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The Xeon Thread v2.0 Complete

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Dec 7, 2002
With the advent of dualcores and development of workstation-class motherboards for them, there's little reason (as of now) for the enthusiast to consider the Xeon platform any longer. So, I am retiring this thread. The info's still good, but its future's going nowhere.

Note: this thread deals with P4-generation Xeons only


What are Xeons?

Xeons are Intel's CPUs for multiprocessor systems. It used to be that regular Pentium CPUs could be run in SMP, but the only way have dual P4s is to have dual Xeons. The only differences between Xeons and P4s of the same core are a different socket and the SMP capability. Occasionally, Xeons will bring new core enhancements to the market before regular P4s, such as HT, EM64T, etc.

Why go with Xeons?

  • Price- A typical Xeon platform is cheaper than an Opteron setup, and highly overclockable Xeon CPUs can be found slightly cheaper than their Opteron counterparts. Also, Canterwood-based Xeon motherboards, the most popular right now, let you use your existing AGP cards and DDR, so you can still get excellent performance without the DDR2-PCIe upgrade expense. Athlon MPs are cheaper, especially good for folding :), but lag a generation behind.
  • Performance- For particular applications, especially for media encoding, photo editing, and rendering, a pair of Xeons offer the best performance available. Excellent real-world benchmarks can be found at GamePC. Of course, Opterons own the server and gaming segments, along with a few media apps. Xeons still hold their own in gaming, at least.
  • Stability- Pretty much an older issue, maybe not an issue, but it might be an advantage to some people. Intel chipsets are known for stability, whereas AMD's are not. Older Athlon MP chipsets and perhaps early Opteron chipsets had varous hardware compatibility and other issues. Now, with the NForce professional and errata in the first shipments of the e7525, this may be changing.
  • Motherboards- One of the biggest advantages Xeons have over Opterons and especially Athlon MPs. There are multiple generations of ATX-sized, AGP/PCIe, overclockable Xeon motherboards both with and without PCI-X, which means that you can get the right amount of capabilities you need at a good price (compared to other SMP motherboards) and without the hassle of the EATX form factor. There's also an ATX-sized SLI board (IWill DN800-SLI), for which there's no Opteron equivalent.

Why bother now with dualcores?

  • Price- Kind of the same thing mentioned above, you can get SMP power without having to switch other system components. You can also buy one CPU now, and wait and save up for the next one.
  • Performance- You don't get HT with anything but the Extreme Edition, whereas you can buy a pair of low-end Xeons with HT for around half the price. Also, dualcores only have 1 MB cache per core, whereas newer Xeons have double the amount, 2 MB per core. Depending on your application, this can make a big difference.
  • Motherboards- Xeon motherboards generally offer more capability for I/O, with PCI-X and more PCIe, which lets you use higher-end storage adapters to take advantage of larger RAID configurations. There are a couple Supermicro LGA775 boards with PCI-X floating around, though.
  • Overclockability- Xeons tend to overclock slightly higher than the P4s of the same core- since they're Intel's high-end chip, they're probably binned a bit. Also, two physical CPUs means that the heat output is not put on one heatsink, but two. With less stress on the CPU cooler, it may be easier to achieve lower temps and therefore overclock higher. While the highest achieved FSBs on Xeon motherboards are typically lower than those on regular P4s, the default multipliers are higher, so it evens out.
  • Future CPUs- Rumors have Paxville coming out in a DP version for socket 604, which is supposed to be a dualcore chip with 2 MB L2 per core. Also, there’s Sossaman, a Pentium M derivative to become a sort of LV Xeon in the near future.
  • Coolness Factor- Admit it, the allure of high-performing, exotic, or otherwise special hardware is part of being an overclocker. It's fun to play around with stuff not normally associated with the desktop :)

What are the differences between P4 Xeons?

There are two main iterations of the P4 Xeon, the DP and MP. DPs are "normal" 2-way Xeons, which are what are generally available. MPs are for 4- and 8-way systems, and cost thousands of dollars- they're completely out of place for us.

