Intel DP55KG - Desktop Board Extreme Series... Quick start guide

Intel® Desktop Board DP55KG and
Intel® Desktop Board DP55SB
Extreme Series
Performance Tuning Guide
Revision 1.4
October, 2009
Part Number: E78969-002

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
2
INFORMATION IN THIS DOCUMENT IS PROVIDED IN CONNECTION WITH INTEL®PRODUCTS. NO LICENSE, EXPRESS OR IMPLIED, BY
ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANTED BY THIS DOCUMENT. EXCEPT AS PROVIDED IN
INTEL'S TERMS AND CONDITIONS OF SALE FOR SUCH PRODUCTS, INTEL ASSUMES NO LIABILITY WHATSOEVER AND INTEL DISCLAIMS
ANY EXPRESS OR IMPLIED WARRANTY, RELATING TO SALE AND/OR USE OF INTEL PRODUCTS INCLUDING LIABILITY OR WARRANTIES
RELATING TO FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER
INTELLECTUAL PROPERTY RIGHT.
UNLESS OTHERWISE AGREED IN WRITING BY INTEL, THE INTEL PRODUCTS ARE NOT DESIGNED NOR INTENDED FOR ANY
APPLICATION IN WHICH THE FAILURE OF THE INTEL PRODUCT COULD CREATE A SITUATION WHERE PERSONAL INJURY OR DEATH MAY
OCCUR.
Intel may make changes to specifications and product descriptions at any time, without notice. Designers must not rely on the absence
or characteristics of any features or instructions marked "reserved" or "undefined." Intel reserves these for future definition and shall
have no responsibility whatsoever for conflicts or incompatibilities arising from future changes to them. The information here is subject
to change without notice. Do not finalize a design with this information.
The products described in this document may contain design defects or errors known as errata which may cause the product to deviate
from published specifications. Current characterized errata are available on request.
Intel®Turbo Boost Technology requires a PC with a processor with Intel Turbo Boost Technology capability. Intel Turbo Boost Technology
performance varies depending on hardware, software and overall system configuration. Check with your PC manufacturer on whether
your system delivers Intel Turbo Boost Technology. For more information, see
http://www.intel.com/technology/turboboost.
Warning: Altering PC memory frequency and/or voltage may (i) reduce system stability and use life of the system,
memory and processor; (ii) cause the processor and other system components to fail; (iii) cause reductions in system
performance; (iv) cause additional heat or other damage; and (v) affect system data integrity. Intel assumes no
responsibility that the memory, included if used with altered clock frequencies and/or voltages, will be fit for any
particular purpose. Check with memory manufacturer for warranty and additional details.
Warning: Altering clock frequency and/or voltage may (i) reduce system stability and useful life of the system and
processor; (ii) cause the processor and other system components to fail; (iii) cause reductions in system performance; (iv)
cause additional heat or other damage; and (v) affect system data integrity. Intel has not tested, and does not warranty,
the operation of the processor beyond its specifications.
Intel, the Intel logo, and Intel Core are trademarks of Intel Corporation in the US and other countries.
*Other names and brands may be claimed as the property of others.
Copyright © 2009, Intel Corporation. All rights reserved.

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
3
Contents
1. Introduction 5
1.1. Intel®Desktop Control Center.............................................................5
2. Intel®Core™ i7 and Intel®Core i5™ Processors and Intel®P55
Express Chipset General Concepts 6
2.1. Architecture...................................................................................... 6
3. Intel Desktop Board DP55KG/DP55SB BIOS Setup 8
3.1. Accessing BIOS Setup........................................................................8
3.2. Recovering from an Unstable System ................................................... 8
3.3. Preparing Setup Options (Optional)......................................................9
4. Optimizing Processor Performance 11
4.1. Processor Performance Tuning Options............................................... 12
4.2. Processor Tuning Process: The Host Clock Method............................... 15
4.3. Confirming System Stability.............................................................. 16
4.4. How to Measure Processor Core Frequency ......................................... 17
5. Memory Optimization 18
5.1. Optimizing Memory Performance ....................................................... 18
5.2. Memory Performance Options............................................................ 19
5.3. Determining Memory Frequency ........................................................ 21
5.4. Using XMP Profiles........................................................................... 22
5.5. XMP Manual Mode ........................................................................... 23
6. Examples of Over-Clocked Settings 24
6.1. Using the Host Clock for Performance Boost ........................................ 24

