ASUS P5Q Pro Mainboard Review

We have just tested one more mainboard on Intel P45 Express. This time it is a mainstream solution from ASUS supporting DDR2 SDRAM. Its specifications make it a potential hit, but how good this mainboard actually is? Let’s find out!

by Ilya Gavrichenkov
09/10/2008 | 07:28 PM

There haven’t been many reviews on our site lately that were dedicated to solutions based on Intel’s latest offering for LGA775 platform – Intel P45 Express chipset. And there was a good reason for that. The thing is that our first experience with mainboards based on the today’s most advanced chipset wasn’t that successful at all. Those few mainboards that we checked out didn’t reach any new performance heights and didn’t help us achieve any new overclocking records. Moreover, the solutions from ASUS, MSI and Gigabyte that we have already discussed seemed a little raw, had a few bugs in the BIOS and actual hardware thus making not the most favorable impression.


Hopefully the situation has changed by now. Intel P45 Express based mainboards should be getting more mature BIOS versions free from early-stage problems and using the potential of the new chipset to the full extent. So, it seems to be the right time to resume testing these products.

We picked ASUS P5Q Pro for our new round of experiments. It is not a top product, but a solution from mainstream price segment supporting DDR2 SDRAM and featuring two PCI Express x16 slots. We believe reviewing top high-end solutions may not make that much sense any more. Those computer enthusiasts who strive for maximum performance will hardly be satisfied with an LGA775 system on Core 2 Duo or Core 2 Quad processors at this time. They are anxiously awaiting the new Core i7 processors that should be announced within the next few weeks. As for Intel P45 Express based boards, they should be of primary interest to those users who need not just speed, but the optimal combination of speed and price. This is where ASUS P5Q Pro looks pretty promising. It boasts great functionality, but is not overloaded with features. Moreover, ASUS marketing team seems to have decided not to focus their efforts on P5Q Pro, so it doesn’t have any useless “decorative” additions.

In other words, if ASUS P5Q Pro also works the way all high-quality solutions with ASUS logo should, then it has every chance to get our best recommendations. So, our today’s review will be devoted to checking out how good ASUS P5Q Pro mainboard is in real life.


According to official ASUS site, this company is currently offering 11 different mainboards based on Intel P45 Express chipset. P5Q Pro we are talking out today is somewhere in the middle of this list: on the one hand it uses high-quality components, just like the most expensive solutions in the family, but on the other – it doesn’t have the excessively sophisticated 16-phase processor voltage regulator.

The mainboard looks quite ordinary: no luxuriously twisted heatpipes or humongous heatsinks. Just a common looking board.

Nevertheless, this solution has a pretty long list of features. The thing is that the entire series of ASUS mainboards based on Intel P45 Express support a number of very interesting technologies mentioned in this list. I would like to specifically point out three of them right away, because they are the primary focus of the manufacturer’s marketing efforts:

Moreover, there is one more thing about this board that catches your attention. ASUS promises that P5Q Pro, just like all other mainboards from this series, supports CPUs with 1600MHz bus that are not officially supported by Intel P45 Express chipset. As a result, ASUS makes this overclocking potential of its mainboard semi-official promising its reliable operation in this mode.

Package and Accessories

The box of ASUS P5Q Pro is pretty ordinary. It is of standard size, without any windows or flip-open covers that have become a common feature of many contemporary products. The only thing that distinguishes ASUS P5Q Pro package is a glossy finish and deep blue-purple colors of the design. The box bears the logos and brief description of the technologies the manufacturer is especially proud of. There is also a small photo of the actual board.


Inside the box there is a pretty standard set of accessories for a mainstream mainboard that includes a user’s manual, a DVD-disk with drivers and software, I/O Shield for the case rear panel and a set of cables for different storage devices. Besides, ASUS also included a Q-Connector block and a rear panel bracket with a 4-pin IEEE1394 connector and eSATA port.

We could have considered this bundle to be quite sufficient if it hadn’t been for the missing centrifugal fan for the mainboard cooling system. The chipset and processor voltage regulator circuitry may heat up a lot during overclocking and we seriously doubt the cooling efficiency of ASUS P5Q Pro’s default cooling system in passive mode. Especially since more expensive mainboards from the P5Q series with a more advanced cooling system all come bundled with this fan.