The cores are:
  • Foster- found with 256k L2, HT on a 400 MHz bus. Akin to a Willamette- watch out and don't get these.
    Fosters are not compatible with most any motherboard newer than the e7505 chipset.
  • Prestonia- found with 512k L2, HT on a 400 or 533 MHz bus. Akin to a Northwood- these are the most popular and first to be overclocked.
  • Gallatin- an MP chip that slipped to DP. 533 MHz Prestonia with 1 or 2 MB L3 cache. Akin to a P4EE.
  • Nocona- found with 1 MB L2, doubled L1, improved HT, EM64T, on a 800 MHz bus. Akin to a Prescott.
  • Irwindale- Nocona with 2 MB L2. Akin to a Prescott-2M.

The sockets are:
  • Socket 603- Fosters and 400 MHz Prestonias. Older socket, these CPUs, except for Fosters, are compatible in newer motherboards.
  • Socket 604- Where the action is. 533 MHz Prestonias and 800 MHz Noconas/Irwindales. Just Socket 603 with an extra non-functioning pin to make it special.

All Xeons have a downwardly unlocked multiplier- you can lower it freely below stock, but can't raise it above. However, rumor/speculation over at 2CPU indicated that there might be a split second on boot where the high, stock multiplier is in effect until the lower one comes in- you might have to have enough voltage to get over this short hump so that you could get at the stable lower multi when overclocking.

How does the cache affect things?

Cache is very important to the Pentium 4 "Netburst" architecture, and with the extra options in some Xeons, should be considered a bit more. Performance boosts depend on the application. Photoshop seems to get the largest boost, followed by some renderers, like 3DSMax, and games.

L1 cache is very small and contains mostly instructions and important immediate things, it's quite standard and not usually looked at. The Prescott/Nocona has a doubled L1 cache, which does bring a notable performance increase and helps compensate for the longer pipeline.

L2 cache is the standard cache that we look to for performance. It serves as a local bunch of RAM so that the CPU can access program information and other things far quicker for processing.

L3 cache is an extra, periphery level of L2. However, in the P4 architecture the contents of each cache are mirrored in each other, so the L3 is effectively cut by 512kb. More L2 is better than an extra chunk of L3, but remember that the Nocona/Irwindale has other architectural changes; it doesn't get performance differences just from its cache.

Hyperthreading vs two physical CPUs

Hyperthreading is nowhere near equal to having two CPUs. HT boosts specific applications that are written for it by jamming in more threads at the same time. Depending on the application, this may significantly increase performance. Two real CPUs not only boost SMP-optimized applications by an even more significant amount, but they also handle twice the load at the same time. This is what gives the “silky-smooth” feeling to SMP, and why it is so attractive- you can burn a DVD and do something else at the same time, for example. HT has a negligible effect IMHO on being able to handle extra load, which is the main reason why you go with SMP.

Which one should I get to overclock?

The Intel Processor Finder has info on all available steppings and speed grades of all these CPUs. If you're unsure on what S-spec corresponds with what stepping or don't know what you have, check here.

The most popular is a 2.4/533 MHz Prestonia with a recent stepping, such as M0. If you buy recent stock new from a place like Newegg, you're pretty much guaranteed to get a good M0. I don't see a reason to go with 2.66 or higher- the 2.4 gives you the same overclocking ability with a better chance for a high FSB and a better price. There is a 2.4 with 1 MB L3 roaming around that looks attractive, and it doesn’t appear to have any less overclocking ability (I’ve seen results w/ it at 3.6 GHz).

LV chips have started to pop up, too. A very rare, but incredible deal has been the 1.6 GHz LV (low voltage) Xeon on a 400 MHz bus Socket 604. These are C1/D1 steppings at ridiculously low prices, meaning that you might be able to get 2x 3 GHz for really cheap. They aren't as good as M0 2.4s, though. These chips have now sold out, but if you find them used, well, you might be quite lucky. SL6XK is what to look for, these are the D1 steppings- they sell around $250 for a pair, which means $125 per CPU, which is incredibly good for their performance. Now, higher-speed LVs are becoming popular, as further binning to get to LV status may make these chips more overclockable.

The next big overclockers are 2.8/3.0 GHz Noconas and Irwindales, E0 and N0 steppings, respectively. They haven't emerged as much because of FSB limitations- Canterwood boards are generally limited to around 225 MHz and the only overclockable e7525 board so far has been the IWill DN800-SLI. Once FSB restrictions loosen up- as they eventually did for Canterwood- these guys will fly. I've personally gotten a pair of 2.8s to 3.6 GHz on stock cooling with stock voltage (takes a bit more than that for Prestonia), and that's barely scratching the surface.

