Asus’ CT-479 Pentium M socket adapter

Manufacturer Asus
Model CT-479
Price (street)
Availability Now
BY NOW, YOU’VE PROBABLY NOTICED that Intel’s Pentium M is gaining attention as a desktop processor, both in desktop motherboards and even in small form factor systems. One problem, however, has been the accompanying laptop chipset, which means greater expense as well as lesser performance relative to other desktop solutions.

Asus has decided to do something about that requirement in rather inventive fashion. The CT-479 is an adapter card that plugs into the processor socket of certain Asus Socket 478 motherboards and converts them to a Socket 479 configuration capable of accepting a Pentium M. This adapter neatly solves both the price and performance issues, the latter by supplying a dual-channel memory configuration unavailable in the Intel 855GME laptop chipset.

How well does the CT-479 adapt the Pentium M for desktop use? We’re about to find out.

A look at the CT-479
Asus sells the CT-479 separately, allowing you to choose the motherboard for yourself. A list of the motherboards currently supported can be found here. Since support for the CT-479 requires a BIOS upgrade, it’s unlikely that you’ll be seeing CT-479 support on any non-Asus motherboards in the future.

The BIOS upgrade could prove to be an interesting problem. If your board doesn’t have a recent BIOS version, you will likely need a Socket 478 CPU long enough to update the BIOS.

Here is a view of the bottom of the CT-479 board. There’s not much to see here except 478 pins. (Uhh, yeah, I counted them…) The board itself is pretty small, since it has to fit inside the Socket 478 heatsink retention bracket and can’t protrude past the arm on the motherboard socket.

The view from the top is a little more interesting. In addition to the laptop socket, there is a floppy-style power connector for the circuitry on the board, as well as jumpers to choose between a 400MHz and 533MHz front-side bus. The kit includes a Molex to floppy adapter cable as well.

The CT-479 also comes with its own heatsink. It’s considerably lighter and smaller than most Northwood coolers, let alone the gargantuan Prescott models. The cut-out allows space for the jumpers and power connector on the CT-479.

Installing the CT-479 is a piece of cake. Lift up the arm on the motherboard’s socket, and the CT-479 just drops right in:

I left the arm up to give you a better idea how the board fits into the confines of the socket area. Once you’ve lowered the arm, you’ll need to install a Pentium M or Celeron M processor into the CT-479 socket, and then install the heatsink.

Here’s the finished install. The heatsink clamps hook into the same holes used by a Socket 478 heatsink.

The majority of the overclocking fun takes place on the page shown below. You can set front-side bus speed, CPU multiplier (this is supported on the Pentium M but not the Celeron M, and the multiplier can only be adjusted down from its original setting) and lock the PCI and AGP busses. Voltage adjustments are available for CPU, DDR and AGP.

It should be noted that BIOS features are implemented not on the CT-479 but on its host motherboard. In addition, supported features vary from motherboard model to motherboard model, so you’ll want to research as best you can to ensure that any advanced features you want (such as CPU voltage control) are available in the latest BIOS of the motherboard you plan to use.

For example, Asus sent along a P4C800-E Deluxe motherboard to go with our CT-479 review unit. This is an Intel 875P-based board that certainly doesn’t skimp on the features. You can read more about it here. The first P4C800-E BIOS with CT-479 support was missing out on the ability to adjust the voltage of the CPU. The most recent BIOS (1022) took care of that problem, and took care of it well.

Unlike previous Pentium M desktop solutions we’ve seen, which capped the CPU voltage at the processor’s upper range, the P4C800-E BIOS allows the voltage to go up to 1.6V. Considering that the maximum recommended voltage for our test chip (a 2.0GHz Dothan) is 1.34V, Asus has given you plenty of rope with which to hang yourself.

