PREVIEW: Intel 3820 (Socket 2011) Processor - OC Results!

[Reedux]

Can we get an estimate of when this chip will hit the store? I'm waiting impatiently for this to show up!

Also, this doesn't happen to come with a cooler does it? :X

 

[andybird123]

I'd just assumed that it was taking so long to release the 3820 because they were stockpiling faulty 6/8cores waiting to have enough to release the 3820

obviously it was the remask for a new chip that was the delay (and waiting for all the impatient enthusiasts like me to get bored waiting and nab 3930's so they make more money in the meantime)

 

[FreeStream]

That's very true, but the problem is you're assuming ALL the failures are in the cores, you're vastly overestimating the number of die on a wafer AND you haven't factored in you want more 3820s than 8 cores (due to the price/performance).

Let's take your example. 50% of die are good. At 435mm^2 (quoted size of the 8 core chips) you'll probably have around 130 chips on a 12" wafer - perhaps less. That gives you 65 good and 65 bad.

Now, for an 8 core device, lets assume that each core takes up 7% of the die. Let's also assume that defects are randomly scattered (not always the case). We can "lose" up to 4 of our cores. Of our 65 dies, there is a 7% chance that only one core is gone and everything else works, 14% that 2 cores are gone, 21% three cores and 28% 4 cores gone. So, of your 65 chips, only 28% of them are usable die. That's 18 good die from 65 that can be reused as 4 core chips. So from the one wafer at 50% yield for the 8 core, you have 65 8 core chips and 18 4 core chips.

Now, let's take the hit of a new mask set and spin of the design. At 297mm^2 for the 3820, you'll probably get ~200 die on a wafer. As each die is smaller, your yield will go up - let's say to 65%. So on a redesign and new mask set you'll now have 130 viable quad core die off the same wafer.

Let's assume you have an order for 1300 3820s. You can either have 10 wafers of the redesign or, given you don't have many quad cores from the 8 core wafer, you can knobble your 65 good 8 cores to be 4 cores and add your 18 4 cores from each of the 8 core wafers and process 16 wafers of 8 cores to get your 1300 quad cores. I.e. you need to produce 60% more wafers if you want to run a line of quad cores based on the 8 core die.

Don't forget, the quad cores will far outsell the 8 cores. So, as Mr Intel Sales, do you want to add 60% to the production price of your 3820s (and hit your profits accordingly) or take a one off hit and do a new mask set?

PS...



But how many are they selling? A mask set for a chip that size will be a huge cost (perhaps $10M at a guess). If you aren't selling many, or you're getting lousy yeilds it becomes more viable....

Fair play.

It just seems to me in this culture of sustainability that those 18 4 core chips are thrown away.

Whats the chances they are sold off to people as a different 4 core chip? Perhaps a 3815 or something will come along at another date?

 

[olryst]

So should I go i7-3820 or I7-2600k, to go with a HD7970, for my new gaming rig to replace my phenom II 1100T

 

[djabs786]

So should I go i7-3820 or I7-2600k, to go with a HD7970, for my new gaming rig to replace my phenom II 1100T

In my opinion, 2600k, unless you need the quad-channel memory and or want to go into Crossfire later on, where in that case i'd go for X79 or wait for Ivy Bridge.

 

[Buckster]

surely if going 2600k you may as well pay the small delta and go 2700k - at a minimum the resale value will be slightly higher at a later date (about 20 quid in it ?)

I'm 50:50 between 3820 and 2700k

 

[Buckster]

Legitreviews has a new review up and its very positive re the 3820

http://www.legitreviews.com/article/1845/1/

 

[rare]

Still tempting this one. Even though ivy seems more logical if I keep waiting I won't ever buy a pc. At least this gives you level performance to a 2700k plus the benefits of x79 and the opurtinity to upgrade the CPU towards the end of the year.

Hmmm. Tempting.

 

[Buckster]

my only concern with this upgrade path - is will there be a similarly affordable Ivy-E processor ?

 

[rare]

I was thinking the same. Don't want to have to spend £500+ in a years time to upgrade the cpu...

 

[olryst]

Anyone know how the 3820 would compare to ivy bridge.

Would I be better off with the 3820 if I got 2 7950s?

 

[Helios1234]

Anyone know how the 3820 would compare to ivy bridge.

Would I be better off with the 3820 if I got 2 7950s?

Ivy Bridge is meant to be around 5-7% better than the current Sandy Bridge CPUs, but going X79 gives you the option of going Ivy Bridge-E later on in the year. Regardless, there's no point waiting so just get a 3820.

 

[BlackAle]

Wouldn't have a problem is you had a 30" like what Gibbo and myself are currently using

Great customer relations, be condescending.

 

[mmj_uk]

Anyone know how the 3820 would compare to ivy bridge.

Would I be better off with the 3820 if I got 2 7950s?

Ivy Bridge is manufactured on 22nm process, so there's a good chance it will do 5ghz standard (at worst ), I'm hoping 5.2ghz+ personally.

3820 will give you 16x/16x Crossfire but I'd take the 500Mhz or so extra CPU speed personally, even at 8x/8x games should be much faster with the extra CPU power.

If Ivy Bridge is released in March then the wise thing to do would be to wait and see what develops.