Personal computing discussed

Moderators: Flying Fox, morphine

 
Kougar
Silver subscriber
Minister of Gerbil Affairs
Topic Author
Posts: 2031
Joined: Tue Dec 02, 2008 2:12 am
Location: Texas

No Dummy Dies on Threadripper?

Sat Sep 16, 2017 8:18 pm

So Der8auer has apparently taken issue with the circulated claim that Threadrippers are two die and two dummy placeholders. He not only delidded a second Threadripper, but popped the dies off it for good measure. https://www.youtube.com/watch?v=N-uKQ6RfUdk

After I got done crying over the wasted hardware he did have some cool photos of the die circuitry he's posted here: http://www.mediafire.com/file/7l8nyi1q43tm3ab/TRDie.zip

And, both of his TR chips had four Ryzen die on them.
 
Ummagumma
Gerbil
Posts: 26
Joined: Fri May 27, 2016 9:18 pm

Re: No Dummy Dies on Threadripper?

Sat Sep 16, 2017 9:04 pm

After looking at the pictures with my untrained eyes, I agree that the dies certainly appear to be "etched dies" that may or may not be "functional" (meaning: "they might work") and "may be" actual processor chips. To prove that each die truly is (or was) a functional processor chip, each die would have to be individually tested. Sadly I suspect the "delidding" process actually destroys the "viability" of the dies.

Additionally, simply proving the package had 4 dies that were actually "etched" does not prove to me that any given die was either "operational" (powered up & processing instructions) within the package, or just there and "non-operational" to spread out the load of the external heatsink-fan assembly within the package.

Therefore, I think the argument still exists that 1 or 2 dies in each package of 4 could still be a "QC failed" die. So as far as I am concerned, "the jury is still out on this matter".
I used to do networking & network security for a living. Now I just do it for fun, but I still take it seriously.
 
Waco
Gold subscriber
Minister of Gerbil Affairs
Posts: 2032
Joined: Tue Jan 20, 2009 4:14 pm
Location: Los Alamos, NM

Re: No Dummy Dies on Threadripper?

Sat Sep 16, 2017 11:02 pm

It does bring back the hope of a 32 core HEDT chip. :)
Z170A Gaming Pro Carbon | 6700K @ 4.5 | 16 GB | GTX Titan X | Seasonix Gold 850 | XSPC RX360 | Heatkiller R3 | D5 + RP-452X2 | Cosmos II | Samsung 4K 40" | 480 + 240 + LSI 9207-8i (128x8) SSDs
 
just brew it!
Gold subscriber
Administrator
Posts: 49696
Joined: Tue Aug 20, 2002 10:51 pm
Location: Somewhere, having a beer

Re: No Dummy Dies on Threadripper?

Sat Sep 16, 2017 11:06 pm

Waco wrote:
It does bring back the hope of a 32 core HEDT chip. :)

I see no technical reason why they couldn't do that, but you still wouldn't be able to run more than quad-channel RAM. Wouldn't Epyc make more sense if you want more capability than Threadripper provides?
Nostalgia isn't what it used to be.
 
the
Gold subscriber
Gerbil Elite
Posts: 851
Joined: Tue Jun 29, 2010 2:26 am

Re: No Dummy Dies on Threadripper?

Sun Sep 17, 2017 2:30 pm

Long term I see AMD going the interposer route for their entire line up once real mass production has started. The difference between TR and Epyc is of course the IO which AMD will through in an extra IO die for Epyc. The number of CPU cores is basically limited by the size of the interposer they can make or fit into that package. Alternatively, TR could simply be Epyc with a full compliment of IO dies but some disabled due to defects or bonding issues in this scenario.

Between interposers and Intel's EMIB, the market is primed for a massive increase in how much silicon is put into a socket. I've been meaning to put something together about this to help illustrate the idea of how each company could scale their designs (and nVidia too who has done a bit of saber rattling around this principle).
Dual Opteron 6376, 96 GB DDR3, Asus KGPE-D16, GTX 970
Mac Pro Dual Xeon E5645, 48 GB DDR3, GTX 770
Core i7 3930K@4.2 Ghz, 32 GB DDR3, GA-X79-UP5-Wifi
Core i7 2600K@4.4 Ghz, 16 GB DDR3, GTX 970, GA-X68XP-UD4
 
Waco
Gold subscriber
Minister of Gerbil Affairs
Posts: 2032
Joined: Tue Jan 20, 2009 4:14 pm
Location: Los Alamos, NM

Re: No Dummy Dies on Threadripper?

