Why the xbitlabs Thuban review is junk - author exposed.

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jennyh

Splendid
The pre-review "Thuban is instanbul for desktop"

Remember that from 6 months back? How the author oh so confidently told us

we expect AMD Thuban processors to work at about 3.0 GHz. And as we have seen during our today’s test session, it won’t be enough for them to outperform neither competitor’s six-core solutions, nor top quad-core Nehalem based CPUs, which cope perfectly well with heavy multi-threaded load due to Hyper-Threading technology support.

I guess if you already have stuck your neck on the line 6 months before the chip is even available...

The real review of Thuban


Same website, same author. I don't know what is up at xbit but at the very least a different reviewer should have reviewed the actual chip after the joke that was the "istanbul for desktop" article. That very article was the basis for people like Fazers, jimmysmitty and Chad to declare Thuban would be no better than the i5 750. :lol:

As usual, you need to be very careful about who you believe. Some websites cant be trusted - xbit has proven itself untrustworthy over the recent months.
 
^ Actually it was the much more recent Taiwanese review that sorta confirmed for me that Thuban, which is basically a stopgap CPU until Bulldozer comes out, would not be the "world's fastest desktop CPU". Which incidentally falls under your "need to be very careful about who(m) you believe" cautionary statement :D.

AMD took some economies with Thuban - same size L3 cache despite 50% extra cores, rather simplistic turbo solution, no improvement in memory bandwidth, no IPC improvements, etc. To me, that indicates AMD did a quick, minimal job with it in order to keep the AMD loyal in their camp until BD arrives. I would imagine BD is getting all the R&D funds & effort for some time now.
 
Haha. I read that article a long time ago. The performance numbers make sense but how would it be a preview of future possible thuban if he didn't overclock the opteron to at least 3GHz? His conclusion makes it sound like he did overclock to 3GHz when he didn't.
 

jennyh

Splendid
Wow you totally avoided the point altogether there didn't you fazers?

The point is, the xbit review is a sham review because the author had already made up their mind long before the actual chip was released.

So that's one less anti-thuban to subtract from the legions of pro-thuban reviews out there. :)
 

theholylancer

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but hell, you can't argue that it is not better than the 750, you can argue that the 930 is the king of gaming and get away with it, but not when the 1055 beats the 750 on price of platform and can be OCed regardless of what others are saying about it.

from my point of view, either clock for clock comparision, price per price comparision (then it'd be 965 or 955), or OC comparision

and in all instances, amd wins, either with a 955/965 or a 1055T


with the 1090T there is less of a win against the i7-920/930, and can be said to be on more equal footing.

but considering that the 1055 don't cut much from the 1090 (same platform, no gimped cores, same turbo, no fucked pcie 2 lanes >.> stares at 1156s) after OC it becomes 1055T vs 920/930 and in that comparision, if i was building new I'd go 1055T every way for the savings to put towards a better gfx. for me personally tho, not so much for anyone else with bigger budgets.


but i have to say, remember that intel can release a 300 dollar 6c/12t with turbo i7-935 and say $500 i7-965 that can simply blow things away. will they do it is another issue tho. Or if you are an intel fanboi, believe that intel can bring in 8 core neth-ex (without the added QPI links) to the desktop on demand and completely crush amd's higher end again.
 


Why are you bashing him now instead of 6 months ago?
 

jennyh

Splendid
And come on fazers.

Do you actually believe GF would put all that effort into perfecting their 45nm for what you call a 'stop gap' cpu? That doesn't make sense.
 


No, I rebutted your point that it was the XBitLabs article that made me think Thuban wasn't going to be as spectacular as you are spending far too much time trying to make it appear to be.

C'mon - look at the facts: AMD has confirmed there are no core tweaks to Thuban - it's basically a Phenom 2 quad with 2 additional cores, no additional L3 cache, but with low-K dielectric so as to reduce power consumption as well as a sort of 3-on/3-not-quite-so-on Turbo feature.

Taking your Neoseeker benchmark analysis from the other thread, the 1090T was 27.5% ahead of the i7-920 in the highly threaded benchmarks. Seeing as how all the cores were being used, I doubt think either CPU was in turbo mode, so comparing them IPC-wise they would be about equal, since the Thuban has a 23% higher base clock rate. So in other words, it takes 6 physical cores for AMD to match 4 physical + 4 'fake' cores (which offer a range of -10 to +25% advantage depending on the app being run, according to the AMDZone "experts" like Scientia).

