Ivy bridge vs Sandy bridge Micro-architecture.

Ivy bridge vs Sandy bridge Micro-architecture.

1. Sandy Bridge / Ivy Bridge Microarchitecture
MICROPROCESSOR TERM PAPER

Sumit Khanka
Bachelor of Technology (Computer Science Engineering), 11103349
[email protected]
Lovely Professional University
Jalandhar, India


Abstract— this document explains and differentiate between
the Intel’s Sandy Bridge and Ivy bridge microarchitecture in
detail.
Keywords—microprocessor, clock speed, Opcode, Instruction
fetch, system archicture.)
I. INTRODUCTION
Ivy Bridge and Sandy Bridge are both the microarchitecture
developed and designed by Intel corporations. In this document
I’ll be comparing both the microarchitectures on the basis of
technology, speed and graphics.
II. SANDY BRIDGE MICROARCHITECTURE
A. Introduction and History
Sandy Bridge is the codename for a microarchitecture
developed by Intel beginning in 2005 for central processing
units in computers to replace the Nehalem microarchitecture.
Intel demonstrated a Sandy Bridge processor in 2009, and
released first products based on the architecture in January
2011 under the Core brand.
B. Technology
Developed primarily by the Israel branch of Intel, the
codename was originally "Gesher" (meaning "bridge" in
Hebrew). The name was changed to avoid being associated
with the defunct Gesher political party; the decision was led
by Ron Friedman, vice president of Intel managing the group
at the time. Intel demonstrated a Sandy Bridge processor with
A1 stepping at 2 GHz during the Intel Developer Forum in
September 2009.
Upgraded features from Nehalem include:
 32 KB data + 32 KB instruction L1 cache (3 clocks)
and 256 KB L2 cache (8 clocks) per core.
 Shared L3 cache includes the processor graphics
(LGA 1155).
 64-byte cache line size.
 Two load/store operations per CPU cycle for each
memory channel.
 Decoded micro-operation cache (uop cache) and
enlarged, optimized branch predictor.
 Improved performance for transcendental
mathematics, AES encryption (AES instruction set),
and SHA-1 hashing.
 256-bit/cycle ring bus interconnect between cores,
graphics, cache and System Agent Domain.
 Advanced Vector Extensions (AVX) 256-bit
instruction set with wider vectors, new extensible
syntax and rich functionality.
 Intel Quick Sync Video, hardware support for video
encoding and decoding.
 Up to 8 physical cores or 16 logical cores through
Hyper-threading.
 Integration of the GMCH (integrated graphics and
memory controller) and processor into a single die
inside the processor package. In contrast, Sandy
Bridge's predecessor, Clarkdale, has two separate
dies (one for GMCH, one for processor) within the
processor package. This tighter integration reduces
memory latency even more.
 A 14- to 19-stage instruction pipeline, depending on
the micro-operation cache hit or miss.
III. IVY BRIDGE MICROARCHITECTURE
A. Introduction and History
Ivy Bridge is the codename for a line of processors based on
the 22 nm manufacturing process developed by Intel. The
name is also applied more broadly to the 22 nm die shrink of
the Sandy Bridge microarchitecture based on FinFET ("3D")
tri-gate transistors, which is also used in the Xeon and Core i7

2. Ivy Bridge-EX (Ivytown), Ivy Bridge-EP and Ivy Bridge-E
microprocessors released in 2013.
Ivy Bridge processors are backwards compatible with the
Sandy Bridge platform, but such systems might require a
firmware update (vendor specific). In 2011, Intel released the
7-series Panther Point chipsets with integrated USB 3.0 to
complement Ivy Bridge.
Volume production of Ivy Bridge chips began in the third
quarter of 2011. Quad-core and dual-core-mobile models
launched on April 29, 2012 and May 31, 2012 respectively.
Core i3 desktop processors, as well as the first 22 nm Pentium,
were announced and available the first week of September,
2012.
B. Features and Performance
The mobile and desktop Ivy Bridge chips also include
significant changes over Sandy Bridge:
 F16C (16-bit Floating-point conversion instructions).
 RdRand instruction (Intel Secure Key).
 PCI Express 3.0 support (not on Core i3 and ULV
processors).
 Max CPU multiplier of 63 (57 for Sandy Bridge).
 RAM support up to 2800 MT/s in 200 MHz
increments.
 The built-in GPU has 6 or 16 execution units (EUs),
compared to Sandy Bridge's 6 or 12.
 Intel HD Graphics with DirectX 11, OpenGL 3.1, and
OpenCL 1.1 support. OpenGL 4.0 is supported with
9.18.10.3071 WHQL drivers and later drivers.
 DDR3L and Configurable TDP (cTDP) for mobile
processors.
 Multiple 4K video playback.
 Intel Quick Sync Video version 2.
 Up to three displays are supported (with some
limitations: with chipset of 7-series and using two of
them with Display Port or eDP).
 A 14- to 19-stage instruction pipeline, depending on
the micro-operation cache hit or miss.
Translation look aside buffer sizes



Cache Page Size
Name Level 4 KB 2 MB 1 GB
DTLB 1st 64 32 4
ITLB 1st 128 8 / logical core none
STLB 2nd 512 none none

C. Comparing Sandy bridge vs. Ivy Bridge
Here’s a list of the most important differences—and
similarities—between the two.

