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 Post subject: Re: The first "Sandy Bridge" tape-out revealed?
PostPosted: Sun Oct 11, 2009 7:21 pm 
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Joined: Sun Oct 07, 2007 6:22 pm
Posts: 105
>> Liar. Here is what came out straight of Intel's presentations back then.[/quote]
>
> Hey mr. as...., that was not the first picture out on the web.

Liar.

Attached are the three pictures which Intel showed at the Fall 2007 IDF
in Paul Otellini's and Stephen Smith's presentations (on September 18).

Each of them showed the full memory controller -- no copy and paste
needed. (Check the yellow area just above that 2nd core from the left.)

> If you look at the annotated picture then you see the copy and paste I had to do.

Your copy and paste is obvious, yes.

Why you failed to start from Intel's original pictures, I do not know.

> The memory interface contains two identical parts. It has been there all the time,
> copied many times over on the internet as a lasting proof.

As has been (is) Paul Otellini's original picture, which shows the whole
controller:

http://images.google.com/images?q=intel ... ehalem+die

gives me for example:

http://www.dvhardware.net/article21936.html
http://blogs.zdnet.com/Ou/?p=758
http://www.behardware.com/articles/687- ... 7-idf.html

I'll happily mail you the IDF presentations, which predate your rev 4 of

http://chip-architect.com/news/Nehalem_ ... lance_.jpg

by a month.


Attachments:
Picture 3.png
Picture 3.png [ 1003.72 KiB | Viewed 1045 times ]
Picture 2.png
Picture 2.png [ 893.34 KiB | Viewed 1041 times ]
Picture 1.png
Picture 1.png [ 810.47 KiB | Viewed 1050 times ]
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 Post subject: Re: The first "Sandy Bridge" tape-out revealed?
PostPosted: Sun Oct 11, 2009 9:42 pm 
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Joined: Wed Aug 08, 2007 1:43 pm
Posts: 10
Eric Bron wrote:
stupid dog wrote:
Wasn't it confirmed many times that making predictions on the microarchitecture, based on low-quality, low-resolution photos is a bad idea?

I don't see why it's worse than basing them on nothing at all

It isn't worse (not that it's better also) but any way it's just about the quality of recent predictions from Hans.

Quote:
stupid dog wrote:
Now, if Intel is able to implement double pumped FPU

I'll be interested to learn from the EE of the board with recent experience (if any) if it's indeed possible (i.e. to have the FPU at roughly 8 GHz on 32 nm) My understanding is that it's self contained in a small area so it's far easier to have it at twice the core clock than wider structures with more wiring delay

Hmm... I always thought that FPU is a most critical thing from the performance point of view which is actually holds back frequency increase. The only possibility for FPU troughput increasing is adding additional pipeline stages (which is alone not a simple task for mul/div algorithms) and as a result - increasing mul/div instruction latency. This can greatly affect "regular" FPU/SSE2 code. Also I heard that some stages already doublepumped in Intel's implementation of radix-16.

Quote:
stupid dog wrote:
and double pumped sheduler in SB

It's another subject entirely, isn't it ?

Why? Wasn't AMD/Intel choose to double uops to implement SSE2 on 64-bit FPUs. Also, if you already have doublepumped FPU, why not to use it for "regular" x87/SSEx by doubling throughput?
Hans de Vries wrote:
Eric Bron wrote:

I discussed this data dependency issue Agner who looked at AVX in great detail.
He concluded that all instructions which would give data-dependencies were omitted.


There are many SSEx instructions without data dependency which theirs 256 bit implementation was omitted to. This may point that the "second" 128-bit fpu is a bit simplier then the "first" one. Probably omitting data-dependency instriction means that the inter-fpu communications is a bit costly


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 Post subject: Re: The first "Sandy Bridge" tape-out revealed?
PostPosted: Sun Oct 11, 2009 10:59 pm 
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Joined: Fri Aug 31, 2007 10:08 pm
Posts: 217
Location: Switzerland
stupid dog wrote:
Hmm... I always thought that FPU is a most critical thing from the performance point of view which is actually holds back frequency increase. The

I remember an Intel ISSCC presentation (2003) with a 5 GHz FMA FPU @ 90 nm, I have no more the PDF with the advance program though, now I can imagine such a design can run at 8 GHz @ 32 nm, the number of pipeline stages is also quite less critcial if it runs at twice the speed of the core clock
NB: I just found this link : http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1234322

stupid dog wrote:
There are many SSEx instructions without data dependency which theirs 256 bit implementation was omitted to.

the ones with only an AVX 128 variant are the packed integers instructions, not the packed SP/DP fp instructions

stupid dog wrote:
This may point that the "second" 128-bit fpu is a bit simplier then the "first" one.


yes just a small bit since only the packed ints are missing


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 Post subject: Re: The first "Sandy Bridge" tape-out revealed?
PostPosted: Sun Oct 11, 2009 11:49 pm 
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Joined: Tue Aug 07, 2007 11:57 am
Posts: 190
Hans de Vries wrote:
no@spam.com wrote:
>> Liar. Here is what came out straight of Intel's presentations back then.

> Hey mr. as...., that was not the first picture out on the web.


Instead of coward anonymous insults now, two years after, you could
have asked me about this when I posted the first revision of this here:

Hans de Vries wrote:
at first glance:

Transistor count confirms 8MB L3 + 4 x 0.5MB L2
Significant increase in core size from 22mm2 to 29.6 mm2 due to SMT?
Other versions have only half of the I/O cells /circuits at the top
(the original die photo for this drawing had only 1 row)

This particular photo has wiring on top of the megacells which impacts visibility...

http://aceshardware.freeforums.org/nehalem-at-idf-t141.html

It was the only high res image I had available (which was from before IDF).
Instead you posted a rather denigrating remark about how silly I was to
presume an L3 cache on Nehalem.....

no@spam.com wrote:
Hans,

tsk, tsk, tsk... your analysis of the L2/L3 is seems...well... incorrect.


I think I nevertheless responded polite. I don't see anything in my reaction
which explains your aggression.......

Regards, Hans


Last edited by Hans de Vries on Mon Oct 12, 2009 12:06 am, edited 2 times in total.

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 Post subject: Re: The first "Sandy Bridge" tape-out revealed?
PostPosted: Sun Oct 11, 2009 11:58 pm 
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Joined: Tue Aug 07, 2007 11:57 am
Posts: 190
stupid dog wrote:
It isn't worse (not that it's better also) but any way it's just about the quality of recent predictions from Hans.


What "predictions" did cause your outrage? Was it that I insulted you in some way,
or did you simply dislike what I said?


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