In the gaming & other low-threaded apps, it seems Thuban is about the equal of the 920, despite the 600MHz stock clock advantage and the 100MHz turbo clock advantage, which doing a simple average is a 650MHz total clock advantage.

If turbo is turned off and both Thuban & the 920 oc'd to 4GHz, then it appears the 920 will beat Thuban in most of the benchies. Of course, very few users oc.

My point is - it took AMD 18 months to catch up to the lowest-speed Nehalem, at the expense of far larger die size and 50% more physical cores. The latter is a losing game for AMD since Intel is a generation ahead on process and can cram a higher number of more efficient cores onto a given die size than AMD can. Yes it does appear that AMD gets its CPUs fabbed cheaply from GF nowadays, but that is a deal that cannot last forever as GF has to spend the same (or more, since Intel is a large shareholder in some of the fab equipment manufacturers and probably gets something of a discount) on capital equipment during the process node upgrades.

So IMO Bulldozer is the make-or-break CPU for AMD and that's where they are spending most of their time & dollars. If BD lives up to the hype, I'll switch to AMD for my next build. However Thuban is simply not a compelling choice for me.
 


No - I'm sure GF is working on yields for their own profitability and to fill up the Dresden fab with orders. Isn't it about 30% underutilized as of last quarter? I seem to recall somebody mentioning that during the AMD Q1 statement thread.

It was AMD's design effort that I was referring to, when I said IMO it was a stopgap CPU to tide people over until Bulldozer.

BTW, did you see the report yesterday about TSMC making a large jump in their quarterly profits for Q1? I guess it's all the other foundry work they do and not so much the 40nm yield issue for AMD & nVidia GPUs...
 

jennyh

Splendid
Why is it always 'because intel COULD' fazers?

If intel COULD they WOULD. Yields are pathetic on Gulftown thats why you can't get hold of them. Why do you think Apple are so upset with intel too? A total lack of 32nm chips except the *tiny* clarkdales.

No fazers, intel *can't* just make mainstream 6 cores - at least not profitably. If they could, they would.
 


Hmm, the two Intel engineers who post here unofficially, Sonoran and Archibael, have both disputed your claim about 32nm being "pathetic" for Intel - I tend to believe them since they are in a far better position to actually know rather than make a lot of assumptions. For one thing, I think it was Sonoran who mentioned that during the 32nm ramp-up they have to prioritize which CPUs to make, and that is based on a market analysis and the decisions have a rather lengthy lead time of 6 months or more.

Where do you get that "Apple are so upset with Intel"? All I've seen are a bunch of rumors based on some AMD execs riding on an Apple bus around Cupertino, or some such. Could be that their 1970's Gremlin broke down and they had to thumb a ride with what turned out to be the Apple bus :D. Or it could be that AMD has shown some ES samples to Apple and they are interested.

But, let's turn the tables, shall we?? Since Thuban is basically just a P2 with 2 extra cores, why did it take AMD a year or more to produce it, esp. after Istanbul which is also 45nm and 6 cores?

OK, this is starting to degenerate into hyperbole and ridiculousness, instead of my newfound persona of exuding thoughtful insight :p, so pardon me while I take a tranquilizer and meditate upon my navel lint a while. I suggest you do the same, OK?? :kaola:
 

archibael

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Gulftown would not have made it to market if the yields were "pathetic", because they indeed would have been less profitable were that the case and a Return on Investment calculation would have been done and determined that there was better money to be made making more Arrandale and Clarkdale.

Who can't get hold of them? I see them on Newegg right now.

It's a premium part, and it costs more to reflect 1) the expected price people would be willing to pay to obtain it and 2) the R&D which had to go into producing it. But don't fool yourself into thinking yields drive up the costs on this chip.
 

Chad Boga

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Jenny you insane liar, where/when did I ever predict the Thuban would be no better than the i5-750?

Jenny, do you feel embarrassed for saying that with Thuban, AMD's share price would overtake Intel's within one week of Thuban's release? :lol:

we expect AMD Thuban processors to work at about 3.0 GHz. And as we have seen during our today’s test session, it won’t be enough for them to outperform neither competitor’s six-core solutions, nor top quad-core Nehalem based CPUs, which cope perfectly well with heavy multi-threaded load due to Hyper-Threading technology support.
This quote turned out to be perfectly true, so what are you whinging about?