Test notes
A few brief notes, because things got a little complicated this time around:

Obviously we wanted to see what effect dual-channel memory would have on the Pentium M’s performance, so testing against DFI’s 855GME-MGF was a must. Since this review also marks a brief return to a socket and chipset of yesteryear, we decided to throw in the hottest chips (both figuratively and literally) ever to run in Socket 478, a trio of 3.4’s: the Pentium 4 “Northwood” 3.4GHz, Pentium 4 “Prescott” 3.4E, and the Pentium 4 Extreme Edition 3.4GHz.

We considered testing the Pentium M configurations on a 400MHz front-side bus, but due to limitations of the P4C800-E Deluxe motherboard, the Asus configuration would have been limited to DDR266 speeds. We wanted a single vs. dual-channel test with the same RAM speed on both the DFI and Asus boards. Since a 533MHz front-side bus is the future of the Pentium M, and 533MHz parts are already available, we therefore used the overclocking features of each motherboard to test our Dothan chip at speeds approximately equivalent to a Pentium M 770, which runs at 2.16GHz on a 533MHz front-side bus.

Why “approximately?” Well, the BIOS on the Asus board has some counting difficulties. Specifically, when you tell it to run at 133MHz front-side bus, it actually runs at 135. We tried turning it down to 132MHz, but the DDR333 memory speed isn’t available below 133MHz. We also tried turning it up to 134MHz, but that threw the RAM divider off. Therefore, we ran both the Asus and DFI boards with a 135MHz front-side bus and a 180MHz memory speed, which matched them up in terms of both front-side bus and memory clocks.

The Asus board’s higher CPU voltage options allowed me to push the Pentium M farther than on the DFI board, and I wound up with a maximum stable speed of 2.57GHz. The chip basically hit a wall here. 2.57GHz required only a slight voltage boost, but even a 10% overvolt wouldn’t keep the Dothan stable at 2.7GHz. I wasn’t willing to go any higher.

Our testing methods
As ever, we did our best to deliver clean benchmark numbers. Tests were run at least twice, and the results were averaged.

Our test systems were configured like so:

Processor Pentium M 755 2.0GHz@2.16GHz
Pentium M 755 2.0GHz@2.43GHz
Pentium M 755 2.0GHz@2.16GHz
Pentium M 755 2.0GHz@2.57GHz
Pentium 4 3.4GHz
Pentium 4 3.4GHz E
Pentium 4 Extreme Edition 3.4GHz

Front-side bus 540MHz (135MHz quad-pumped) 540MHz (135MHz quad-pumped)
Motherboard DFI 855GME-MGF Asus P4C800-E with CT-479 adapter
BIOS revision 55GMDC06 1022
North bridge 855GME 875P
South bridge ICH4M ICH5R
Chipset drivers INF Update INF Update
Memory size 1024MB (2 DIMMs) 1024MB (2 DIMMs)
Memory type Corsair XMS3200 DDR SDRAM at 360MHz Corsair XMS3200 DDR SDRAM at 360MHz
Corsair XMS3200 DDR SDRAM at 400MHz
CAS latency 2 2
Cycle time 5 5
RAS to CAS delay 2 2
RAS precharge 2 2
Hard drive Maxtor DiamondMax 10 250GB SATA 150
Audio Integrated
Graphics 1 GeForce 6800GT with 71.84 drivers
OS Microsoft Windows XP Professional
OS updates Service Pack 2, DirectX 9.0b

Thanks to Corsair for providing us with memory for our testing. If you’re looking to tweak out your system to the max and maybe overclock it a little, Corsair’s RAM is definitely worth considering.

The test systems’ Windows desktops were set at 1024×768 in 32-bit color at an 85Hz screen refresh rate. Vertical refresh sync (vsync) was disabled for all tests.

We used the following versions of our test applications:

The tests and methods we employ are generally publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.

Benchmark results
Memory performance

The Pentium 4’s Netburst architecture and its pre-fetching capabilities win this benchmark, but remember that Sandra is a relatively synthetic measure of memory bandwidth. Remember also that the Pentium 4 configurations used DDR400 while the Pentium M was stuck at DDR333. Speaking of the Pentium M, the dual channels of DDR333 on the Asus board allowed it to post significant gains over the single-channel DFI board.