Overclocking expectations (maxes with full tweaks and cooling):
  • C1- ~3.2 GHz if you're lucky
  • D1- 3.2 GHz, maybe a little higher
  • M0- roughly up to 3.6+ GHz

  • D0- ??? early steppings, avoid them
  • E0- 3.6 GHz+ Nocona
  • N0- 3.6 GHz + Irwindale

The Xeon Database further down this thread lists the overclocks of some of our members, from which you can get an idea of what to expect from a particular setup.

Parts of this post, especially cache, contributed by zachj
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Dec 7, 2002
Chipsets and Motherboards

What chipsets are available for Xeons?

These are just the AGP/PCIe desktop oriented chipsets, not the server ones.

Socket 603
  • i860
    • 400 MHz FSB
    • Dual-channel PC600/800 RDRAM
    • AGP
    • 64 bit 66 MHz PCI
    • E-ATX
The first P4 Xeon chipset. Solid, but none have any practical means of overclocking.

Socket 604
  • e7505
    • 400/533 MHz FSB
    • Dual-channel DDR266
    • AGP
    • PCI-X
    • ATX or E-ATX
    The first DDR workstation chipset for Xeons, also the first practically overclockable one. Capabilities vary greatly, from large integrated everything E-ATX to pared down ATX. Boards may or may not overclock traditionally.
  • i875P
    • 400/533 MHz FSB
    • Dual-channel DDR333
    • AGP
    • Southbridge SATA RAID
    • CSA Gigabit
    • Possible PCI-X
    • ATX
    The first fully-featured boards for enthusiasts and overclockers. Keeps all of Canterwood's capabilities, but the listed bus/RAM speeds are slower only because of slower stock FSBs for Xeons. All boards I know of overclock through the BIOS, and do it quite well.
  • e7525
    • 800 MHz FSB
    • Dual-channel DDR2-400 or regular DDR400 (depends on board)
    • PCI Express (including potential SLI support)
    • Southbridge SATA RAID
    • Possible PCI-X
    • ATX or E-ATX
    • NOT COMPATIBLE with non-800 MHz FSB CPUs (Prestonia, etc.), power differences will FRY your board
    This is the new chipset designed for Noconas/Irwindales. Early versions had errata, but current boards seem fine. The Asus NCT-D was supposed to be overclockable, but currently isn't, so the only overclockable, enthusiast motherboard of this class is the IWill DN800-SLI. Watch out for registered RAM requirements.

What motherboard makers have mobos for Xeons?

  • Intel
  • Supermicro- known for stability, they have NO BIOS tweaks.
  • Tyan- see Supermicro
  • IWill- Big enthusiast Xeon manufacturer #1. The first to come out with a BIOS-overclockable Xeon board, the first to come out with a BIOS-overclockable PCI-X Xeon board, the first with an enthusiast-class SLI Xeon board.
  • Asus- Big enthusiast Xeon manufacturer #2. The first to come out with a Canterwood Xeon board, the first to price boards to the enthusiast market.
  • MSI- kind of obscure, haven't seen them around at all but they do make Xeon boards.

What specific motherboards are good for overclocking?

  • IWill DPI533- e7505
    First Xeon motherboard overclockable from the BIOS. Has an AGP/PCI lock, but held back by chipset. Typical max FSB around 167, can go up to 180+
  • Asus PC-DL- i875P
    The first enthusiast Xeon motherboard. Overclockable via the BIOS, does 200+ FSB, but does not offer PCI-X. May or may not play well with Noconas.
  • IWill DH800- i875P with PCI-X
    Great overclocking ability, better power circuitry than PC-DL. Can do 200+, Nocona ready. Depending on who you talk to, the ultimate all-around Canterwood board.
  • Asus NCCH-DL- i875P with PCI-X
    Asus' answer to the DH800. Looks like it does every bit as well, but at a lower price. Has fewer FSB options compared to the DH800 (caps at 233).
  • IWill DN800-SLI- e7525, DDR2, dual PCIe 16x (one at 8x)
    The first of the next generation of enthusiast Xeon boards, originally the Alienware dual graphics board but now released to the general public. Requires registered DDR2, unfortunately. Overclockable, but no BIOS voltage adjustments and an FSB limit of 255 (for now).