 




You are both correct in part. Sonoran's commentary about Intel being early in their 32 nm fab ramp-up and needing to prioritize what chips get made on 32 nm means that Intel can't make mainstream 32 nm chips. It's not that they are unable to make said chips (they are making bigger and smaller ones for revenue, so the process obviously works), they simply don't yet have as many fab lines as they would need to yield those chips in the necessary quantities. I couldn't tell you what yields on Gulftowns/Westmeres are, but they will be lower than 45 nm yields simply because it's a new process and hasn't had time to be optimized like 45 nm has. That's a well-known phenomena that affects everybody, not just Intel. AMD didn't roll out 45 nm to their entire chip line all at once, either.

Where do you get that "Apple are so upset with Intel"? All I've seen are a bunch of rumors based on some AMD execs riding on an Apple bus around Cupertino, or some such. Could be that their 1970's Gremlin broke down and they had to thumb a ride with what turned out to be the Apple bus :D. Or it could be that AMD has shown some ES samples to Apple and they are interested.

Apple would be stupid to not occasionally talk to AMD and "investigate" using their products. At the very least, it would allow them to get a better bargaining position with Intel when they negotiate the next order for CPUs.

But, let's turn the tables, shall we?? Since Thuban is basically just a P2 with 2 extra cores, why did it take AMD a year or more to produce it, esp. after Istanbul which is also 45nm and 6 cores?

I'll bet it has to do with AMD doing a new stepping for the Magny-Cours server CPU. MC was a long time coming since it was a major platform change for AMD. The dies in the Magny-Cours are virtually identical to the Thuban die with DDR3 support and the D1 stepping. They also were released quite recently as well (March 29th.) The D0 Istanbul had about a 140 W TDP at 2.8 GHz. The new-stepping D1 dies are able to do 3.2 GHz at a 125-watt TDP envelope, which is far more competitive than a 2.8 GHz, 140-watt unit would have been. Plus, I bet AMD's yields have improved over the yields they initially had when Istanbul was released, so they could release at a lower price and still make money.
 

ksampanna

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+1
 


Um hey, don't throw me in there I said on par with a Core i7 930 and I am not that far off. Most of the reviews show the 930 and the 1090T trading blows both at stock and both OCed and in most cases, are on par.

But the reviewer was right on one part. Thuban cannot beat Gulftown. Thats a true fact. In most cases a stock 980X beats a 4GHz Thuban.

I do love your guesses on Intels yields.

http://www.newegg.com/Product/Product.aspx?Item=N82E16819115223&cm_re=980X-_-19-115-223-_-Product

That alone says its available.

So I guess now you will go through every review not praising Thuban as an amazing chip and try to discredit the authors?

BTW, you can't get mad at an author for making a prediction. They do it all the time.
 


This is really kind of silly statement. You obviously haven't followed processor development much over the years. This type of incremental improvement is par the course from intel and AMD.

Far from have taken "economies" or "quick minimal" as you put it, the addition of even a primitive turbo function to an architecture not designed with it in mind was a surprise. Memory bandwidth improvements would not be expected at this stage, nor would core level IPC improvements. L3 cache increase was precluded by the size of the die at 45nm.

This is the type of post we see too often. People just make stuff and post it like its fact. I don't get it.





 

notty22

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Do You have a link to back that statement up ? Smaller cache size or less is seen in both AMD and Intel chips up and down the product lines. And all else being similar more expensive cpu's have more cache and the lower variants less.
Celerons and Athlons.
e8400's vs e7400.
 


And of course that is merely your opinion. You should indicate it as such, as I did mine.

If the 45nm die size is such a constraint, then explain Magny Cours with its whopping 346 x 2 mm die size. Clearly AMD could have made a bigger die with more L3, although they would also likely have to raise the price. So, yes - AMD took economies with the design. And I'm not the only one with this opinion - from http://www.brightsideofnews.com/news/2009/5/14/amds-magny-cours-architecture-revealed.aspx:

So, is AMD architecturally doing a better job than Intel for these MCMs? Let's look at what we should be having here: The G34 substrate features two 45nm dies - each with six cores and private 512K L2 per core, sharing a - probably undersized - 6M L3 cache per die. I feel that AMD, having been on the forefront of dense cache memory cell technologies [anyone remember Z-RAM?], should have added a bit more here when they decided to jump from 4 to 6 cores. Remember, Core i7 and Gainestown Nehalems [Nehalem-EP] have 8 MB L3 per four cores, fed by a 216-bit Triple-Channel DDR3 while Beckton [Nehalem-EX] will have 8 cores and 24 MB L3, fed by a 288-bit Quad-Channel memory controller. So, for more memory intensive threads, where Istanbul has 6 MB L3 per 6 cores, and fed just by 144-bit Dual-Channel DDR3, the cache increase would have been helpful as long as the latency is managed.