Mainboard Functionality

ASUS P5Q Pro is a typical Intel P45 Express based mainboard. It doesn’t surprise us with its PCB layout or unique functionality. According to the chipset specification, it features 4 DDR2 DIMM slots paired according to the supported channel and two PCI Express x16 2.0 slots working as x8 + x8 in a CrossFire configuration. Besides, the board offers two traditional PCI slots and three PCI Express x1 slots.

The chipset delivers support for 6 SATA ports at 3Gbps. Two more ports are provided by Silicon Image SiI5723 supporting Drive Xpert technology. The only PATA-133 interface is implemented via an additional Marvell 88SE6111 controller.

The chipset also provides support for 12 USB 2.0 ports - six of them are laid out on the connector panel. However, ICH10R used on ASUS P5Q Pro as a South Bridge doesn’t support IEEE1394 ports. Therefore, there is an additional dual-port Firewire controller – LSI L-FW3227.

Add-on chips also provide Gigabit network connector (Atheros AR8121) and 8-channel integrated sound tract (Realtek ALC1200). Both these chips are pretty interesting. Atheros AR8121 is the smallest PCI Express Gigabit network controller, while Realtek ALC1200 codec is manufactured specifically for ASUS. ASUS has finally decided to replace the sound solutions from Analog Devices they have used all along with more popular Realtek codecs. However, since it is a pretty exclusive solution, we couldn’t find any technical details about it. Instead we can offer you the test results for this codec in 16bit 44kHz mode:

Since ASUS P5Q Pro has no unique functions, its connector panel is pretty common too. There are six USB 2.0 ports, six analogue audio-jacks, coaxial SPDIF Out, Gigabit network port, 6-pin IEEE1394 connector and PS/2 connectors for keyboard and mouse.

Another IEEE1394 connector, 6 USB 2.0 ports and a serial COM-port are laid out as pin-connectors on the PCB.

The processor, memory and chipset voltage regulator circuitry is laid out pretty commonly, too. While top P5Q mainboards use a 16-phase CPU voltage regulator and triple-phase voltage regulators for the memory and MCH, our today’s hero P5Q Pro is designed in a much simpler way. The processor voltage regulator has 8 phases, while the memory and chipset North Bridge use dual-phase regulators. However, this limitation didn’t touch upon the quality of the components. Just like expensive ASUS boards, ASUS P5Q Pro uses solid-state Japanese capacitors with polymer electrolyte and high-frequency Low RDS(on) MOSFET.

Of course, the brand name ASUS EPU (Energy Processing Unit) chip is also there. It switches the processor voltage regulator circuitry into dual-phase mode upon a signal from the corresponding managing utility. Therefore the board is bundled with ASUS Six Engine utility, which is also responsible for switching the processor voltage regulator into a more economical mode under low workload.

However, unfortunately, this utility doesn’t do its job too well. Namely, it doesn’t work if the CPU is overclocked.

The chipset cooling system consists of two parts. There is a simple low-profile aluminum heatsink on the chipset South Bridge:

The heatsink on the chipset North Bridge is taller and is connected via a heatpipe to another aluminum heatsink covering some of the CPU voltage regulator MOSFET. However, since the voltage regulator doesn’t heat up that much during work, this heatsink may be regarded as part of the chipset North Bridge cooling system.

In fact, this cooling would be sufficient only when the board works close to its nominal mode, when the MCH voltage remains default. Any overclocking experiments on ASUS P5Q Pro require improving the North Bridge cooling by at least adding a fan to it.

This simple cooling system design has in fact a few advantages: the mainboard has enough room for any type of processor cooler. However, I have to stress that there are a few standing out contacts on the reverse side of the PCB right beneath the processor socket, which may cause certain problems if the CPU cooler requires a backplate.

Well, other than those few drawbacks pointed out above, ASUS P5Q Pro boasts very decent PCB layout.

The biggest issue is actually the location of the SATA connectors that might be hard to reach if the second graphics card in the PCI Express x16 slot is long. However, I believe very few people will actually suffer from this drawback.