Mon Sep 18, 2017 8:14 am

just brew it! wrote:
Waco wrote:
It does bring back the hope of a 32 core HEDT chip. :)

I see no technical reason why they couldn't do that, but you still wouldn't be able to run more than quad-channel RAM. Wouldn't Epyc make more sense if you want more capability than Threadripper provides?

Absolutely, but many folks won't run a server board in a multipurpose build...even if the "desktop" version of the same board is identical under the hood.
Z170A Gaming Pro Carbon | 6700K @ 4.5 | 16 GB | GTX Titan X | Seasonix Gold 850 | XSPC RX360 | Heatkiller R3 | D5 + RP-452X2 | Cosmos II | Samsung 4K 40" | 480 + 240 + LSI 9207-8i (128x8) SSDs
 
chuckula
Gold subscriber
Gerbil Jedi
Posts: 1569
Joined: Wed Jan 23, 2008 9:18 pm
Location: Probably where I don't belong.

Re: No Dummy Dies on Threadripper?

Mon Sep 18, 2017 9:13 am

All the noise about Threadripper going to 32 cores because AMD put some non-functional dies in the dummy slots of the Threadripper package is amusing, although AMD basically lied to the press when they claimed that those dummy dies are blanks.

The funny part about it is all the breathless speculation that AMD can suddenly wave a wand and turn Threadripper into a 32 core product when it's actually substantially more difficult for AMD to pull off that feat from a technology perspective than it would be for Intel to simply take a 28-core Xeon die and drop it into the LGA-2066 package.
4770K @ 4.7 GHz; 32GB DDR3-2133; GTX-1080; 512GB 840 Pro (2x); Fractal Define XL-R2; NZXT Kraken-X60
--Many thanks to the TR Forum for advice in getting it built.
 
Waco
Gold subscriber
Minister of Gerbil Affairs
Posts: 2032
Joined: Tue Jan 20, 2009 4:14 pm
Location: Los Alamos, NM

Re: No Dummy Dies on Threadripper?

Mon Sep 18, 2017 9:18 am

chuckula wrote:
The funny part about it is all the breathless speculation that AMD can suddenly wave a wand and turn Threadripper into a 32 core product when it's actually substantially more difficult for AMD to pull off that feat from a technology perspective than it would be for Intel to simply take a 28-core Xeon die and drop it into the LGA-2066 package.


I think you're overstating the difficulty of enabling a few dies and understating the simplicity of dropping an entirely new Xeon onto a new (for it) socket/chipset ecosystem.

All AMD has to do is package and enable 2 extra dies. It would be best if they had a single memory channel each (total 4) but I could see them simply enabling the two extra dies and forcing them to run as remote NUMA domains from main memory. The former would take *maybe* some work, depending in implementation. The latter? It would be trivial.
Z170A Gaming Pro Carbon | 6700K @ 4.5 | 16 GB | GTX Titan X | Seasonix Gold 850 | XSPC RX360 | Heatkiller R3 | D5 + RP-452X2 | Cosmos II | Samsung 4K 40" | 480 + 240 + LSI 9207-8i (128x8) SSDs
 
chuckula
Gold subscriber
Gerbil Jedi
Posts: 1569
Joined: Wed Jan 23, 2008 9:18 pm
Location: Probably where I don't belong.

Re: No Dummy Dies on Threadripper?

Mon Sep 18, 2017 9:26 am

Waco wrote:
chuckula wrote:
The funny part about it is all the breathless speculation that AMD can suddenly wave a wand and turn Threadripper into a 32 core product when it's actually substantially more difficult for AMD to pull off that feat from a technology perspective than it would be for Intel to simply take a 28-core Xeon die and drop it into the LGA-2066 package.