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
4
Figures
1. Intel Desktop Control Center...............................................................5
2. Intel Desktop Board DP55KG/DP55SB Block Diagram ............................. 7
3. System Setup with Features Disabled (Optional).................................... 9
4. System Power with CPU C States Disabled (Optional) ........................... 10
5. Performance Tuning Disclaimer ......................................................... 11
6. Performance Tuning Main Page.......................................................... 12
7. Processor Overrides Page ................................................................. 13
8. Increasing the Host Clock Frequency.................................................. 15
9. Confirming System Levels with Intel Desktop Control Center ................. 17
10. Memory Configuration...................................................................... 19
11. Selecting XMP Profiles...................................................................... 22
12. Checking the Uncore Voltage Override................................................ 23
13. System Overclocked to 3.67 GHz from 2.93 GHz with Turbo Disabled ..... 24
14. System Overclocked with Default Processor Overrides .......................... 25
15. Bus Overrides at Default................................................................... 26
16. Memory Configuration with Uncore Voltage Adjusted in Manual Mode...... 27
17. Memory Performance Increased to 2305 MHz ...................................... 28
18. Watchdog Timer Tripped .................................................................. 29
Tables
1. Processor Overrides......................................................................... 14
2. Performance Memory Profiles............................................................ 20
3. Memory Multipliers .......................................................................... 21

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
5
1. Introduction
Performance tuning on Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB can be
a simple and straightforward process, providing useful gains in overall system performance.
This guide describes ways to increase system performance by tuning the various subsystems of
the desktop board. The main focus areas include the Intel®Core™ i7-800 and Intel®Core™
i5-700 processor series, the memory subsystem, and the data interlinks connecting the various
desktop board components. The procedures and examples in this document are for reference
only and are not guaranteed to work in all situations and system configurations.
Please note that operating desktop board components beyond their nominal values adds
additional thermal stress to the overall system and additional cooling may be required to ensure
stable system operation.
It is also important to note that over-clocking any desktop board can create additional electrical
and thermal stress on the components and can reduce the system’s overall useful lifespan.
Consequently, over-clocking on an Intel®Desktop Board Extreme Series is not covered under
the standard warranty.
Performance tuning is not an exact science; system stability is highly dependent upon overall
system construction and will vary with each system configuration.
During the lifetime of the board the BIOS may be updated with additional features and
improvements like the look and feel.
1.1. Intel®Desktop Control Center
The Intel®Desktop Control Center is a great tool for monitoring most Intel Desktop Board
Extreme Series-based systems and is available for download at http://www.intel.com/go/dcc.
New to Intel Desktop Board DP55KG/DP55SB is the easy auto tune capability. Beyond the
scope of this guide, the Intel Desktop Control Center (Figure 1) is another resource for
performance tuning.
Figure 1. Intel Desktop Control Center

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
6
2. Intel®Core™ i7 and Intel®Core i5™
Processors and Intel®P55 Express Chipset
General Concepts
2.1. Architecture
The Intel Desktop Board DP55KG/DP55SB platform consists of an IntelCore i7-800 or
Intel Core i5-700 processor series and the Intel®P55 Express Chipset component—the Intel®
P55 Platform Controller Hub (PCH). For a detailed description of the complete platform, refer to
the Intel Desktop Board DP55KG Technical Product Specification or the Intel Desktop Board
DP55SB Technical Product Specification available at
http://www.intel.com/products/desktop/motherboard.
The processor now integrates the system memory controller and accesses DDR3 memory
through two independent memory channels. The processor also provides support for one full
PCI Express* 2.0 x16 graphics slot or switches to two PCI Express 2.0 x8 slots. The processor
connects to the PCH via the Direct Media Interface (DMI) interconnect bus. The PCH provides
support for SATA (3.0 Gb/s), USB 2.0, and other system interfaces. Figure 2 shows a block
diagram of the Intel Desktop Board DP55KG/DP55SB platform.