A note about Canterwood overclockability

Xeon Canterwood boards are more sensitive and limited than their P4 brethren. Most boards max out around 225 MHz, although some people have managed to push their PC-DLs to around 250 MHz. Also, 4 GB or 4 sticks of RAM may noticeably hamper results in the 200+ range.

The PC-DL seems to be the overclocking winner, but it takes a lot of modding to get there and you sacrifice PCI-X. It all depends on what you need.


Dec 7, 2002
Other parts of a Xeon SMP System

I’m only dealing with components that might have special considerations because of the Xeon/dual platform. You can plan the rest of your own rig :).

What power supply should I use?

My guess at an absolute bare minimum PSU wattage would be around 450 watts. Don't listen to this. Do not skimp on your PSU, it doesn't cost much more and is definitely worth it!.

Here's what to look for:
  • EPS12V support- for some boards this might be optional, but be sure and do it anyway. Extra juice never hurts, and it is fast becoming standard.
  • SLI PCIe connectors- Some PSUs have specific plugs/configurations for dual PCIe graphics cards. This might be something of interest, either for future compatibility or for an SLI setup now.
  • 500+ Watts- pretty self-explanatory, make sure you have enough juice, especially for overclocking. Also note that these particular CPU cores can get quite power-hungry, and you have two of them.
  • Quality brand- this applies across the board with any system you build- make sure your PSU is a solid brand you can rely on.

Some models (see the EPS12V Thread courtesy of dicecca112):
  • Fortron 550 Watt EPS12v- One of the best, most well-reputed PSUs, and the best deal out there. I admit I'm biased- I've been running one for roughly 2 and half years, under large loads, with a slower fan than stock, and it has been rock solid. It's a keeper- I will run the thing into the ground.
  • Antec TruePower 2 550 Watt- SLI ready, dual fans that may help with volume/airflow- could be considered more refined than the Fortron. Extremely solid in experience and reputation.
  • OCZ PowerStream 600 Watt- Offers pre-modded LED fan and external fine-tuning for the voltage rails.
  • PC P&C Turbocool 510 XE- PC Power & Cooling is known as the ultimate in power supplies, with such standards as 1% voltage regulation. This is their EPS12V 500 watt unit (they are also deliberately underrated- this is actually 650 watts at peak).
  • PC P&C Turbocool 850 Watt- My jaw dropped when I saw this thing for the first time. The undisputed granddaddy of PSUs, the only thing that could separate me from my Fortron for my main rig. It's roughly double the length of a normal PSU, and significantly more expensive, but if you're looking for the biggest punch in just one package, this is it. Also SLI ready.

What RAM is good for a Xeon rig?

RAM isn't as critical in a Xeon rig because the FSBs are not above 250 MHz (DDR) or 300 MHz (DDR2) yet. In any case, watch out for:
  • Registered and/or ECC- some boards require this, some are optional, some don't take it at all. Watch out to see what the particular board's specifications are. Don't use registered ECC RAM to overclock if you don’t have to- it adds no tangible stability on these platforms IMHO (unlike 760MPX), is much more expensive, and might hamper your results (although DDR2 registered is reputed to OC far better than regular DDR registered).
  • Low-latency PC3200- Because your frequencies aren’t extremely high, you might as well squeeze out every bit of performance that you can get. Low-latency PC3200 gives you the flexibility of moderately high speeds while letting you get the most out of the typical 200 MHz with tight timings.
  • Low voltage when OC’ed- Remember that you don’t have as many nice BIOS options with these boards (you trade these for the power and ubercoolness), so watch for RAM that might love voltage. I believe people recommend TCCD or more recent chips over BH-5 because of this.
  • Amount- SMP and Xeon power may lead you to do more things at once, or end up doing more resource-intensive things than you did before. It might be worth it, depending on your usage, to invest in a little more RAM than usual to cover for this.
  • Dual-channel- Remember that the dual-channel Xeon chipsets require pairs of DIMMs. I'm not sure, but I don't think they even boot with only one stick of RAM- this may vary by chipset and board as well.

How can I use PCI-X slots?