I think you're overstating the difficulty of enabling a few dies and understating the simplicity of dropping an entirely new Xeon onto a new (for it) socket/chipset ecosystem.

All AMD has to do is package and enable 2 extra dies. It would be best if they had a single memory channel each (total 4) but I could see them simply enabling the two extra dies and forcing them to run as remote NUMA domains from main memory. The former would take *maybe* some work, depending in implementation. The latter? It would be trivial.


Uh, there's nothing trivial about cramming two extra functional dies into a platform that was intentionally designed to never hook up the two non-functional dies to anything whatsoever. Hooking up a 28-core Xeon to LGA-2066 basically means routing power to the correct pins and using exactly the same pinouts for memory & PCIe that are already shipping in products right now. It's not even in the same ballpark in the level of complexity and the potential performance trainwrecks you are heading for when you cripple the connections to those "32 core" threadrippers and try to do a real benchmark that's harder than Cinebench.

TL;DR version: If you want an Epyc server, buy one. Don't pretend that the cut-down Threadripper platform is magically designed to be equivalent to an Epyc platform, because it clearly isn't.
4770K @ 4.7 GHz; 32GB DDR3-2133; GTX-1080; 512GB 840 Pro (2x); Fractal Define XL-R2; NZXT Kraken-X60
--Many thanks to the TR Forum for advice in getting it built.
 
Waco
Gold subscriber
Minister of Gerbil Affairs
Posts: 2032
Joined: Tue Jan 20, 2009 4:14 pm
Location: Los Alamos, NM

Re: No Dummy Dies on Threadripper?

Mon Sep 18, 2017 1:11 pm

chuckula wrote:
TL;DR version: If you want an Epyc server, buy one. Don't pretend that the cut-down Threadripper platform is magically designed to be equivalent to an Epyc platform, because it clearly isn't.

I never claimed otherwise.

I claimed that enabling two dies on an interposer that already has inter-die connections is trivial if you're willing to take the tradeoff of remote memory access for those two extra dies.
Z170A Gaming Pro Carbon | 6700K @ 4.5 | 16 GB | GTX Titan X | Seasonix Gold 850 | XSPC RX360 | Heatkiller R3 | D5 + RP-452X2 | Cosmos II | Samsung 4K 40" | 480 + 240 + LSI 9207-8i (128x8) SSDs
 
Kougar
Silver subscriber
Minister of Gerbil Affairs
Topic Author
Posts: 2031
Joined: Tue Dec 02, 2008 2:12 am
Location: Texas

Re: No Dummy Dies on Threadripper?

Wed Sep 20, 2017 10:49 am

That's just it, why would AMD go through all the trouble and cost of creating a 4-die package in the first place if it didn't intend to make use of it later? It is doubling the cost of diffusing the chips since all four die/dice receive the same indium/gold plating and soldering to the IHS (and also wouldn't require the use of two non-functional die which could bite them later when yields improve).

The TR4 socket is physically identical to the Epyc's SPRv3 socket, but they aren't compatible. But if AMD had no plans to ever ship a 4-dice enabled Threadripper then why create the TR4 socket in the first place? They could've designed something smaller with a design that made Threadrippers cheaper to produce.
 
just brew it!
Gold subscriber
Administrator
Posts: 49696
Joined: Tue Aug 20, 2002 10:51 pm
Location: Somewhere, having a beer

Re: No Dummy Dies on Threadripper?

Wed Sep 20, 2017 10:59 am

Kougar wrote:
It is doubling the cost of diffusing the chips since all four die/dice receive the same indium/gold plating and soldering to the IHS (and also wouldn't require the use of two non-functional die which could bite them later when yields improve).

If yields improve to the point where they don't have enough defective dies, they can start using blanks. I doubt this will be necessary though; Threadripper is a niche product, and even if yields on Ryzen are very good they will probably have a steady supply of bad ones to use as spacers. Heck, they've probably got a huge pile of them already from the initial Ryzen production ramp-up.
Nostalgia isn't what it used to be.
 