Cachemem typically presents a more realistic portrayal of memory bandwidth. Here, the Prescott’s improved pre-fetch takes top honors, but note that the Asus Pentium M configurations maintain their healthy lead over the DFI configs.

While the Asus board beats the DFI hands down in terms of bandwidth, latency is another story, as the Asus Pentium M configurations come in dead last by a significant margin.


Unreal Tournament 2004

It’s benchmarks like this that started people clamoring for a Pentium M desktop solution in the first place, as the slowest Pentium M still comes in ahead of even the Pentium 4 Extreme Edition. The added memory bandwidth of the CT-479 system benefits UT slightly at 2.16GHz. Doom 3

The Pentium M configurations extend their lead over the Pentium 4 in the Doom 3 benchmark, and once again the Pentium M 2.57GHz configuration takes the lead by a relatively large margin. Far Cry

The Extreme Edition’s 2MB of L3 cache helps it to take down at least one of the Pentium M configurations here. Memory bandwidth seems to matter quite a bit in Far Cry, as the dual-channel CT-479 system at 2.16GHz manages to outdo even the overclocked DFI configuration.

Sphinx speech recognition
Ricky Houghton first brought us the Sphinx benchmark through his association with speech recognition efforts at Carnegie Mellon University. Sphinx is a high-quality speech recognition routine that needs the latest computer hardware to run at speeds close to real-time processing. We use two different versions, built with two different compilers, in an attempt to ensure we’re getting the best possible performance.

Memory bandwidth is exceedingly important to Sphinx, and it shows here. The DFI configurations and their single channel of memory simply can’t keep up with the Asus board’s dual-channel configurations. Among those dual-channel configurations, the Pentium M at 2.57GHz is fastest. LAME MP3 encoding
We used LAME to encode a 101MB 16-bit, 44KHz audio file into a very high-quality MP3. The exact command-line options we used were:

lame –alt-preset extreme file.wav file.mp3

CPU performance is everything to LAME. Note that the two Pentium M 2.16GHz configurations tied exactly, while the performance of the overclocked configs tracks very well with increasing clock speed. DivX video encoding

One area where the Pentium 4’s Netburst architecture has always excelled is media encoding, an an excellent example of this is the XMPEG benchmark. Dual memory channels help the Pentium M only slightly here. Cinebench 2003

Hyper-Threading can be a real asset if an application can take advantage of it, as we see here. The Prescott lags considerably behind the two Northwood configurations, but with multithreading it still manages to beat the fastest Pentium M. When restricted to a single thread, however, the fastest Pentium M configuration manages to come out on top. Yonah, anyone?

Power consumption
We measured the power consumption of our entire test systems, except for the monitor, at the wall outlet using a watt meter. The idle results were measured at the Windows desktop, while load results were obtained after firing up one instance of Prime95 for the Pentium M and two instances for the Pentium 4 processors with Hyper-Threading.

Here we see another reason why people are clamoring for Pentium M on the desktop. The Pentium M’s power consumption is dramatically lower overall. Also, while the Pentium 4 chips tack on as much as 114W going from idle to full load, the Pentium M adds only 23W at most. Clearly, DFI’s use of a laptop chipset pays some dividends here, as well. If you’re wondering how the DFI board can overclock a processor by 300MHz without consuming any more power either at idle or under load, well…. so am I. I reran the tests to be sure, but they always turned out the same. My current theory on the subject revolves around little green men, but it’s still a work in progress.

Compared to other available Pentium M desktop solutions, the CT-479 is compelling. Currently, the CT-479 is available for approximately $42, and compatible motherboards are available for as little as $80-85. For that price, you get dual channels of DDR333 memory and the ability to raise the CPU voltage until the blue smoke escapes. Neither of these options is available with dedicated Pentium M motherboards, and the CT-479 is cheaper than those motherboards. The combination of price and features makes the CT-479 difficult to beat. If anything, the CT-479 solution suffers from the age of its host motherboards, since the use of the Intel 865PE and 875P chipsets means that you’re stuck back in AGP and PCI land.

