The CT-479 Arrives

Last Thursday Legit Reviews posted an article talking about the ability to run an Intel Pentium M on a Socket 478 motherboard thanks to the ASUS CT-479 upgrade kit. We have spent some time with the kit that we "pre-viewed" in the first article and now have some benchmark numbers to share. For this article we are using the ASUS CT-479 CPU Upgrade Kit on the ASUS P4P800 SE motherboard that uses the Intel 865PE chipset.  If you would like a background on why you would want a Pentium M processor on a desktop board or what this kit exactly does please refer to part one, before going on. 

ASUS CT-479 Pentium M adapter

The ASUS CT-479 only works on a handful of ASUS motherboards for the time being.  Officially it is only supported on the ASUS P4P800 SE and the P4P800-VM motherboards.  We selected the ASUS P4P800 SE motherboard with BIOS version 1008.015 (build date 2-17-2005) to be the test bed for the Pentium M adapter kit.

ASUS CT-479 Pentium M adapter

Included with the CT-479 are the installation guide, a heatsink/fan, one 4-pin power cable, and the socket adapter.  The only "tool" needed for this kit is a flat head screw driver to secure the Pentium M processor in the socket just like what is done on a notebook computer.  Since noise is a big issue I'll take a second and talk about the bundled cooling solution.  It spins at roughly 3,000RPM's with a maximum airflow of 32.5CFM.  As far as noise is concerned you are looking at roughly 30dB-A, which is roughly the same noise level found on a Geforce 6800 series video card. 

Let's move on to installing the CT-479 on the P4P800 SE.

Installing the ASUS CT-479 CPU Upgrade Kit

Installing the ASUS CT-479 is simple and should honestly take under 10 minutes for the average consumer.  As always only install computer hardware if you feel comfortable doing it! 

ASUS CT-479 Pentium M adapter

First make sure you line up the pins on the base to make sure you install it the right way and don't bend any adapter pins.  Once you know the way it needs to be placed in the socket lift the socket lever and insert the adapter. Simply close the lever on the motherboard socket and the adapter is locked into place.

ASUS CT-479 Pentium M adapter

Now that the card is locked into place it should like ours does in the above image. Next we need to set the blue Front Side Bus (FSB) jumpers for the type of Pentium M processor being used. (either 400MHz or 533MHz)  Set the jumper labeled J1 to pins 1-2 & 4-5 for FSB 400 or pins 2-3 & 5-6 for FSB 533.  Once you have this all done you are ready to insert the Pentium M processor of your choice in the new socket.

ASUS CT-479 Pentium M adapter

On our system we used the fastest retail Intel Pentium M processor on the market the Intel 770.  Simply place the processor into the socket and secure it in place by turning the lock with a flat-head screw driver to the locked position. Now simply plug in the supplied power cable onto the adapter card and connect it to a 4-pin molex connector on your power supply.

ASUS CT-479 Pentium M adapter

The last step to the installation is to put on the heat sink/fan.  If you notice the HSF is unique because it has a special notch in it to avoid the jumpers and power header found on the adapter.  The supplied thermal pad works just fine, but if you are going for the lowest possible temps then remove this now and apply your favorite thermal compound.  

ASUS CT-479 Pentium M adapter

With the heat sink set in place go ahead and attach the clamps to the motherboard mounting rails and connect the fan power cable to the header found on the board.  With this last step completed everything impacted by this adapter kit is done. Like I noted at the top of this page this installation is straight forward, simple, and something almost anyone can do.

Let's see if our installation worked by powering up the system...

ASUS CT-479 Pentium M adapter

SUCCESS! Looks like the ASUS P4P800SE correctly identified the Pentium M processor and the system booted up just fine. Let's move along and see what this "special" BIOS has to offer.

Trying to figure out the BIOS

It is clear that ASUS has to customize BIOS's found on current socket 478 boards to support these new socket 479 Pentium M processors. One of the biggest complaints of the overclocking/enthusiast community has been on the lack of voltage options, dividers, and memory timings on previous Intel 855GM boards such as the ones by DFI and AOpen.  With high hopes of ASUS desktop board Frequency/Voltage settings we took dove into the BIOS.  What we found was to be expected for a "first ever" hardware product.   