Waco
Gold subscriber
Minister of Gerbil Affairs
Posts: 2032
Joined: Tue Jan 20, 2009 4:14 pm
Location: Los Alamos, NM

Re: No Dummy Dies on Threadripper?

Wed Sep 20, 2017 11:00 am

Kougar wrote:
The TR4 socket is physically identical to the Epyc's SPRv3 socket, but they aren't compatible.


I'm willing to be the physical differences are nonexistent, though. Firmware locked, perhaps, but it wouldn't make a lot of financial sense to stick with the huge packaging while also creating a physically different package.
Z170A Gaming Pro Carbon | 6700K @ 4.5 | 16 GB | GTX Titan X | Seasonix Gold 850 | XSPC RX360 | Heatkiller R3 | D5 + RP-452X2 | Cosmos II | Samsung 4K 40" | 480 + 240 + LSI 9207-8i (128x8) SSDs
 
DragonDaddyBear
Gerbil Elite
Posts: 651
Joined: Fri Jan 30, 2009 8:01 am

Re: No Dummy Dies on Threadripper?

Wed Sep 20, 2017 11:07 am

Waco wrote:
Kougar wrote:
The TR4 socket is physically identical to the Epyc's SPRv3 socket, but they aren't compatible.


I'm willing to be the physical differences are nonexistent, though. Firmware locked, perhaps, but it wouldn't make a lot of financial sense to stick with the huge packaging while also creating a physically different package.

At minimum the tracing for memory would be different as it has more and they would route to the now-confirmed-dead dies (or dice if you prefer).
 
Waco
Gold subscriber
Minister of Gerbil Affairs
Posts: 2032
Joined: Tue Jan 20, 2009 4:14 pm
Location: Los Alamos, NM

Re: No Dummy Dies on Threadripper?

Wed Sep 20, 2017 11:14 am

DragonDaddyBear wrote:
Waco wrote:
Kougar wrote:
The TR4 socket is physically identical to the Epyc's SPRv3 socket, but they aren't compatible.


I'm willing to be the physical differences are nonexistent, though. Firmware locked, perhaps, but it wouldn't make a lot of financial sense to stick with the huge packaging while also creating a physically different package.

At minimum the tracing for memory would be different as it has more and they would route to the now-confirmed-dead dies (or dice if you prefer).


On the motherboard, sure, but there's no real reason to change the package itself for that.
Z170A Gaming Pro Carbon | 6700K @ 4.5 | 16 GB | GTX Titan X | Seasonix Gold 850 | XSPC RX360 | Heatkiller R3 | D5 + RP-452X2 | Cosmos II | Samsung 4K 40" | 480 + 240 + LSI 9207-8i (128x8) SSDs
 
ludi
Darth Gerbil
Posts: 7444
Joined: Fri Jun 21, 2002 10:47 pm
Location: Sunny Colorado front range

Re: No Dummy Dies on Threadripper?

Wed Sep 20, 2017 12:22 pm

Waco wrote:
I'm willing to be the physical differences are nonexistent, though. Firmware locked, perhaps, but it wouldn't make a lot of financial sense to stick with the huge packaging while also creating a physically different package.

It might if it allows you to remove or simply blank out a few pesky layers from your package substrate.
Abacus Model 2.5 | Quad-Row FX with 256 Cherry Red Slider Beads | Applewood Frame | Water Cooling by Brita Filtration
 
Waco
Gold subscriber
Minister of Gerbil Affairs
Posts: 2032
Joined: Tue Jan 20, 2009 4:14 pm
Location: Los Alamos, NM

Re: No Dummy Dies on Threadripper?

Wed Sep 20, 2017 12:44 pm

Perhaps. I'm not an expert on what it costs to produce the substrates. I'd be surprised if it was worth keeping two separate parts running through two fab lines, though.
Z170A Gaming Pro Carbon | 6700K @ 4.5 | 16 GB | GTX Titan X | Seasonix Gold 850 | XSPC RX360 | Heatkiller R3 | D5 + RP-452X2 | Cosmos II | Samsung 4K 40" | 480 + 240 + LSI 9207-8i (128x8) SSDs

Who is online

Users browsing this forum: No registered users and 2 guests