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
7
Intel Core i7
or Intel Core i5
Processor
PCH
Clock Generator DDR3 Dual
Channel
PCIe x16 / x8
PCI Express BusDMI BUS
133 MHz
PCIe x8
USB 2.0
SATA
DIMM 1 Channel A DIMM 0 Channel A DIMM 1 Channel B DIMM 0 Channel B
100 MHz
100 MHz
Figure 2. Intel Desktop Board DP55KG/DP55SB Block Diagram
All desktop board components are driven from a single 133 MHz host clock (BCLK). The
resulting processor frequency is generated by applying a multiplier value to the host clock
(BCLK).

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
8
There are three frequency multipliers on these desktop boards. All frequencies are tied to the
host clock (BCLK) which is used to develop the overall system speed. The multipliers are as
follows:
1. Processor: The processor frequency is developed when the system host clock frequency
(default 133 MHz) is multiplied by the Processor Multiplier. The Processor Multiplier
automatically adjusts higher with Turbo Mode or lower with EIST.
2. Memory: The memory frequency is developed when the Memory Multiplier is multiplied by
the system host clock frequency. For example, a Memory Multiplier of 10 ×133 MHz host
clock results in a memory frequency of 1333 MHz.
3. Uncore: Applies to the non-core related items in the processor, such as the cache
controller, memory controller, and the data and address buffers. The Uncore Multiplier is
locked by the processor at 18 for an Intel Core i7-870 processor for example. The Uncore
Multiplier is unlocked on Intel Core i7-900 series Extreme Edition processors for example.
3. Intel Desktop Board DP55KG/DP55SB
BIOS Setup
This section describes examples of modifying system controls and the performance tuning
options that are available to enhance desktop board performance.
3.1. Accessing BIOS Setup
The BIOS setup screen can be accessed at system startup by pressing the F2 key at the setup
screen prompt. It is advised to run the latest BIOS version to ensure that performance features
are at the highest level of optimization. The latest version BIOS can be obtained from
http://downloadcenter.intel.com.
Before starting any performance tuning, be sure that the BIOS setup defaults have been
applied by pressing the F9 key while in BIOS setup mode. Press the F10 key to save the
settings once the BIOS changes have been made.
3.2. Recovering from an Unstable System
Should performance values be set beyond the point of stable system operation, there are three
options for recovery:
1. Third-Generation Watchdog Timer
2. Back-to-BIOS button
3. BIOS configuration jumper
A third-generation hardware Watchdog Timer has been included as part of the desktop board
circuitry. This timer is enabled by default in the BIOS and will automatically boot to BIOS with
a safe set of performance values whenever it detects unstable system operation or if the board
hangs during start up.
If the Watchdog Timer fails to automatically reboot the board, the Back-to-BIOS button located
on the back panel can be depressed to cause the board to boot into the Back-to-BIOS screen
with default BIOS settings invoked while maintaining all of the user’s BIOS settings shown to
allow for easy recovery.
In addition, the BIOS configuration jumper is provided on the board to force the board to boot
in a safe mode making it possible to reset the BIOS to default settings and restore the board to
functionality. Refer to the desktop board product guide for instructions on using the jumper for
resetting purposes.

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
9
3.3. Preparing Setup Options (Optional)
It is recommended to disable non-essential interfaces (such as, onboard audio, USB, LAN,
external SATA, etc.) when tuning to get a clean and basic system as a starting point for
performance tuning. Once the performance variables have been optimized, the other onboard
features can then be re-enabled as needed.
Scroll to “Configuration” and use the submenu to disable these features (Figure 3).
Figure 3. System Setup with Features Disabled (Optional)

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
10
Figure 4 shows the System Power submenu with the CPU C states disabled for example.
Note: 1-, 2-, and 3-Core Turbo modes require CPU C-states. Disabling C-states will limit Core
Turbo to only the 4-Core ratio. For example, an Intel Core i7-870 processor with a 4-Core
Turbo ratio results in a maximum frequency of only 3.2 GHz.
Figure 4. System Power with CPU C States Disabled (Optional)