Perhaps you should take note that Thuban uses the same old 3-issue K8 core, albeit with a few tweaks, which means they have been sitting on that design since what - the last 8 years now? So yes most people would have expected some core-level IPC improvements by now - after all, Intel went from P4 to 4-issue Core2 during that time period, and Sandy Bridge is also expected to make some significant core changes. If SB makes it to market before Bulldozer, that would be two major IPC improvements for Intel and zero for AMD in roughly 9 years time.

I would hardly call the 30+% IPC improvement of Core2 "incremental", but then I'm not an AMD-favoring history revisionist either.

And seriously - a bolt-on turbo function is a surprise to you? What I find surprising is how long it took AMD to release Thuban, in view of Istanbul coming out early last summer, and yes I have heard about validation cycles.

You are relatively new here, but already you are coming across as yet another AMD know-it-all who thinks he's a walking encyclopaedia of CPU facts & history, which is another thing we are seeing too often. You obviously have two very different standards of performance - a low one for AMD and likely an impossible one for Intel.
 


This is what I am talking about! Nobody who follows chip development would have to ask. These types of incremental development are common.

I will give you two examples from each manufacturer.

Intel --

1) The I7 980X! Its nothing more than a I7 quad with 2 additonal cores and extra L3 which was only possible due to the die shrink.

2) Core 2 quads. Two core 2 quads on a single die, talking though the northbridge.

AMD

1) Single core A64 to the X2. No significant changes except 2 integrated cores on a single die.

2) Agena Phenoms to Deneb Phenoms. This was nothing but a die shrink.


You go on for hours if you really wanted to. This is how chips usually evolve. A little bit at a time.
 

notty22

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You had a hissy fit about people 'making up things' and then and I may add poorly tried to reason what AMD did or didn't do , on three points with Thuban. When asked to back that up, with links you can't.
So all you have is your opinion, after whining about other people. Hypocrite.
 

jennyh

Splendid


Once again simple common sense and logic evades you Fazers.

Die size isn't the contraint, if anything it's TDP. The 1090T is a 125w CPU at 3.2ghz and 6 cores. Magny cours is 130w 12 cores at 2.3ghz (or thereabouts). Do I need to remind you about Gulftowns 6 32nm cores at 140w TDP btw?

One of these makes a good desktop cpu, the other makes a good server cpu - and it has got nothing to do with die size constraints.
 

No its not my opinion. It would have been foolish to add L3 cach at this die size. With 12 megs of L3 cache, the thuban would be almost 450 mm! And thats less than 10% speed improvement.

350 mm is a huge die as it is. Die size affects power usage, cost and yield amongst other concerns. The problems presented by the additonal die space needed far far outweigh the small speed gain.

If you think this was a viable option on a desktop chip, then you don't understand the technology.

Perhaps you should take note that Thuban uses the same old 3-issue K8 core, albeit with a few tweaks, which means they have been sitting on that design since what - the last 8 years now? .

Actually, the K8 is nothing more than a K7 with 64 bit instruction set and an on die memory controller.

And they have made core level IPC improvements in that time. Don't know where you get the idea they didn't but they have been INCREMENTAL.

Intel went from P4 to 4-issue Core2 during that time period, and Sandy Bridge is also expected to make some significant core changes..........................................I would hardly call the 30+% IPC improvement of Core2 "incremental", but then I'm not an AMD-favoring history revisionist either.
No your not an AMD favoring revisionist. Unfortunately, your not well versed on the topic either.

Core 2 didn't just magically appear in 2006. It was developed INCREMENTALLY as an extension of the P3 architecture and later Pentium M for laptops and was simply moved to the desktop.

It appears to be a huge jump ONLY because it replaced Netburst. But if you follow its parallel development history, it improved INCREMENTALLY.

And seriously - a bolt-on turbo function is a surprise to you? What I find surprising is how long it took AMD to release Thuban

Funny that no knowledgeable source shared this view. Like I said, you don't understand the technology.
You are relatively new here, but already you are coming across as yet another AMD know-it-all who thinks he's a walking encyclopaedia of CPU facts & history......

Your being wrong doesn't make me a walking encyclopedia. But thanks anyways for the complement. :)
 
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