ASUS CT-479 Pentium M adapter

Going to the screen that every enthusiast and overclocker goes to first we looked at the system frequency/voltage menu and found some positives and negatives at the same time.  The ASUS P4P800SE BIOS allows you to crank the External Frequency all the way up to 400MHz, which is overkill for any current Pentium M on the market no matter what cooling is being used.  The AGP/PCI bus can be locked down to 66/33 for better overclocking attempts. Anyone using the DFI 855GME-MGF knows they lack any vDIMM and vAGP settings, but that is not the case here as the vDIMM goes up to 2.85V and the vAGP tops out at 1.80V.  All in all it's not too bad till you think about what is missing. 

Take another look above and see if you can figure it out... Oh yes, what about the multiplier and vCore settings for the processor.  Sadly even though the Pentium M is an unlocked (by Intel) processor ASUS fails to place multiplier adjustments in the BIOS.  Also there are no settings for the vCore on the processor.  You are basically stuck with whatever setting is pre-programmed for the CPU you are using. In the case of out Intel 770 processor we were stuck running 1.36V.

UPDATE: A few hours after posting our article ASUS-USA delivered a Beta BIOS to us. They have filled every overclockers dreams with Voltages all the way up to 1.95V.  The BIOS also improved graphics performance a ton!  We will be updating the rest of the review today with the benchmark results from the latest BIOS. ASUS really pulled one off for the enthusiast community with this BIOS release. 

ASUS CT-479 Pentium M adapter

Let's take a look at the available memory dividers.

ASUS CT-479 Pentium M adapter

With our Intel 770 set to the default settings (133MHz External Frequency then quad pumped to 533MHz FSB) we found that we only had DDR 266 and DDR 333 options.  Not what any overclocker wants to see by any means as 266MHz is a 1:1 divider and the 333MHz option is only a 2:3 divider.  Unhappy with the memory dividers in the BIOS, I came across something by accident that can be seen below.

ASUS CT-479 Pentium M adapter

I kept all the other options the same and raised the CPU External Frequency up to 200MHz.  I went back down to the DRAM Frequency and noticed many more dividers magically appear.  The only down side is that they only are optional from 200MHz to 400Mhz, which is far beyond any Pentium M processor i have ever seen handle.  How you can overclock this board then one might be thinking.  

ASUS CT-479 Pentium M adapter

Luckily, ASUS left their AI Overclock Tuner functional and it offers overclocking in 5, 10, 20, and 30% increments over default speeds.  When one of these options is selected the BIOS automatically bumps up the voltage.  We were able to run the 20% overclocking option and it automatically bumped up the vCore from 1.36V to 1.44V.

Now that we've looked at the kit, installation, and the BIOS we can move right along to performance numbers.

Pentium M Overclocking/Thermal Testing

Overclocking Options:

Overclocking can be done easily done via the pre-programmed percentages found in the ASUS P4P80SE BIOS.  Enthusiasts can of course manually set their settings, but when doing so they lose the voltage boost provided by the pre-pregrammed settings.  Our best "automatic" overclock using the Intel 770 processor was 20%, which resulted in 2.56GHz or a 430MHz increase in core frequency with the memory running at dual channel DDR400 and the FSB at 640MHz.  Our CPU-Z of this overclock has been verified and can be seen online here.

We tried overclocking the board manually and were able to raise the front side bus 5MHz higher than the 20% overclock we just tried before the system became totally unstable. This time we were able to reach 165MHz FSB for a core frequency of 2.64Ghz.  A 510MHz overclock is a healthy 24% boost in frequency over the rated 2.13GHz it should be running at.  Our CPU-Z of this overclock has been verified and can be seen online here.

Just before publishing this article I spoke with Franck Delattre, the webmaster of, and author of cpuz and clockgen.  After conversing about the board and BIOS limitations Franck asked us to try out a tool called EIST that could be used to adjust the Pentium M's multiplier and core voltage (only down).  We also downloaded the correct ClockGen (CG-ICS952607) for the ASUS P4P800SE motherboard to allow us to adjust the front side bus (FSB) dynamically via the desktop.  All of these programs that Franck created work fine on our test bed and allowed us to do everything we wanted, but up the vCore of the processor.