For nearly all consumers interested in the Pentium M, the CT-479 offers both better performance and a lower cost than other solutions, and that’s really all that needs to be said. If you’re interested in a quiet, Watt-sipping Pentium M desktop, the CT-479 is as good as I’ve seen.

Comments closed
    • Hector
    • 14 years ago

    LOL guys I”m talking about the P6 core from its first incarnation as the Pentium Pro to its latest incarnation as the Pentium M not that they going to call it P6. They prolly call it P5.

      • Dr. Evil
      • 14 years ago

      Uhh, we already did this board+adapter versus a native Pentium M board. In this review.

      As for the Slashdot poster, his point would be more interesting if he weren’t full of it. Let’s break it down point by point:

      1) “…using the northbridge for a P4 with a Pentium M will certainly not give very good results.”

      The power consumption numbers from the article indicate a relatively small 18W increase going from a laptop chipset to the 875P chipset. Moving from a 3.4 Northwood (the best of the P4’s in the test in terms of power consumption) to the Pentium M results in a reduction in power consumption of a hundred watts. But I guess that’s not a “very good result.”

      2) “…the Northbridge… will over-take the CPU… as the hottest component in a computer.”

      This is laughable. Tell you what, we’ll set up a couple of motherboards with 3.8 Prescotts. I’ll take the heatsink off the Northbridge and place my thumb on it, and you do the same with the CPU. Care to take any guesses as to whose flesh is going to start smoking first?

      3) “If you take a year-old system, and put all the components … in a brand-new motherboard, you’ll see the power consumption go up 10-20 watts.”

      Proof, please? And let’s just assume for a moment that this is the case– is 10-20W that big a deal when going from idle to load on a high-end Intel system causes a 112W increase in power consumption?

        • eitje
        • 14 years ago

        i felt the same way. someone further down in the slashdot page says the same thing. it’s amazing how brashly people will say “someone needs to test this because, based on numbers i’m making up, i’m right.”

        • Swampangel
        • 14 years ago


    • Dposcorp
    • 14 years ago

    <wished he was clever enough to have gotten in on this earlier>

    • tay
    • 14 years ago

    The reason it uses the same wall power at 2.16 and 2.43 Ghz is that the difference is 270 Mhz or 13%. 13% of 23 W (peak) is 2.5W. Your measuring equipment is probably only sensitive to +/- 5W.

    • AmishRakeFight
    • 14 years ago

    I just had a flashback to the old slot to socket pentium III adapters. Scary stuff.

      • bhtooefr
      • 14 years ago

      Hmm… the history of socket adaptors…

      Some crazy nut at a mobo maker (Tyan or Asus, IIRC) realizes that Pentium II mobos are better than Pentium Pro mobos, yet Pentium Pros are better for server apps than Pentium IIs, and they’re a LOT cheaper than Pentium II Xeons. Oh, and they’re chipset compatible. Bring in the first slotkets – Socket 8 to Slot 1.

      Some other crazy nut at another mobo maker (I believe ABit) realizes that people may want the (overclocking) features of a Slot 1 mobo, but the cheap Socket 370 Celerons. Bring on the first Slotkets(tm) – Socket 370 to Slot 1. This goes on for a while, with various versions by many manufacturers…

      Somebody at PowerLeap realizes that there are some perfectly good Socket 370 mobos made for Mendocino Celerons (PPGA), but someone wants to use a Coppermine (FCPGA) or Tualatin (FCPGA2) chip on it.

      Somebody at PowerLeap realizes that there are some perfectly good Socket 423 mobos lying around, and some good Northwoods. Bring it on!

      Yet another PowerLeap thingy… someone finds out how to add hyperthreading support to mobos that don’t support it normally.

