Comment by listic | Hacker News Reader

Comment by listic | Hacker News Reader

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Just how custom is the E5-2676 v3 processor?

I see this paticular model is not in the Intel's list of models [1] nor in the Wikipedia [2].

I suspect that, as the model number suggests, it is virtually identical to E5-2670 v3 [3] and 100 MHz higher base clock rate and 100 MHz lower Turbo Boost frequency is all customization there is (but what about the exact turbo profile?), but the fact that Intel does it at all, even for a customer as large as Amazon (how much are they ordering, actually?), is an interesting development.

[1] Intel® Xeon® Processor E5 v3 Family http://ark.intel.com/products/family/78583/Intel-Xeon-Proces...

[2] Wikipedia: List of Intel Xeon microprocessors http://en.wikipedia.org/wiki/List_of_Intel_Xeon_microprocess...

[3] Intel® Xeon® Processor E5-2670 v3 (30M Cache, 2.30 GHz) http://ark.intel.com/products/81709/Intel-Xeon-Processor-E5-...

All those different models you see in the E5v3 product line aren't separate products, they're bins of probably just 2-3 different CPUs. Many of the chips made will have defects, and the number of working cores, their maximum stable frequency, and their thermal properties determine which product number they get sold as. Amazon probably just gets one of these bins: the chips that come out of testing meeting their specs are sold to them as a 2676. Intel doesn't actually have to custom design any hardware.

http://en.wikipedia.org/wiki/Product_binning

It's probably easy for Intel to reclassify the processors since Amazon probably provides the exact thermal conditions they will be in. If you say that the CPU temperature won't exceed X degrees due to the cooling systems, you can push the core clock speed higher.

There's a Hamilton talk at the last reinvent where he kinda implies what's going on. Because Amazon is running in a datacenter and can guarantee the temperature, they are able to make assumptions and clock the chip less conservatively.

http://www.slideshare.net/mobile/AmazonWebServices/spot301-a...

Oracle also has custom SKUs. It's just different fuses and since Intel already makes a dozen SKUs from each die it's easy for them to make one more. Personally, I'm thinking of ordering an 11-core SKU.

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