During our discussion of the mainboard design and its features we have already mentioned several times that it is pretty ordinary that is why it belongs to the mainstream price segment. However, it doesn’t mean that ASUS P5Q Pro will not suit for computer enthusiasts. It is not surprising that hardware manufacturers stuff their high-end solutions with all sorts of useless extras trying to drive hardcore computer users’ attention to their most expensive products. However, experienced overclockers will not let these marketing tricks mislead them and very often go for much less pricy solutions.

This is the case with ASUS P5Q Pro. The board is not so “loaded” like ASUS P5Q3 Deluxe, for instance, however, it offers all the necessary BIOS functionality for successful CPU overclocking. Moreover, another proof that P5Q Pro has been recognized by the overclocking community is existence of numerous alternative BIOS versions improved and enhanced by the board owners independently. For example, here you can download unofficial BIOS versions with extended support for new processors and improved memory stability.

We picked a BIOS version like that for our tests of ASUS P5Q Pro. It was modified BIOS version 1104 created by Kentxxx. Note that this BIOS version seems to have no visual differences from the official one that is why everything we will say about it in our review may also refer to the official BIOS version 1104.

ASUS P5Q Pro BIOS is based on AMI micro-code and has traditional Setup interface. Most settings dealing with the system performance are gathered in Ai Tweaker section:

There are options for manual adjustment of the processor clock frequency multiplier and FSB frequency that can vary from 200MHz to 800MHz. Then you can adjust PCI Express bus frequency in the interval from 100MHz to 180MHz. the memory frequency is not so flexible, because Intel P45 Express chipset sued for ASUS P5Q Pro clocks the memory using FSB-related dividers. The list of supported dividers is the same for all latest Intel chipsets and depends on FSB Strap that can also be adjusted in the BIOS Setup. Note that the FSB Strap setting also affects the mainboard stability when we overclock by raising the FSB frequency. Overclocking is evidently most successful when FSB Strap is set at 333MHz or 400MHz, the former setting being preferable from our experience.

The ASUS P5Q Pro BIOS offers extensive list of settings for memory timings configuring. However, the Command Rate option is still missing. Instead there is a new option called Mem. Oc Charger. When activated it changes the mainboard settings to ensure best memory overclocking result. However, do not expect any wonders: insignificant improvement from enabling this parameter can only be seen on selected memory modules, while in majority of cases it will even worse the overall system stability.

I would like to pay special attention to a modified Transaction Booster option. Now it allows adjusting directly the most important North Bridge setting called Performance Level.

The options for voltage adjustment also look good:

The corresponding part of the section includes the following settings:


Supported range

CPU Voltage

0.85V - 2.1V with 0.00625V increment

CPU PLL Voltage

1.5V – 2.78V with 0.02V increment

FSB Termination Voltage

1.1V – 1.9V with 0.02V increment

DRAM Voltage

1.8V – 3.08V with 0.02V increment

NB Core Voltage

1.1V – 2.2V with 0.02V increment

SB Core Voltage

1.1V – 1. with 0.1V increment


1.5V – 1.8V В with 0.1V increment

Note that you can only get access to extremely high CPU core and North Bridge voltage settings only once you reset OV_CPU and OV_NB jumpers on the board.

All voltages may be set to Auto, in this case the board will try find the most optimal parameters for the current processor and memory frequency settings. In other words, by setting Auto you allow the board to increase the voltage on its own if the FSB or memory frequency increase beyond their nominal values. This is great help for inexperienced overclockers. However, if you are into more serious things, then manual adjustment is the way to go. Especially since the board tends to set higher values.

Among the voltage settings I would also like to point out an extremely useful option called Loadline Calibration. Thanks to the special design of the processor voltage regulator circuitry, it minimizes Vdroop effect during overclocking.

However, you will not be able to change CPU GTL Voltage Reference independently for the physical processor cores of quad-core CPUs: only top ASUS P5Q solutions support this option.

Well, let’s take a quick look at the remaining pages of the ASUS P5Q Pro BIOS Setup. Advanced section allows configuring chipset parameters, enabling and disabling integrated controllers and USB ports, and managing processor technologies.

Power section as usual has a hardware monitoring sub-section.

Boot page allows setting the order of boot-up devices and set the startup options.