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
11
4. Optimizing Processor Performance
Performance tuning options are located in a menu section labeled “Performance.” Read and
agree to the disclaimer (Figure 5). Please note that any performance increase achieved is
dependent on the Processor, memory and motherboard used. All of these parts of the system
have inherent variability and one or more will limit the overall systems ultimate top
performance.
Figure 5. Performance Tuning Disclaimer

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
12
4.1. Processor Performance Tuning Options
The main Performance Tuning page is shown in Figure 6 with an Intel Core i7-870 processor
installed.
Figure 6. Performance Tuning Main Page

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
13
CPU tuning options are listed under “Processor Overrides” as shown in Figure 7. Refer to
Table 1 for descriptions of the Processor Overrides.
Figure 7. Processor Overrides Page

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
14
Table 1. Processor Overrides
Setup Option Description
CPU Voltage Override Options
Static CPU Voltage
Override Overrides the voltage requested by the processor and applies a static voltage. This option disables
the dynamic voltage control of the processor.
Dynamic CPU Voltage
Offset (mV) Maintains the dynamic VID control of the processor which scales the output voltage around
the selected base voltage automatically.
CPU Vreg Droop Control Changes the amount of voltage drop applied when
the processor draws maximum current. Choosing
the “Low V-droop” option causes the desktop
board to supply voltage with no drop even at
maximum processor current draw.
Processor Performance Options
Note: All multiplier values listed below are applied to the single 133 MHz Host
clock.
Maximum Non-Turbo Ratio Sets the default multiplier that the processor will
use. Useful when increasing the host clock
frequency above 133 MHz. The maximum
multiplier is dependent on the processor installed.
CPU Idle State Enables CPU low power states. High performance
mode will always run the CPU at the chosen
multiplier. Low power mode allows EIST to
function.
Turbo Mode Override Options
TDC Current Limit
Overrride (Amps)
TDP Power Limit Override
(Watts)
Displays the default current limit and the
processor rated TDP.
Turbo Mode Multipliers
4-Core Ratio Limit
3-Core Ratio Limit
2-Core Ratio Limit
1-Core Ratio Limit
Display’s Maximum CPU performance given
adequate thermal margin, voltage, and current
applied while not in C3 or C6 power states.

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
15
4.2. Processor Tuning Process: The Host Clock
Method
The frequency of the CPU can be set by increasing the host clock and leaving the multipliers
unchanged.
From the Performance page set the “Host Clock Frequency Override” setting to “Manual”.
Next, increase the Host Clock Frequency (MHz) to a desired level.
Figure 8. Increasing the Host Clock Frequency
In Figure 8, the column labeled “Proposed” shows the results of setting the host clock to
148 MHz which will result in a processor speed of 4.00 GHz with Turbo mode set to default
27 multiplier with Turbo Boost enabled. Additional voltage may need to be applied to the
processor to ensure stable performance at 4.00 GHz.
Note: The multipliers for the processor were left unchanged and only the host clock frequency
(BCLK) was increased. Since the frequency of the other board subsystems is derived from the
base clock, the memory speed will be increased as well, this can be seen in Figure 8 as
1186 MHz memory frequency.
This increase may affect system stability, and, therefore, memory timings and voltage
adjustments in the BIOS memory section might be necessary for system stability.
Refer to Section 5 for more information on memory settings.

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
16
4.3. Confirming System Stability
Once the selections are made, it is time to confirm the selected frequency and gauge system
stability:
1. Save changes using the F10 key and boot into the operating system.
2. Next force the operating system to request that the processor operate in P0. P0 is the
highest performance state. To do so, in Windows* XP, select the “Always On” profile. In
Windows Vista* or Windows* 7 use the “Performance” profile, in the Power Settings Control
Panel applet.
3. When processor cores are idle, the Intel Core i7-800 and Intel Core i5-700 processor series
will operate at a reduced multiplier value. By applying a heavy load to the processor in the
operating system all processor cores will be out of the idle state and run at the multiplier
values chosen in the BIOS setup. Heavy loads can be applied by using any common
processor benchmarking software.
Note: If the settings have been set too aggressively and the board becomes unstable, refer to
Section 3.2 for recovery options.
Other software tools to test stability are:
Orthos (http://sp2004.fre3.com/beta/beta2.htm)
3DMark* Vantage (http://www.futuremark.com/benchmarks/3dmarkvantage/introduction/)
Loading the processor will also serve to test the stability of the system. Prime95*, Super PI*,
or similar software can be used to load the processor.