64 bit or PCI-X slots are not PCI Express, they're an extension of normal PCI.

PCI bus speeds/bandwidths:
  • 32 bit 33 MHz- 133 MB/s
  • 32 bit 66 MHz/64 bit 33 MHz- 266 MB/s
  • 64 bit 66 MHz- 533 MB/s
  • 64 bit 100 MHz- 800 MB/s
  • 64 bit 133 MHz- 1.06 GB/s

Some uses are:
  • Storage adapters- SATA RAID, SCSI RAID, straight up SCSI, take your pick
  • NICs- Gigabit, dual gigabit, quad 10/100, quad gigabit :)
  • Firewire 800- an attractive alternative for external storage

I highly recommend investing in good storage along with the rest of your rig, because that's the first and most common place in your system where you feel speed or the critical lack thereof. Integrated SATA, like on the ICH5R, is very good, but you might want to consider secondary storage, like a RAID 5, or something like SCSI and small but fast 15K drives.

You can also use regular 32-bit PCI cards in these slots, as long as they have a 2nd slot toward the end with the bracket, giving the card 3 tabs overall. However, usually the whole 64 bit PCI bus will be brought down to 33 MHz speeds, so it'll cripple a high-speed card if you have both the 64 bit and 32 bit cards going at the same time (note: some RAID cards are 32 bit/66 MHz, which avoids this problem). 32 bit PCI cards in their own 32 bit slots are on a separate bus, and so they're a non-issue in their rightful slots.

A note on SLI and storage

The IWill DN800-SLI's only real shortcoming is the lack of PCI-X slots, if you need them. This is problem is somewhat alleviated if you use only one video card- the second PCIe slot can be used for a storage adapter. LSI makes a PCIe 8x version of their two-port U320 SCSI RAID controller, which because of the updated chip onboard is also their fastest controller, and Areca's line of SATA RAID controllers are in both PCI-X and 8x PCIe.

What are cooling options for Xeons?

Cooling in general is quite sparse on selection, but what's there performs well:
  • Stock Intel Windtunnel- these are high-quality heatsinks for the stock heatsinks that they are, and more recent ones are better built all-copper. They cool well, but the stock fan is a massively loud 60mm- its possible to hack an 80mm on, though, to fix this. Recent models aren’t really “windtunnels”, but just quite substantial copper stock heatsinks with much quieter fans- they're the best performing stock heatsinks I've encountered.
  • Dynatron H67- a solidly designed all-copper heatsink whose little brother was tested by Overclockers.com and performs well. 70mm is easy to mod to 80mm, or even 92mm if you offset the fans with shrouds to clear the adjacent socket. The H67 mounts Nocona, the H65 does the older retention.
  • Coolermaster E3W-N7WSS-04- Similar to the Dynatron, looks a tad bit beefier.
  • Coolermaster E3W-NPTXS-04- Massive heatpipe designed for passive cooling. Does very well on an overclocked setup with quiet fans.
  • Swiftech MCX-603/4(V)- the Xeon versions of the typical Swiftech pin-fin heatsink. The non-V is the old style, the V version is the flower style. I can personally attest to the quality of these sinks, they're not flimsy like the Windtunnel fins and they let me cool my overclocked 3.2 GHz quietly.
  • Thermalright SI-9XV- their latest heatpipe design ported to Socket 604. Looks very promising, perhaps will take the Xeon aircooling crown.

Both Swiftech and Danger Den now offer waterblocks for Xeons, too.

Noconas have a different retention system, supposedly to support increasing heatsink weights. Instead of mounting hardware being screwed into the motherboard, it attaches through significantly enlarged motherboard holes to a backplate that's secured to the case. My DH800 backplate interfered with my Lian-Li's mounting system, so I fudged it with S603 mounting hardware that had individual backplates per CPU- the problem is that regular standoffs are designed to be screwed through the backplate, but Lian-Li's standoffs don't screw in to the motherboard tray, they snap into square holes. The DN800-SLI comes with hardware that solves this issue.

Beware of the spacing between CPUs and the AGP slot. My Swiftechs are almost touching between CPUs, and come very close to the AGP slot. I tried installing a Zalman heatpipe on my video card, but it would not make the tight clearance between the back of the card and the bottom edge of the heatsink. Of course, this depends on the heatsinks you use, but it is a very important point that's easy to overlook.