Tools section contains ASUS” traditional utilities: EZ Flash 2 for reflashing the BIOS and O.C. Profile for saving settings profiles. There are also management options for Drive Xpert and Express gate technologies.

Testbed Configuration

For our practical experiments we put together the following testbed:

All tests were performed in Windows Vista Ultimate x86 SP1 operating system.


First of all we decided to check how well this board overclocks processors. The Intel P45 Express based solutions we tested before coped well with dual-core processors overclocking, but couldn’t succeed when it came to overclocking a quad-core CPU from Core 2 Quad or Core 2 Extreme family. Therefore, we performed a few experiments with different CPUs on our ASUS P5Q Pro trying to reach maximum FSB frequencies.

First of all we installed a Core 2 Dup E8600 processor – a new CPU with a more overclockable E0 processor stepping. Its nominal frequency is 3.33GHz and the multiplier is set at 10x. We managed to reach 4.4GHz with the same multiplier and increased to 1.4V processor Vcore: we only had to push FSB frequency to 440MHz.

Note that all voltages except processor Vcore were left at their defaults. In other words, Core 2 Duo E8600 overclocking on ASUS P5Q Pro required minimal efforts on our part. The system was absolutely stable, according to the Prime95 test and a 1-hour OCCT Perestroika run.

We continued pursuing our goal and undertook another experiment with the same processor but with the multiplier lowered to 8x. Of course, FSB needed to be increased much more dramatically in this case, so finer overclocking techniques had to be applied. The problem here could be increasing the chipset North Bridge voltage, because the chipset cooling system of ASUS P5Q Pro may fail to cope with a much hotter chip. Even replacing the original thermal interface with a more efficient organic silicon thermal compound didn’t help us push the NB voltage over 1.32V. As a result, we couldn’t reach stability at FSB speeds beyond 540MHz. Further MCH voltage increase resulted into chip overheating.

In other words, we achieved the same results with the multiplier lowered to 8x as we did with 10x. The CPU overclocked only to 4.32GHz, which is, actually, pretty good, too.

Note that we had not only to increase the CPU Vcore, but also other voltages to make sure that the processor remains stable at 540MHz FSB. CPU PLL Voltage was set at 1.56V, FSB Termination Voltage was increased to 1.28V. It is important to keep in mind that this FSB frequency is far not the maximum for ASUS P5Q Pro: it is the maximum its default cooling system can handle. Replacing the cooling system with something more efficient will reveal the true overclocking potential of this board and ensure stably system operation at higher FSB speeds.

This result allowed us to check ASUS stability with aggressive memory timings. In above described conditions the memory worked at 1800MHz with 4-4-4-12 timings. Of course, we increased Vdimm to 2.3V.

We have already seen multiple times that Intel P45 Express based mainboards can very well overclock dual-core processors. However, things are not so good when it comes to quad-core processors. ASUS P5Q Pro once again proved that this is indeed the case.

To be more exact, we decided to find out the maximum FSB frequency at which ASUS P5Q Pro can ensure stable work of a quad-core Intel Core 2 Extreme QX9650 processor. We reduced the CPU multiplier to 8x and set CPU PLL Voltage and FSB Termination Voltage at the maximum safe values of 1.7V and 1.35V respectively.

With these settings our processor remained stable at 453MHz FSB.

Of course, this is not the maximum for our processor, however, we couldn’t do any better than that even with significantly higher CPU PLL Voltage and FSB Termination Voltage settings, which would normally have a significant influence on the quad-core CPU overclocking. Even when we increased FSB Termination Voltage to 1.5V, we got stuck at FSB frequencies slightly over 460MHz.

In other words, ASUS P5Q Pro is far not the best platform for quad-core processors overclocking. Solutions on Intel X48 Express seem to be much better cut for this.

Here I would like to add that during our experiments we have once again detected incorrect mainboard behavior in case of over-overclocking. Just like ASUS P5Q3 Deluxe we tested earlier, if P5Q Pro can’t boot with the settings your chose, it will not reboot in safe mode and offer to correct the faulty settings. Instead it will clear CMOS completely and you will have to reconfigure everything all over again in the BIOS Setup.