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
17
4.4. How to Measure Processor Core Frequency
Use a processor frequency display tool to verify the final speed. The Intel Desktop Control
Center will have details on processor frequency and system speeds as shown in Figure 9.
Figure 9. Confirming System Levels with Intel Desktop Control Center
Third party tools are also available like CPUID CPU-Z* or CPUID TMonitor* to monitor processor
speed.
Once the desired frequency and system stability have been confirmed, the other subsystems
can be optimized.

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
18
5. Memory Optimization
5.1. Optimizing Memory Performance
A wide variety of memory timing parameters can be adjusted in the BIOS setup.
Although each memory parameter can be modified individually, the easiest method of
optimizing memory performance is to use memory that supports XMP profiles. These profiles
are pre-programmed by the memory module manufacturer in the memory module itself and
can be selected through the BIOS Memory Configuration. These profiles are validated by the
manufacturer and are optimized for both performance and system stability.
The BIOS is designed to use the XMP memory profiles as a starting point for extending memory
performance by more sophisticated system tweakers by then taking manual control after
selecting an XMP profile.
In addition, memory population will also affect system performance. The Intel Core i7-800 and
Intel Core i5-700 processor series have two independent memory channels. On Intel Desktop
Board DP55KG/DP55SB, these are indicated by the two blue memory sockets. For best
performance, populate the DIMM 0 of each channel, signified by the color blue with memory
matched by manufacturer, size, speed, and type first. This matching allows the processor to
access data across each of the memory channels by interleaving. Interleaving greatly reduces
the latencies of waiting for memory to return data.
The two black memory connectors allow the end user to double the board’s system memory
capacity. Higher total memory capacity can have a positive benefit in very data-intensive
applications. Always populate the blue memory sockets first for best system performance.

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
19
5.2. Memory Performance Options
The Memory Configuration page (Figure 10) contains all the memory timing options that can be
adjusted and Table 2 describes the Performance Memory Profiles.
Figure 10. Memory Configuration

Intel®Desktop Board DP55KG and Intel®Desktop Board DP55SB Extreme Series
Performance Tuning Guide
20
Table 2. Performance Memory Profiles
Setup Option Description
Memory Performance Options
Note: All multiplier values listed below are applied to the single 133 MHz
(default) host clock.
Performance Memory
Profiles Automatic setting uses default values provided by the memory module.
Manual mode allows the user to change each of the
settings.
If the installed memory module supports XMP, there
will be additional selections for each profile stored in
the module. Selecting a profile will populate all the
settings with those recommended by the
manufacturer.
Uncore Multiplier Sets the Uncore CPU multiplier. This is
non-adjustable for Intel Core i7 and Intel Core i5
processors. It is shown for information purposes.
Memory Multiplier Sets the memory multiplier provided by the on die
memory controller of the installed processor.
tCL CAS Latency: The amount of time in cycles between
sending a read command and the time to act on it.
tRCD RAS to CAS Delay: The amount of time in cycles for
issuing an active command and the read/write
commands.
tRP RAS Precharge Time: This is the minimum time
between active commands and the read/writes of the
next bank on the memory module.
tRASmin Minimum RAS Active Time: The amount of time
between a row being activated by precharge and
deactivated.
tRFC RAS Refresh Cycle Timing: This determines the
amount of cycles to refresh a row on a memory bank.
tRRD RAS to RAS Delay: The amount of cycles that it
takes to activate the next bank of memory.
tWR Write Recover Time: The amount of cycles that are
required after a valid write operation and precharge.
tWTR Write to Read Delay: The amount of cycles required
between a valid write command and the next read
command.
tRTP Read to Precharge Delay: The minimum delay prior
to when a Read can occur.