A note on cases

If, for some reason, you're using an E-ATX motherboard (none of the big overclockers mentioned so far are E-ATX), watch out for cases. Some cases that claim to be E-ATX compliant, such as the Antec mid-towers, *might* have issues with components, like DIMMs, clearing the 5.25 bays. e7525 boards place the CPUs at the far right of the board, which now makes this a critical issue for all form factors. Make sure your case has ample clearance.

Which operating system should I use?

The biggest thing OS-wise for dual Xeons are the 4 total "CPUs" you'll get with HT on each CPU. Windows XP Pro and 2003 support SMP and can properly recognize and run threads for the dual HT CPUs, so these OSes are the best Windows option for Xeons. They'll give you 4 CPU usage graphs in Task Manager, so you can hallucinate about 4-way, too ;). Windows 2000 won't recognize the HT at all, so you'll lose the performance boost that HT could give. Depending on the application, that could mean something.

Anything Linux 2.4.x or greater will be more than fine on Xeons, as they can handle the HT quite well.
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Dec 7, 2002


Socket layout in next post due to image limit

Pin Manipulation

Specific arrays of pins determine a CPU’s default voltage and FSB- unique combinations of 0 or 1 per pin each correspond to a different setting. 0/L is the presence of current through a pin, 1/H is its absence. So, to change the setting that the pins create, we manipulate the flow of current through each pin, either adding it or removing it, to make a different combination for what we want.

To change a pin from 0 to 1, removing current, insulate it. Wire insulation is a reversible, safe way to do this- the insulation from 30-gauge wrap wire should work well. Strip a small section, and use tweezers or something similar to put it over the pin.

To change a pin from 1 to 0, adding current, do a U-wire mod, which “joins” the pin to another pin.
  • Choose an adjacent pin with current- either another of the same group with a default 0, or a power or ground pin.
  • Take a small strand of wire- preferably quality copper wire from a strand of audio cable- and clip off a short length. Form it with needle-nose pliers or tweezers into a narrow “U” shape.
  • Place the wire in the CPU socket. One end goes into the hole for the pin you’re changing, the other end goes into the hole for the pin that you chose in the first step. Push the U loop as far down as it can go- if it sticks up, remove it and trim its length. It must be as low as possible to allow for CPU installation.

Both mods will make CPU insertion more difficult. You may have to push to successfully install it- make sure you go firmly but slowly, pushing perpendicular to the motherboard, so that you don’t accidentally bend any pins. If it’s too hard, you may have to find thinner wire/insulation.

Volt Mods

Because of the lack of voltage adjustments in various motherboards, whether they have none at all or too restricted a range, Xeon volt mods are very important. Because of the ugly results of overvoltage, watch your levels and don’t go too high. 1.65v is a good maximum for Prestonias, 1.55v for Nocona/Irwindale.

The VID pin group controls default voltage. Their actual pins are (Prestonia, then Nocona):


Use the chart below to determine proper mods (again, Prestonia, then Nocona). How to use the chart:
  • Find the combination that matches your particular CPU’s default voltage. Your default can be found on the bottom of your CPU, next to the Sspec, packaging plant, and other printed information.
  • Find your desired voltage level on the chart, and its VID combination. Figure out which pins change and how, and then do the appropriate pin manipulations mentioned above.



The BSEL mods, as I originally wrote about here way before the spiffy Canterwood generation, change how the motherboard senses the CPU's default FSB. This lets you fool a motherboard into thinking a 400 MHz FSB CPU is actually a 533 MHz FSB CPU, etc. In addition to this allowing you overclock in a "non-overclockable" board with no BIOS tweaks, like back in the dark ages :), it may also allow you to unlock new FSB options. This is particularly the case in the DH800 v1.0 and perhaps others, where FSBs above 200 MHz are available only if it detects a 200 MHz FSB CPU.

Remember that this mod depends on the motherboard detecting the change and knowing what to do with it. Your motherboard must support the FSB that you’re modding to.

The BSEL pins:


The BSEL settings:


It works just like the VID pin mod: find your default setting, find your target setting, and make the appropriate changes.