Performance during Overclocking

Running performance tests on Intel P45 Express based mainboards is a not very exciting task, because Intel uses the same memory controller for its last generation chipsets as in the previous solutions. Therefore, P45 based mainboards perform almost the same as their predecessors. The support of PCI Express 2.0 does increase theoretical bandwidth of the graphics bus, but in reality affects the system performance only with two graphics cards working in Crossfire mode, so most users do not really care about it.

Does it mean that we can skip testing the performance of our ASUS P5Q Pro? Not at all. Not only chipset peculiarities affect the mainboard performance, but also BIOS optimizations. And the performance differences between the boards running different BIOS versions will primarily be seen during overclocking. That is why we decided to check how fast ASUS P5Q Pro will be compared wit the previous generation Intel P35 Express based mainboards in overclocked mode.

I have to explain that the idea of this comparison didn’t just come to mind out of the blue. The thing is that ASUS P5Q Pro BIOS Setup does in fact differ from the BIOS Setup of previously tested ASUS mainboards in terms of available parameters. For example, we no longer have Command Rate, but there appeared Ai Clock Twister, which you won’t find by P5K mainboards on Intel P35 chipset. Moreover, during our overclocking tests we noticed that by default ASUS P5Q Pro sets suspiciously high Performance Level, which should also affect the performance numbers.

So, we are going to compare the performance of ASUS P5Q Pro against that of ASUS P5K-E. For our tests we will use Intel Core 2 Duo E8600 processor overclocked to 4.41GHz with a lower 9x multiplier (this way we can emulate overclocking of the youngest CPU from E8000 series on new E0 processor stepping - Core 2 Duo E8400).

The bus frequency in this case was set at 490MHz and the memory worked synchronously as DDR2-980 with 4-4-4-12 timings. These settings were used for both platforms.

Now a few words about the differences in settings. Our today’s main hero, ASUS P5Q Pro, configured as seen on the screenshot above, set Performance Level at 12, which is in fact too high for setting performance records. That is why we manually lowered this latency with the help of Ai Transaction Buster parameter. The minimal Performance Level for ASUS P5Q Pro to boot successfully turned out to be 9. This is the setting we ran all our tests with. Another parameter affecting performance is Ai Clock Twister. It had to be set at Light, otherwise the board would be very unstable.

Unlike ASUS P5Q Pro, P5K-E allows changing DRAM Command Rate in the BIOS Setup. However, we couldn’t use 1T setting, because the system would be very unstable failing during OS booting already. However, we managed to set the Performance Level at a much lower rate than on P5Q Pro. As a result, P5K-E worked stably with Performance Level set at 7.

The results in the table below were obtained with these exact settings:

A quick look at the results table is enough to realize that the new ASUS P5Q Pro mainboard unfortunately loses to the Intel P35 Express based solution in all benchmarks. The reason of this fiasco is evident: ASUS P5Q Pro doesn’t allow suing the same aggressive Performance Level settings as the good old boards on the time-tested P35. I believe we have to ask engineers why this is so. So, even though ASUS P5Q Pro can overclock dual-core processors very well, the performance level in this case will be a little off.


Unfortunately, it is not the first time when we cannot draw a completely positive conclusion about an ASUS mainboard. Even though ASUS remains an indisputable leader in the mainboard segment, their products still suffer from a few frustrating drawbacks that may be regarded as critical.

ASUS P5Q Pro mainboard we have discussed today makes a great first impression. It offers a very attractive combination of price and functionality, boasts very convenient and smart design and supports a few very useful innovative technologies, such as ExpressGate – support of a “lite” version of an alternative operating system.

From a practical standpoint, ASUS P5Q Pro leaves ambiguous thoughts. On the one hand, this board seems to have tremendous potential. On the other, it turns out very hard to reveal. The chipset cooling system is not efficient enough in “heavy” modes, and the performance level is far from what other platforms have to offer.

However, we haven’t yet seen any remarkable solutions among competitors’ products on the same Intel P45 Express chipset. This suggests that even though Intel P45Express is the newest platform today, it is not the best one. So, stay tuned for more reviews of P45 Express based products on our site: we haven’t yet given up the search for ideal solution.

However, everything we have just said is true only if you consider yourself an overclocker or dedicated enthusiast. If you do not care about overclocking, but just need a stable contemporary platform, ASUS P5Q Pro is a very good choice that we would gladly recommend.