      Someone at PowerLeap figures out how to make a Golden Fingers card for *[

        • AmishRakeFight
        • 14 years ago

        Bravo! Just looking at that thing gives me the jibblies.

    • DrDillyBar
    • 14 years ago

    w00t! Thanks ASUS.
    Good article.
    Someday, I’ll use this to upgrade my P4C 3.0GHz.
    folding folding all da time.

      • bhtooefr
      • 14 years ago

      Be careful, there.

      On most WUs, the P-M is a dog.

      On the p1147s, from what I’ve heard, it’s great, though.

      I think Tarx is our resident P-M folding expert, FWIW.

    • Naito
    • 14 years ago

    Why in the world did you only compare against P4? The P4 sucks in just about everything except video encoding. Where’s the comparison against the Athlon64? That’s where the real competition is.

      • bhtooefr
      • 14 years ago

      Hmm… First, they may have been time-limited.

      Second, they wanted to test on the same mobo. You can’t run an A64 on a Pentium 4 mobo, unless it’s an ECS PF88!

    • blastdoor
    • 14 years ago

    I wonder which is bigger: the harm Intel does AMD through its co-marketing or the benefit Intel gives AMD by stubbornly refusing to dump Netburst and switch their desktop and server lines to Pentium-M based solutions. I suspect it’s the latter that’s larger.

      • droopy1592
      • 14 years ago

      megaclockahurtz marketing.

    • Hector
    • 14 years ago

    Half the power, twice the performance what’s not to like over that marketing gimmick called prescott?

    And Merom/Conroe is supposed to be a improved architectrue similar to P-M, but with a lot of enhancements, dual core, 4mb l2 cache, not much bigger than a northwood die on 65nm. Really looks like cedarmill/presler is the end of netburst for desktops, finally! And AMD is in real trouble come late 2006 early 2007 …you’ll be seeing bargian basement $40 chips from them again just to keep people employed LOL All fear p6:D

    • Samlind
    • 14 years ago

    Well, Newegg says that’s a $650 processor. I’d say for my $650, I can get something that clobbers it in a SFF, does 64 bits and PCI-e to boot.

    Pentium M is an interesting package, but I haven’t seen any compelling application/value/performance from it yet.

    • Proesterchen
    • 14 years ago

    Nice article, though I wonder if you could stably o/c the Pentium M FSB to FSB800 (w/ DDR400) given its multiplier control and what kind of performance that would gain, if any.

    • Prototyped
    • 14 years ago

    Where are the i915GM motherboards?

    Sonoma on the desktop, now!

      • bhtooefr
      • 14 years ago

      The AOpen i915GMm-LFS is what you want.

      However, I’d like to see a Socket 478 or 479 desktop board using a DESKTOP i915G…

    • UberGerbil
    • 14 years ago

    Too bad ASUS doesn’t make (real) SFFs and/or Shuttle doesn’t have an adaptor like this. And yeah, I know ASUS has some oddball small/media PCs. I’ve never seen one in the flesh.

      • continuum
      • 14 years ago

      Adapting this into a Shuttle would be a pain in the butt due to space constraints. However, a native Shuttle Pentium-M box… mmmm…

        • bhtooefr
        • 14 years ago

        And Shuttle’s got TWO in the pipeline – one a slimline media center, and one a traditional cube.

        It wouldn’t be too hard to get one of those in, though. The ICE wouldn’t be usable, but the ICE isn’t exactly necessary when the CPU is that low power…

    • Mr Bill
    • 14 years ago

    I want a socket adapter to put an A64 X2 or an opteron into my MPX duallie slots.

      • UberGerbil
      • 14 years ago

      Just buy a new motherboard, and get all sorts of goodness — PCI-E, integrated NICs, SATA, faster memory — for free.

        • Mr Bill
        • 14 years ago

        K7D Master-L has integrated NIC. Already have PCI-X 66/133 U320 SCSI raid don’t want/not PCI-E nor SATA. Don’t want to buy more expensive, only slightly faster, DDR.