The 604th Pin

In case you're wondering, the 604th pin of Socket 604, AE30, does nothing. That means you can snap it off and throw the CPU in a Socket 603 board (if not a Nocona) or do whatever you want. Why, I don't know...


  • The DH800 v1.0's BIOS only allows up to a 197 FSB with 533 MHz CPUs. Doing the 533->800 BSEL mod will "unlock" BIOS options above 200.
  • Kikia mod- This mod creates a jumper that will set the DH800's default FSB, like the BSEL mod. It can also add a 166 MHz default that seems to be the most favorable to overclocking and allows for stable CAS 2. v1.2 of this board has this FSB jumper pre-installed.

  • The Asus Dual Xeon Resource Site is dedicated to everything for Asus Xeon motherboards. The PC-DL in particular has a number of on-board volt mods for CPU core, drooping issues, northbridge, and RAM, along with a modded BIOS or two.
    Contributed by disk11.


I have a request pending with the author of Clockgen to add this board to the program. Hopefully, that will remove the silly 255 FSB ceiling- certainly the clockgen on the board is capable of more. This is the foundation of my revamped personal rig, and I’ll be pushing it as far as I can, and then reporting back, of course. No mods are necessary so far (unless you’re running something like a 3.6 with the high multi), but once the FSB restriction is gone that will change :).
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Dec 7, 2002
Xeon Overclocking Results

Post your overclocked Xeon setup so that we can generate a mini-database, kind of like in other CPU threads.

Format: CPU, speed (multi * FSB), voltage, stepping, S-spec, mobo
Cooling and any mods

2x Xeon 2.4 GHz/533 MHz, @ 3.4 GHz (18 * 189), 1.575v, M0, SL72D, IWill DH800
2x Swiftech MCX-603V, 2x 80mm Panaflo H1A

Member | CPU | Overclocked MHz | Voltage | Stepping Info | Mobo | Cooling/Notes

mateo | 2x 2.4/533 | 3.4 GHz (18*189) | 1.575v | M0, SL72D | IWill DH800 | 2x Swiftech MCX-603V + 80mm Panaflo H1A

Twin_Turbo | 2x 1.6/400 LV | 2.4 GHz (16*150) | 1.3v | C1, SL6GV | Asus PC-DL | 2x Intel Windtunnel

Yitsan | 2x 2.4/533 | 3.31 GHz (16*207) | 1.5v | C1, SL6NQ + D1, SL6VL | Asus PC-DL | 2x Swiftech MCW5002 + Moosemod

DonP | 2x 1.6/400 LV | 2.66 GHz (16 * 166) | 1.55v | C1 | Asus PC-DL | 2x Intel Windtunnel

earlmred | 2x 1.6/400 LV | 2.64 GHz (16 * 165) | 1.6v | C1 | Asus PC-DL | 2x Intel Windtunnel, Moosemod (133-165 MHz), U-Wire Volt Mod

Twin_Turbo | 2x 1.6/400 LV | 2.74 GHz (13 * 210) | 1.3v | C1, SL6GV | Asus PC-DL | 2x Intel Windtunnel

StreetSam10 | 2x 2.4/533 | 3.3 GHz (15*220) | 1.5v | M0, SL73L | Asus PCH-DL Deluxe | Asetek Xeon Waterblocks | moosemod to 200-233 | Mem 1:1

StreetSam10 | 2x 2.0/400 LV | 3.1 GHz (19*163) | 1.6v | D1, SL6XL | Asus PC-DL | Asetek Xeon Waterblocks | u-wire to 1.6V and moosemod to 133-165 | mem 4:5

audioaficionado | 533/2.4 Prestonia | 220MHz/3300MHz | 1.5vcore | M0 | DH800 | CoolerMaster E3W-NPTXS-04 heatpipes | 35°C/55°C I/L

David Coleman | 1.6LV D1's | 16x213 =3408 | 1.56v | SL6XL | PC-DL 1.05 | AL/CU IWT's w/60x25mm intel fans and q-fan

mbentley | 2 x 3.2 noconas e0 | 16x225 = 3600 | 1.4v | sl7td | ncch-dl | 2 x swiftech mcx603-v; both with antec all clear pro 80 mm fans

mbentley | 2 x 2.4 prestonias c1 | 18x156 = 2808 | 1.5v | sl6nq | ncch-dl | 2 x coolermaster E3W-NPTXS-04; with antec all clear pro 80 mm fans attached to the sides

