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7 here is a practical limit on
how much heat a chip can
handle before going pop, and
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goal is more performance per
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go pop anymore, either; there
are sensors and systems that
throttle back or close down
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Overclocking used to be a
potentially expensive practicH
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supposedly the most heat it
can generate, for which you
have to allow cooling,
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with boost engaged, it will
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you can make it do this all
the time if you delve into the
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to silly numbers, so boost
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higher levels of cooling, it
turns up the heat, or vice
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margins and responses to
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it’s a hard number, it is used
as a point of competition
between Intel and AMD in
their marketing, despite the
fact that it is not directly
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as inventing a new measure,
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you may have guessed,
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guide as to how much cooling
you need above anything
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you know you need a big
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action is another matter,
because there are so manyvariables at play – ORZ7'3
chips may still idle high, while
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right down while not doing
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they’re a guide only, and if in
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cooler – LWFDQ·WKXUWhat micro-
architecture do you
have? Simple question,
but the names given to
processors don’t help.
For example, Intel’s full
name for the Core i7-8700 is the 8th
Generation Intel Core i7-8700. Let’s
break that down. ‘Core’ indicates that
the basic architecture is based on Intel’s
multi-core processor model. So, what’s
an ‘8th Generation’ chip? Intel has
loosely divided its Nehalem Core chips
into generations. Nehalem was actually
the third Core architecture, the first
ones being Core and Core 2. Then it
decided to go back to the brand name
Core, and when it thinks it has made
significant improvements, Intel blesses
the chips with a new generation. There
are no rules really, so it’s just an
indication of how new the design is.
Eighth-generation chips generally have
more cores than seventh-generation
ones; other than that, they’re pretty
much the same, bar some cache and
memory bumps. The latest ninth-
generation desktop chips have
hardware protection from the
Meltdown and Spectre vulnerabilities,
and very little else.
The ‘i7’ part of the name is pure
marketing; it indicates nothing more
than that Intel considers this chip to be
toward the high end. The ‘8700’ also
equates to little more than where it
stands against Intel’s other chips. The
name may help place a chip into a
marketing scheme, but tells you little
else. The i7-8700 is a Coffee Lake chip.
This defines the starting parameters of
what it can do, but you have to dig
around in the specifications to find out
exactly what you’re buying.
Coffee Lake is a refinement of
Skylake – Intel’s code names can get
confusing. Skylake is the micro-
architecture design, the fundamental
part that does the number-crunching.
This has been through two major
revisions, which get their own
separate code names.
2016’s Kaby Lake was a refinement of
the design, dubbed the 14nm+ process.
It also got some useful hardware video
encoding/decoding extras (Intel has a
dedicated video processing unit called
Quick Sync Video, which handles
encoded video streams), and support
for USB-C and Optane.
In the autumn of 2017, we got Coffee
Lake, a further refinement using a
14nm++ process. Performance insidethe cores remains pretty much the
same across all these iterations.
In the X-Series, you’ll find Skylake-X
and Kaby Lake-X cores for HEDT
systems, with up to 18 cores, and
$2,000 (£1,548) a pop. There are some
oddities still available, too, such as the
Intel Core i7-5775C, which is based on
the fifth-generation Broadwell core.
Somebody must still want this for
some reason we can’t fathom.
Intel basically produces one main
desktop processor architecture – it has
been shrunk, optimised, had cores
added, and cache changed, but at its
heart, Intel’s desktop chips have shared
a common design heritage since 2015:
Skylake. AMD has its Zen architecture,
launched in the spring of 2017, Zen+
being an optimised version. So, there
are just two main desktop micro-
architectures, despite the profusion ofAMD’s Zen arranges its cores into CPU complexes, or CCXes. Here there’s two with four cores each.
Between them sits the L3 cache, shared between each CCX.56 |^ |^ January 2017