SB-E could unlock to 8 cores?

E

EpsilonZer0

Weaksauce
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Oct 5, 2011
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Ok, first read this article from VR-Zone.

Why the initial desktop Sandy Bridge-E chips has only six (of eight) cores enabled?

There was disappointment in some of the enthusiasts' circles that the initial round of desktop Socket 2011 Sandy Bridge E processors have one quarter of their cores and cache disabled. So, instead of 8 cores with 20 MB L3 cache, you get just 6 cores with 15 MB L3 enabled. The reasons mentioned, better to say speculated, along the way, were anything from the yields on this large die, or Intel's preference to sell full 8 core versions to the more lucrative workstation and server Xeon market, or even the fact that desktop apps or environments can still barely use even those 6 cores, not to mention a full set of eight.

SNB_E_oc.jpg.jpeg


There's another reason, that may top them all though - TDP. Yes, these are really big dies, with many cores and lots of cache - not as many as the Xeon E7 - Westmere-EX - series in the same 32 nm process, but E7's 10 cores and 30 MB cache top out at 2.4 GHz only. Here, we have an expectation that the full 8 core chip should still work at just above 3 GHz right at the announcement - at least in the '3-D workstations only' 150 W version. See the number? Now, well, desktops don't really go with more than 130 W TDP per socket these days, yet the per core clock has to be higher, to justify the migration from older Core i7, and to keep the difference with the LGA1155 4-core SB chips, as well as AMD Bulldozer.

So, to get 3.3 GHz or higher core speed, and fit it all into 130W TDP, a 6 core limit sounds about right for the current C series steppings at least. A future D stepping could enable higher clocks at the same TDP, or maybe enabling all the cores too at a similar speed. Intel's tradition for both Nehalem and Westmere was that, a quarter or two after the initial stepping, the next one would bring substantial improvements in frequency, or power, or both - usually one or two speed bumps within the same envelope. That was enough then, there's no reason to doubt it will be the same this time.

Else, we'd have to wait for the Ivy Bridge-E generation, still a year away...

http://vr-zone.com/articles/why-the...eight-cores-enabled-/13748.html#ixzz1b0ZnMWWs
Click to expand...

So taking what we now know, the 6 core SB-E chips actually contain 2 more cores but they are locked due to power requirements.....

wouldnt it then be possible for a mobo company like EVGA to step up with a 150W TDP and have an unlocking feature?

We have seen this done with AMD chips in the past, so depending on the method that Intel locks their chips, one could buy the SB-E 3930K and walk away with a very cheap SB-E 8 core Xeon.

Thoughts?
 
fuck this post now i am going to buy a 2600k @ 220 and not even open the box since sb-e comes out november i can only afford the non-unlocked 3820 though wold that be a 6core??
 
MOAR CORES!!!!!

Seriously, 8 cores of Sandy Bridge at 5+ ghz is just pure awesomeness.
 
I think its the ring bus that makes SB-E so power hungry. Even Intel with all their technology still doesn't have a perfect process.
 
How do you know how much power SB-E uses? The ring bus is actually pretty efficient power wise, but that chip just has some serious horsepower, that's where the watts come from!
 
we know why they include water cooling now! that would be very interesting to see if you could unlock to a higher count.
 
Or, it could be a manufacturing flaw. With a die that large and that many transistors, it's bound to happen.
 
I bet its a mfg flaw where the extra cores aren't stable so they sell them as 6 core only....
 
Why don't you guys just buy the Xeons? The single socket Xeons have always costed about the same as the i7`s, with the high-end stuff having unlocked multiplier. You also get as a bonus better binning (thus lower voltage, thus higher overclocks) and ECC support (stick in a server board bought off eBay 5 years later for a home server).
 
iconiK said:
Why don't you guys just buy the Xeons? The single socket Xeons have always costed about the same as the i7`s, with the high-end stuff having unlocked multiplier. You also get as a bonus better binning (thus lower voltage, thus higher overclocks) and ECC support (stick in a server board bought off eBay 5 years later for a home server).
Click to expand...

This. With clock multiplier there's a chance even 8 core 2 Ghz Xeon could work at 4 Ghz per core without touching multipliers.
 
Has Intel ever used BIOS-level locking for anything, as opposed to on-chip physical locking? I don't remember Intel having any history of making things "unlockable" - at least not since they locked down their multipliers back in the P3 days.
 
if they do have 8 cores and 2 are disabled i would bet anything that intel fuses off the other two cores. you really think intel would allow you to unlock 2 core for nothing? you cant even overclock sb unless you have a k model.
 
also considering power usage would go through the roof with overclocking there is no way you will be able to unlock them.
 
Namesis said:
we know why they include water cooling now! that would be very interesting to see if you could unlock to a higher count.
Click to expand...

Did I miss something? (Entirely possible.) What do you mean about "they" "include water cooling?"
 
EpsilonZer0 said:
wouldnt it then be possible for a mobo company like EVGA to step up with a 150W TDP and have an unlocking feature?
Click to expand...

no. this is the company that just celebrated inventing the microprocessor circa probably when your parents were fetuses. they don't mess up like amd. they make their living using lasers to disable parts of chips to sell them for less.
 
Michaelius said:
This. With clock multiplier there's a chance even 8 core 2 Ghz Xeon could work at 4 Ghz per core without touching multipliers.
Click to expand...

This would be impossible because the maximum RCR value (based on information leaked so far) is 1.66. That means your maximum clock speed would be 1.66 times the stock clock speed, most likely a tiny bit more since you can probably increase the base clock to around 105.
 
From where is this ideea that the 6 cores are 8 cores with 2 disabled ?

Since Xeons are pretty large volume, I wouldn't be suprised to have 2 dies : an 8 core one and a 6 core one ( that also gives 4 with 2 cores disabled ).
The volume is in the 6 core parts. It doesn't make sense (looking at Xeon 1P and 2P) volume to ship8 core dies with 2 cores disabled.
 
savantu said:
From where is this ideea that the 6 cores are 8 cores with 2 disabled ?

Since Xeons are pretty large volume, I wouldn't be suprised to have 2 dies : an 8 core one and a 6 core one ( that also gives 4 with 2 cores disabled ).
The volume is in the 6 core parts. It doesn't make sense (looking at Xeon 1P and 2P) volume to ship8 core dies with 2 cores disabled.
Click to expand...

Because it costs a LOT MORE to design a second die, even if it's mostly copy-paste. With the margins on workstation and server parts, Intel has no problem with doing a dual-core version of the 8-core die and STILl getting a healthy profit.
 
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