Overclocking and PC Performance Optimization for System Builders

• Performance

• Conclusion

Layout and Features

The first thing casual observers will likely notice about the P5E3 Premium is its elaborate heat-pipe cooler that wraps around the CPU socket and covers the Northbridge, Southbridge, and eight-phase voltage regulator. More experienced eyes will jump straight to the three PCI-Express x16 slots.

Like the X38 before it, the X48 supports two full-bandwidth PCI-Express 2.0 x16 slots. PCI-Express 2.0 mode offers up to twice the peak throughput of previous PCI-Express versions and is fully backwards compatible. All three x16 slots are spaced two apart to support thick graphics cards coolers, but installing a pair of cards will reduce airflow to the top cooler.

The third black x16 slot uses only x4 pathways in PCI-Express 1.1 mode, meaning it has only one-eighth the performance of the blue slots and should probably only be used for low-demand graphics applications or non-graphics expansion cards. In fact, it could be the perfect home to a high-performance x8 RAID controller, since it provides up to 1000MB/s transfer mode, bi-directionally.

Other slots include two PCI and one PCI-Express x1. ASUS left the top slot position empty on this motherboard revision, which formerly held a second PCI-Express x1 slot. Users of two double-thick graphics cards will find one PCI and the x1 slot both covered by graphics coolers, leaving only the previously-detailed black slot and top PCI slot available for additional devices.

By removing the top x1 slot from the new circuit board, ASUS is able to prevent high-end graphics card users from having access to any x1 slots. The reason for this might be because the X48 has only six unclaimed PCI-Express lanes, and two of these are routed to onboard controllers. Inserting a card into the x1 slot forces the bottom slot into x1 mode.

ASUS points its one PATA and four SATA ports towards the front edge of the motherboard, while the two remaining SATA ports point upwards. This allows cables to clear long expansion cards, but could cause some SATA cable ends to conflict with the lower drive bays of tight cases.

Along the P5E3 Premium motherboard's bottom edge is a front-panel audio connector plus serial port, an IEEE-1394 FireWire, and two 2-port USB 2.0 break-out headers. The front panel audio location is most tragic among these, as it's in the opposite corner from the front-panel jacks of many cases. In particular, we've found many Thermaltake cases with cables that simply wouldn't reach this far, but with so many motherboard manufacturers using this layout we have to put most of the blame on case designers.

Between the lower PCI and x16 slots, the ASUS Express Gate USB Flash Drive is pre-programmed with a Linux-based OS called SplashTop. We'll provide a few more details later in this article.

Table of Contents

• Introduction

• Performance

• Conclusion

Features (continued)

The WiFi-AP @n part of the P5E3 Premium's full name comes from a mini USB card located next to other rear-panel ports. Supporting 802.11b, g, and Draft N, the AzureWave AW-NA830 is labeled as an independent part though it's obviously designed for ASUS' USB port header placement.

Onboard devices include:

The WiFi card's Ralink RT2770F wireless USB adapter
JMicron JMB363 ATA-133/SATA-3.0GB/s PCI-E controller
LSI (Formerly Agere) L-FW3227 PCI IEEE-1394 FireWire controller
Realtek RTL-8110SC PCI to Gigabit Ethernet controller
Marvell 88E8056-NNC1 PCI-Express to Gigabit Ethernet controller
Analog Devices AD1988B HD audio codec

The JMicron controller provides the internal ATA-133 plus external eSATA ports at full bandwidth, while only one of the two Gigabit Ethernet ports can make the same claim. This is because both Gigabit Ethernet and PCI-Express standards are bi-directional while legacy PCI is not.

ASUS has done away with PS/2 mouse ports on recent performance boards, moving the keyboard port into its place. The P5E3 Premium rear panel provides six USB 2.0 ports, coaxial and optical digital audio outputs, two network ports, an IEEE-1394 FireWire port, two eSATA ports, six analog audio jacks, and two antenna jacks attached to the WiFi-AP @n mini USB adapter.

The ASUS retail bundle includes a motherboard manual, a WiFi users guide, two WiFi antennas, two optional heat-pipe fans, Ultra ATA and Floppy ribbon cables, a quick connector kit for simplifying front panel connections, four Serial ATA cables, a 4-pin to 2-drive "Molex" to SATA power adapter cable, a standard port shield, and a 2-port USB 2.0 plus single-port IEEE-1394 FireWire break-out plate. Included but not shown are the motherboard installation DVD and a small ASUS case badge.

