideally every line of memory takes the same amount of time to access. But in large complex designs, you can increase performance for some memory at the price of lower performance for other memory, aka Non Uniform Memory Access.

(These chips do exhibit NUMA)

Re: AMD EPYC “Rome” Server Processors to Feature 8 to 64 Cores

#44

Post by Ragib_Zaman »

mtgx wrote: post #6
abc_lisper wrote: post #2

Giddy! At this rate I will be running a 64 Core processor on my desktop in 2 years!

There's already a 64-core Threadripper rumored for the end of this year. Top-tier Ryzen 9 should reach "only" 32 cores on the 5nm process in 2 years.

Is this conjecture or has AMD stated in a roadmap they plan to have 5nm in 2 years?

Re: AMD EPYC “Rome” Server Processors to Feature 8 to 64 Cores

#45

Post by kllrnohj »

shereadsthenews wrote: post #35
kllrnohj wrote: post #29

Earlier quoted context omitted.

Rome is Zen 2. You have absolutely no clue whatsoever how it performs. It may still have the weaknesses of Zen 1, but it very well might not. AMD made a bunch of changes, including a complete overhaul of the memory system (no more NUMA). We'll know for sure when the product is actually out and we have independent benchmarks, but at this point you're just making things up and stating them as facts. That aside Epyc was…

Don’t assume everyone suffers from the same ignorance that you suffer. All buyers in a position to order large quantities of CPUs have Rome samples and have had them for a long time, yet Intel price doesn’t budge. Why?

Don’t assume everyone suffers from the same ignorance that you suffer. The buyers in a position to get early samples of Rome are not paying retail prices on Intel.

And those players have already announced AMD is being added to their offerings: https://aws.amazon.com/ec2/amd/

Re: AMD EPYC “Rome” Server Processors to Feature 8 to 64 Cores

#46

Post by ufoolme »

stcredzero wrote: post #37
uponcoffee wrote: post #18

Earlier quoted context omitted.

There's probably bit of hardware lot it with Intel chips. Since they control the hardware, Apple probably has invested quite a bit into hardware specific optimizations that won't readily port to AMD chipsets. Also, AMD is only recently been a performance front runner - they might not hold on to that for long. In the short term it doesn't make sense to jump ship. For for general computation/ecosystems or for generatio…

Since they control the hardware, Apple probably has invested quite a bit into hardware specific optimizations that won't readily port to AMD chipsets. It's in Apple's history to be able to move on from hardware. It's also in their history to make the wrong choices, necessitating the move.

money is they’ll move in next 5 years to at least partial move to their own ARM chips, they already have to a degree.

Re: AMD EPYC “Rome” Server Processors to Feature 8 to 64 Cores

#47

Post by Rebelgecko »

mfatica wrote: post #31
MuffinFlavored wrote: post #10

Earlier quoted context omitted.

and still have some I/O operation block your entire GUI/OS :D

elaborate?

I think they're pointing out that many of the bottlenecks that make computers feel slow can't be fixed by throwing more cores at them—multithreading can be tricky

Re: AMD EPYC “Rome” Server Processors to Feature 8 to 64 Cores

#49

Post by eightysixfour »

ip26 wrote: post #42
djsumdog wrote: post #21

Do these processors use NUMA, similar to the high end Intel Xeon chips?

NUMA isn't a feature, it's a design compromise. Ideally every line of memory takes the same amount of time to access. But in large complex designs, you can increase performance for some memory at the price of lower performance for other memory, aka Non Uniform Memory Access. (These chips do exhibit NUMA)

I believe these chips have Uniform Memory Access via a shared memory interface on the I/O die. Am I mistaken?

Edit, just confirmed:

>Thanks to this improved design, each chiplet can access the memory with equal latency. The multi-core beasts can support to 4TB of DDR4 memory per socket.

https://www.tomshardware.com/news/amd-64-core-128-thread-7nm...

Re: AMD EPYC “Rome” Server Processors to Feature 8 to 64 Cores

#50

Post by astrodust »

33degrees wrote: post #22
rubyn00bie wrote: post #5

The real question for me with all these AMD releases, what's Intel gonna release? It's surprising to me that Apple didn't announce an AMD based Mac Pro-- the chip Intel gave them must really be something. Too bad though because there could be a lot more of them (eventual Mac Pros) out there I'm guessing if they were using these Rome chips.

At this point, I think it's a lot more likely for Apple to switch to using their own chips, at least at the low end.

Given the JavaScript performance of the shipping units intended for mobile use, which is eclipsing the best of Intel's offerings, it might be possible that the A14 or A15 iteration actually surpasses Intel's chips at x86-64 code as well when run through a Rosetta-like compatibility layer.

What if the high-end chip was ARM? It's not just about raw speed, it's about how much performance you can squeeze out of a particular thermal envelope, or compute per watt. If ARM offers 2x the performance per watt, doesn't matter what Intel's chips do with hypothetically unlimited power.

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