        • hmmm
        • 14 years ago

        PCI-E isn’t free when you have to buy a new card. 🙁

      • Vertigo
      • 14 years ago

      Hate to disappoint you, but unlike P-III -> P-M, Athlon MP to Opteron actually involved some serious architectural changes like moving the memory controller from the northbridge onto the CPU die. That’s why Athlon64/Opteron sockets have [2,3]00 more pins than Athlon XP/MP. It’s never going to happen.

        • Mr Bill
        • 14 years ago

        I know this, and yet if an electrical engineer wanted to, I think it could be done. Of course I agree, no EE would think it worth doing.

    • Spotpuff
    • 14 years ago

    So where were the A64’s in the power consumption comparison? I know the article was supposed to compare mainly P4 vs PM, but Athlons have fairly low power consumption compared to P4s as well, don’t they?

    • spuppy
    • 14 years ago

    Yoooooooooooooooonahhhhhhhhhh! Where aaaaaaaaaaaaaaaaaaaaaare yoouuuuuuuuuuuu

      • UberGerbil
      • 14 years ago

      Waiting for the 65nm process node to get worked out, apparently.

    • dragmor
    • 14 years ago

    I’m more interested in the reported temps, and the ability to put a bigger heatsink on it for a little/no noise solution.

      • bhtooefr
      • 14 years ago

      IIRC, you’d have to mod an ordinary heatsink so it has the hole to plug in the power connector.

    • Dposcorp
    • 14 years ago

    where is my 64 bit goodness?
    Nice review, but i’ll pass.

      • bhtooefr
      • 14 years ago


      Just wait for Yonah.

        • UberGerbil
        • 14 years ago

        Which apparently won’t have it either, at least in the initial steppings.

        Sossaman might. Memrom almost certainly will. Even some later stepping of Yonah might. But there’s no sign of it in the initial engineering samples or Intel presentations on Yonah.

          • bhtooefr
          • 14 years ago

          True, but as I understand, it’ll have the transistors there, just one bridge will be set so that it’ll be 32-bit only.

          That means that this “newer stepping” is VERY likely to occur, much like the 5×1 P4s.

            • UberGerbil
            • 14 years ago

            I guess we’ll have to wait and see. Those rumored transistors were also supposed to be on some early P4s and they never were unlocked. I’m willing to bet that Intel doesn’t bother unless Windows x64 (or 64bit Longhorn) starts to get some serious traction (eg something like HL2.5 or Doom3.5 shows up with important 64bit-only features). More likely, Intel will unlock them on Sossaman (and in fact that might be the only significant difference between Yonah and Sossaman, with everything else being in the chipsets) since 64bit makes a lot of sense on servers and no where near as much in laptops.

            • Proesterchen
            • 14 years ago

            64bit is a Merom affair, Yonah doesn’t have it.

            • bhtooefr
            • 14 years ago

            Crap – l’Inq is saying that Napa64 will be a tweaked Yonah chipset (*cough*i945GM*cough*) strapped to a Merom…

            They’re also talking about a Pentium M with a 60W TDP, and running at 3GHz for a dual core chip. Damn, Intel’s joining the short-pipeline 3GHz race AND the short-pipeline 3GHz dual core race, now. Want to bet that AMD’ll get the FX-59 out before Intel gets the PMEE out? However, I don’t expect an X2 5800+/6000+ before the PMEE…

      • Vrock
      • 14 years ago

      Not like 64 bit “goodness” is worthwhile….still.

    • bhtooefr
    • 14 years ago

    Decent review, and it’s nice to see the P-M whoop up like that…

    However, what about getting an ACTUAL P-M 770?

    I just need a LGA775 Yonah. Now.

    [b]Edit:[/b] Another option that the CT-479 gives you – the starting FSB is by a jumper, is it not? You specifically picked a P-M that would OC to 2.13 at stock multi, right? Then why did you not switch the jumper from 400 to 533?

    • castlevanity
    • 14 years ago

    I want my Pentium M

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