ASUS Express Gate Features

The ASUS Express Gate USB drive is loaded with the SplashTop OS, with an option menu that precedes the POST screen. Users can take a quick jump from here to a web browser or Skype, shortcut the timer by clicking "Enter OS", go to BIOS by clicking "BIOS Setup", or power down. Anyone who doesn't want to see this menu can also disable the Express Gate module in BIOS.

The Express Gate module contains enough unused flash memory to store user profiles, including Skype account, language choices of English, German, French, or Chinese (simplified or traditional), screen resolutions from 800x600 to 1440x1050, networks settings, etc.

It's nice to be able to get online before loading the hard drives of a new system, but we didn't find any way to download anything to another drive. Thus, the Express Gate implementation of SplashTop OS seems rather limited to "instant access" of web-based email and instant messaging.

Table of Contents

• Introduction

• Performance

• Conclusion

BIOS and Overclocking

ASUS puts its important overclocking settings on one menu that must be scrolled through, but we captured the entire list and pasted the images together for convenience, cropping the sides rather than shrinking the image for a clear view of text.

Using a Penryn-based processor opens up the .5x multipliers for easier overclocking control. The range of key control values includes:

CPU FSB clock of 200-800MHz (FSB-800 to FSB-3200)
DRAM multipliers of 1.0, 1.2, 1.25, 1.33, 1.5, 1.60, 1.66, and 2.0 times FSB clock
PCI-Express clock of 100-180MHz
CPU Core voltage from 0.850 to 2.100 volts in 6.25 millivolt increments
FSB voltage of 1.20 to 1.50 volts in 20 millivolt increments
Memory voltage from 1.50 to 2.78 volts in 20 millivolt increments
Northbridge voltage from 1.25 top 2.21 volts in 20 millivolt increments
Memory timings of CAS 4-11, tRCD of 3-18, tRP of 3-28, and tRAS of 3-34 cycles

ASUS also includes a "Load-Line Calibration" setting which is supposed to reduce the amount of voltage fluctuation to the CPU under load. It also increases the CPU core voltage however, so users should check their voltage levels after enabling this setting.

In fact, after some fuss we found we actually had to enable the "Load-Line Calibration" feature and select the appropriate voltage values simply to reach the same stable "Highest Overclock" we'd previously seen in our Penryn-based Intel Core 2 Duo E8500.

An overclock of 4.465GHz is nothing to be ashamed of, but we were hoping to set a record with ASUS' top motherboard and X48 chipset. In fact, the last time we reached this speed we had used an older, lower-market P35 Express motherboard.

Table of Contents

• Introduction

• Performance

• Conclusion

Performance

We've kept Gigabyte's GA-P35C-DS3R around for its uncompromised support of both DDR2 and DDR3 memory, so it serves as the basis for comparing ASUS' top-end, DDR3 supporting P5E3 Premium. Also included in this review is Super Talent's stunning DDR3-1600, which we operated at 1333 MHz using CAS 6-5-5-12.

Testing System Configuration
Motherboard	ASUS P5E3 Premium/WiFi-AP @n Gigabyte GA-P35C-DS3R
Processor	Intel Core 2 Duo E8500 3.13GHz
Video Card	MSI NX8800GTS OC 512MB
RAM	Super Talent DDR3-1600 CAS7
Hard Drive	Samsung Spinpoint T166 500GB
Optical	NEC ND-3500A DVD+/- R/RW
PSU	Ultra X3 1000W
OS	Windows XP Service Pack 2
Drivers	Motherboard driver pack NVIDIA Forceware 169.21 Graphics

We'll start with Sandra 2005's Arithmetic test, which should show similar performance for boards that don't cheat by cranking up clock speed.

With no noticeable performance difference in CPU performance, let's retest with Sandra's multimedia test.

Again, everything looks legitimate. Now let's move on to some DirectX testing.

Our G92-based 8800GTS 512 gains nothing from the P5E3 Premium's PCI-Express 2.0 capabilities, but it's likely that graphics technology simply hasn't caught-up yet. Still, we'll check out the OpenGL performance testing.

Other than a few unexplained minor losses for the newer-technology motherboard, we don't see any significant performance difference due to chipset technology.

Table of Contents

• Introduction