ASUS CT-479 Pentium M adapter thermal temperatures

As you can see in the above image I was able to adjust the multiplier from 6-16 and could use ClockGen to boost the FSB levels.  We lowered the CPU Clock down to see 6 (the lowest possible setting)  and went to find the highest FSB we could use without voltage mods.  We were able to reach 173MHz FSB for a BUS Speed of 690MHz.  Our CPU-Z shot for this can be seen online.  Using this software we were not able to get much more head room out of our processor, but posibbly with a voltage mod for the vCore we can.  Overclockers have noticed a hurdle at the 170-175MHz range on i855GM boards and again it holds true on the i865PE/CT-479 platform.  Time will tell if ASUS can update the BIOS to improve performance/overclocking and Legit Reviews will continue to look into Pentium M overclocking. 

UPDATE: The new ASUS Beta 1009 BIOS is extremely overclocker friendy.  We were able to reach 220MHz FSB at a multiplier of 6.  We were able to reach 200Mhz (800MHz QDR) all the way up to the 12 multiplier and then hit 198MHz @ 13.  On 3-25-2005 we put water cooling on the test bed.   Check the this thread for up to the hour overclocking updates. On 3-26-2005 we were able to hit 200MHz FSB with a multiplier of 13.  Below is a screen shot.

ASUS CT-479 Pentium M adapter thermal temperatures


Thermal Testing:

One of the main advantages of the Pentium M processor over competing processors are the low thermal properties produced.  In the case of the Pentium M being used in conjunction with the ASUS CT-479 adapter we believe that the Winbond W83627 Super I/O found on the ASUS P4P800SE can correctly read the voltages on the Pentium M processor.  If you recall the CPU or "Core" temperatures seen via monitoring software programs are not a measure of actual temperatures. The temperature is actually ?calculated? by the Super I/O chip that is associated with the thermal diode. There is a parameter for the calculation that is used and it comes from the I/O chip vender. Since the W83627 chip is also used on the DFI 855GME-MGF Pentium M board hopefully all of them detect the right voltages.  

ASUS CT-479 Pentium M adapter thermal temperatures

At idle our Intel Pentium M 770 processor is just a single degree Celcius above the motherboard temperature and that is using the thermal pad that comes with the kit!  When running at full load, temperatures were observed at 40C, just a 4C rise from the idle temperature.  This is not too bad when you think of the original Intel Prescott 3.2GHz we tested last year that ran at 51C with the factory HSF and 42C with water cooling from Corsair Memory.

UPDATE:  Using Corsair's HydroCool 200ex we were able to run the Intel 770 at default clocks and voltages at 27C and a MB temp of 33C.  We used the standard Corsair HydroCool Block and a chipset cooler for the north bridge.  Pictures of this can be seen in this forum thread.

Memory Bandwidth/Super Pi Testing

Memory Bandwidth Testing:

Everest 2.0 is a professional system information, diagnostics and benchmarking program for Win32 platforms. It extracts details of all components of the PC. It also tests the actual read and write speeds of your memory to give a fairly accurate look of true memory performance.

Pentium M Read Bandwidth

Results: It is fairly obvious that moving to dual channel memory does impact the Dothan for the better.  On the i855GM chipset the Intel 770 was getting 3.2Gb/Sec and on the i865PE chipset it was observed getting 3.9Gb/Sec.  An extra 700MB/Sec of bandwidth transfer should boost the performance levels of the Dothan processor.

Let's take a look at the write bandwidth benchmark results now.

Pentium M write Bandwidth

Results: Again as expected the ASUS i865PE motherboard with the CT-479 adapter performed better than the DFI i855GM motherboard.  There was only a 378MB per second bandwidth difference shown by the data, but that is still a 58% increase in the write bandwidth thanks to moving over to dual channel.

SuperPi 1.1e :

SuperPi calculates the number Pi in this raw number crunching benchmark. The benchmark is fairly diverse and allows the user to change the number of digits of Pi that can be calculated. In this benchmark we ran SuperPi to 1 million places.

Pentium M Read Bandwidth

Results: Super Pi is a common benchmark used in the enthusiast community to judge system performance levels.  The Intel 770 processor with the ASUS CT-479 adapter on the i865 board scored two seconds faster than the Intel 770 on the i855GM powered motherboard. When overclocked to 2.64GHz scores were able to reach 28 seconds.