1. Sandy Bridge is last year's news. Intel introduced its
Sandy Bridge desktop and laptop processors at the start of
2011, just in time to coincide with the Consumer Electronics
Show in Las Vegas. Ivy Bridge, due to a number of delays,
arrived in April of 2012, and essentially replaced Sandy
Bridge in the market. This doesn't mean you won't still find
Sandy Bridge processors, or systems using them, for sale in
some places, but they're more or less in their end-of-life cycle
now, with the newer technologies and benefits of Ivy Bridge
having replaced them.
2. Ivy Bridge is a "tick," Sandy Bridge was a "tock." With
its Sandy Bridge chips last year, Intel introduced a new
microarchitecture that changed the building blocks of the
processor's operation. Because Ivy Bridge uses the Sandy
Bridge architecture, just about each individual change Intel
debuted before (Turbo Boost 2.0 for dynamic hands-off
overclocking, Quick Sync Video for speedier video
transcoding, and so on) also applies now. The changes this
time around are far less sweeping, with the processing die
shrink from 32nm to 22nm being the biggest news. Intel has
added some additional features as well—enough, in fact, that
for a while the company referred to this year's move as a "tick-
plus"—but this is the most fundamental.

3. 3. Ivy Bridge uses some newer technologies. In order to
achieve the reduction in Ivy Bridge die size, Intel developed a
new kind of three-dimensional "Tri-Gate" transistor. But there
are some additional advancements in Ivy Bridge, as well,
including support for PCI Express (PCIe) 3.0 and DDR3L
(low-voltage) memory, buffed-up security features, and better
integrated graphics.
4. Ivy Bridge is faster—but just a little. Performance
generally improves more between "ticks" and "tocks" than
between "tocks" and "ticks," and you can see this in the
relationship between Sandy Bridge and Ivy Bridge. In our
testing, for example, an Intel Core i7-3770K Ivy Bridge
processor earned in our CineBench R11.5 multicore rendering
test a score of 1.65, compared with a Core i7-2700K (the
fastest Sandy Bridge chip) in the same system earning 1.58.
The chips' scores in PCMark 7 (3,679 versus 3,867) and times
in Adobe Photoshop CS5 (2 minutes 47 seconds versus 2:50)
and Handbrake 0.9.6 (32 seconds versus 31 seconds) also bear
this out. So you will see speed bumps, but they'll be small this
time around. Chances are, however, that next year's "tock"
will boost the speeds of new processors considerably more.
5. Ivy Bridge uses less power. With die shrinks typically also
come a reduction in the amount of power that processor needs
to operate. That's certainly true in the case of Ivy Bridge. As
long as we were testing the Core i7-2700K and the Core i7-
3770K with otherwise exactly the same hardware setup, we
decided to take some power readings using an Extech Data
logger. Though the full systems idled at almost the same
electricity draw (about 71 watts), there was a stark difference
when we maxed out all four of the processors' cores: The Core
i7-2700K system needed 166.5 watts, but the Core i7-3700K
drew only 136.3—a remarkable change.
6. Ivy Bridge has better graphics... Sandy Bridge processors
sported a redesigned video system (available in two flavors:
Intel HD Graphics 2000 or 3000, with the latter being more
powerful), but one that was limited in a few key ways. Ivy
Bridge chips removed one of the chief limitations by replacing
Sandy Bridge's dusty DirectX 10.1 (DX10.1) support with
DX11 capabilities, and generally improving their speed and
functionality. We didn't see enormous frame rate leaps
between HD Graphics 3000 (in the Core i7-2700K) and 4000
(in the Core i7-3770K) in our testing with currently popular
3D titles, but we definitely saw some.
7. ...but still not good enough for intense gaming. But the
fact remains that, despite these changes, you'll still want a
discrete video card if you're serious about playing 3D games
like Max Payne 3, Batman: Arkham City, or The Elder Scrolls
V: Skyrim. Neither generation of Intel HD Graphics was
designed to provide outstanding frame rates in those kinds of
titles, particularly with maxed-out graphical details or at larger
resolutions, so a standalone card from either AMD or NVidia
will enhance your experience tremendously. Don't care at all
about those types of games? Then any incarnation of Intel HD
Graphics will suit you just fine.
8. Ivy Bridge and Sandy Bridge are backward-compatible.
Intel has a not-entirely-undeserved reputation of forcing
people to buy new motherboards every year or every other
year if they want to be able to use the highest-performance
CPUs available. The good news is that that's not the case with
Ivy Bridge. Sandy Bridge processors will work in Ivy Bridge
motherboards, and vice versa (although, in that case, you may
need to update your motherboard's BIOS to ensure
compatibility). You may find yourself a little constrained in
some ways by using a newer CPU in an older board, but this is
a good way to get your hands on the latest technologies
without having to perform a full-scale upgrade on your PC. It's
also a good way to reduce confusion in the market—and one
we'd be happy to see Intel adopt again in the future.

REFERENCES

[1] http://en.wikipedia.org/wiki/Sandy_Bridge
[2] http://en.wikipedia.org/wiki/Ivy_Bridge_%28microarchitecture%29
[3] http://www.pcmag.com/article2/0,2817,2405317,00.asp.