Tualatin | 2 x 2.66GHz/533 | 2.8GHz (14 x 200) | 1.5V | C1, ES | IWill DH800 | 2 x Intel Wind Tunnel (from 3.2GHz/2MB), Mem 1:1

Tyrinon | 2x 1.6LV/400 | 3.01GHz (14x215) | 1.5v | D1, SL6XK | ASUS PC-DL Deluxe Rev. 1.05 | AL/CU IWT's w/60x38mm Intel fans | Work in progress (as time permits)

Pickles | 2x 1.6/400 LV | 14x200 =2800 | 1.60v | C1 SL6GV | PC-DL 1.05 | AL/CU IWT's w/60x25mm intel fans (flipped)

Thideras | 2x 2.8/800 nocona | 3.2Ghz (14*230) | 1.25V | e0, 0F14H | IWill DN800-Sli | custom water cooled
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Dec 7, 2002
Thanks for the compliment and the link...missed that one with everything else I've missed from here, arg. That's been added in.
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Feb 25, 2004
Thanks for the compliment and the link...missed that one with everything else I've missed from here, arg. That's been added in.

wasn't that hard to miss it, took me 10minutes to find the freaking thing.

and oh yes STICKY!!!!!


Dec 7, 2002
Thanks everyone, it has been stickied so we don't need the votes anymore ;), but they are appreciated.

What we need now is a whole bunch of OCer input on their own rigs, build up the results a bit.


Aug 24, 2005
mateo said:
Xeon Overclocking Results

Hi everyone, can you add these to the list, cheers.

StreetSam10 | 2x 2.4/533 | 3.3 GHz (15*220) | 1.5v | M0, SL73L | Asus PCH-DL Deluxe | Asetek Xeon Waterblocks | moosemod to 200-233 | Mem 1:1

StreetSam10 | 2x 2.0/400 LV | 3.1 GHz (19*163) | 1.6v | D1, SL6XL | Asus PC-DL | Asetek Xeon Waterblocks | u-wire to 1.6V and moosemod to 133-165 | mem 4:5
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Sparkomatic Moderator
Apr 29, 2002
Member | CPU | Overclocked MHz | Voltage | Stepping Info | Mobo | Cooling/Notes

audioaficionado | 533/2.4 Prestonia | 220MHz/3300MHz | 1.55vcore | M0 | DH800 | CoolerMaster E3W-NPTXS-04 heatpipes | 35°C/55°C I/L

Complete specs:
Iwill DH800, OCZ4002048PFDC-K 2.5-3-3-8-1t, dual Prestionia Xeons 2.4 M0, CoolerMaster E3W-NPTXS-04 heatpipes, Antec 550W TP EPS12V, AMS gTower CF1006, XFX nVidia GF6600GT dual DVI, WD 74Gb Raptor & 250GB SATA, NEC 3500A/G DL DVD±R/W

Edit: fixed obviously incorrect vcore. That's what I get for trying to type in a hurry on a non ergonomic keyboard at work :p
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David Coleman

Oct 11, 2003
Gainesville, FL
Member | CPU | Overclocked MHz | Voltage | Stepping Info | Mobo | Cooling/Notes

David Coleman | 1.6LV D1's | 16x213 =3408 | 1.56v | SL6XL | PC-DL 1.05 | AL/CU IWT's w/60x25mm intel fans and q-fan

I'm working on stability of that 213FSB...but it's rock solid stable at 210.

Temps never get above 50 under load once q-fan kicks those fans up :)


Dec 7, 2002
Updated, now that I've had time to actually breathe in college.


Gloriously Lead, Overclockix Chief Architect
Sep 26, 2002
Indianapolis, IN
here are my overclocking results

mbentley | 2 x 3.2 noconas e0 | 16x225 = 3600 | 1.4v | sl7td | ncch-dl | 2 x swiftech mcx603-v; both with antec all clear pro 80 mm fans

mbentley | 2 x 2.4 prestonias c1 | 18x156 = 2808 | 1.5v | sl6nq | ncch-dl | 2 x coolermaster E3W-NPTXS-04; with antec all clear pro 80 mm fans attached to the sides