Professional Testing


CINEBENCH 2003 is the free benchmarking tool for Windows and Mac OS based on the powerful 3D software CINEMA 4D R8. The tool is set to deliver accurate benchmarks by testing not only a computer's raw processing speed but also all other areas that affect system performance such as OpenGL, multithreading, multiprocessors and Intel's new HT Technology. Again, higher Frames/Second and lower rendering time in seconds equal better performance.

Pentium M

Results: Here the Intel 770 processor scores the same on both platforms. When overclocked the Dothan actually beats out the A64 4000+ and the Intel 660 processors.

ScienceMark 2.0 Beta:

Science Mark 2.0 is an attempt to put the truth behind benchmarking. In an attempt to model real world demands and performance, ScienceMark 2.0 is a suite of high-performance benchmarks that realistically stress system performance without architectural bias. For the Memory Testing, higher numbers represent better performance. On the remaining tests, lower seconds represent better performance.

Pentium M

Pentium M

Results: Here we once again see the "adapted" Pentium M test system out perform the 855GM board. The Pentium M also tries to hang tough with the other desktop processors.

POV-Ray/Comanche 4 Testing

POV-Ray 3.6.0:

The POVRay benchmark is great for showing the performance levels of various processors and compilers by timing how long it takes for POV-Ray to render a standard image with standard parameters.

Pentium M

Results:  Here we see a big difference between the i855GM and i865PE test platforms.  The ASUS CT-479 system was able to finish the rendering nine seconds faster then on the DFI 855GME-MGF board.

NovaLogic; Comanche 4 & DOOM 3

The Comanche 4 benchmark demo is a unique benchmark as it represents a real-world gaming experience. It contains the single player Eagle's Talon mission from the game as well as a detailed cinematic. This DirectX 8.1 benchmark demo measures your system's performance in the standard frames per second format.

Pentium M

Results:  The ASUS P4P800SE with Beta BIOS 1009 takes the lead over the i855GM board.  There is little doubt that the extra memory bandwidth that the i865PE chipset really does help gaming performance

Final Thoughts/Discussion

The Two Desktop Options i865PE or the i855GM

Nathan Kirsch's Thoughts:

From the second the product arrived for testing it was clear that ASUS has put much time and thought into the development of the ASUS CPU Upgrade Kit.  Their goal was to bring quiet and cool processors to the desktop without compromising system performance.  I must agree with that goal and feel that ASUS was able to reach it in a cost-effective manner.  The DFI 855GME-MGF motherboard retails for $210, where on the other hand the ASUS P4P800SE is only $98, plus the CT-479 adapter that will run under $50.  For consumers always worried about the next product coming out, we have some information for you there too.  Micro-ATX "Alviso" boards based on the 915GM chipset are due out in a matter of weeks.  Information and images on one of these boards, the AOpen i915GMm-HFS,  can be found on this thread in the Legit Forums. AOpen confirmed pricing would be set at an MSRP of $300 for their i915GMm-HFS board.  Thus, making it nearly double the cost of the CT-479 adapter kit/i865PE motherboard combination. 

The idea to put Intel Pentium M ? the chip originally designed for mobile computers ? into desktops has been around for a quite while, and Legit Reviews sees the trend staying around in the future.  With Intel seeing companies selling Pentium-M adapters and desktop boards it may be only time till Intel jumps on board and designs a mobile desktop solution.  If corporate buyers pick up on the incredibly quite office space that the Pentium M's bring it may only be a matter of time before the blue giant steps into the market. 

In terms of performance the Pentitum M processor runs very well when compared to the Pentium 4 6XX series and AMD Athlon64 processors.  This is impressive when you take into consideration the Pentium M lacks Hyper-Threading, EMT64 support, and runs at a lower frequency than most processors on the market.  The fastest Pentium M on the market today is the Intel 770 that runs at 2.13GHz.

With all that said the ASUS CT-479 brings a small performance increase, silent computing, and better overclocking results over the i855GM chipset boards that we have seen from AOpen and DFI. Overclockers looking for the unlocked holy grail of voltages have just found their solution and they don't even have to mod it!

Legit Bottom Line:

The ASUS CT-479 is one of the most cost-effective ways to bring the power and the silence of a Pentium M processor to your desktop.

The ASUS P4P800SE & ASUS CT-479

The CT-479 Socket Area