X48 Motherboard Comparison

BIOS And Overclocking

Swipe to scroll horizontally
BIOS Frequency and Voltage settings (for overclocking)
FSB Frequency100 - 700 MHz (1 MHz)
Clock Multiplier AdjustmentYes
DRAM FrequencyFSB x 1.0, 1.2, 1.25, 1.33, 1.5, 1.6, 1.66, 2.0
PCIe Clock90 - 150 MHz (1 MHz)
CPU Vcore0.50000- 1.6000 - 2.35 Volts (0.00625/0.05 Volts)
CPU FSB Voltage1.20 - 1.55 Volts (0.05 Volts)
Northbridge (MCH)1.25 - 1.625 Volts (0.15 Volts)
Southbridge (ICH)None
DRAM Voltage1.80 - 3.35 Volts (0.05 Volts)
CAS Latency Range
tCAS: 4-11; tRCD: 1-15; tRP: 1-15; tRAS: 1-63

Carried over with few (if any) changes from the previous X38-DQ6, the X48-DQ6 BIOS provides broad voltage and frequency ranges to meet the demanding needs of most overclockers.

The CPU Front Side Bus clock rate ranges from 100 to 700 MHz, well beyond the capabilities of the chipset. Even with extreme cooling and voltage modifications, top overclockers rarely exceed 600 MHz FSB on any motherboard.

Memory ratios are listed as DDR2 data rate to FSB clock rate, so each setting appears twice as high as the actual multiplier. All ratios are available at all bus speeds, but a handy chart on the side appears when selecting a data rate, to tell builders which northbridge bootstrap applies. Choosing the "wrong" bootstrap can cause the system to become unbootable at otherwise achievable frequencies, but using the chart to find the correct ratios can prevent these issues.

The CPU core voltage is available from 0.500 to 1.600 volts in ultra-fine 6.25 millivolt steps, while processors that require even more voltage can only be adjusted in 50 millivolt steps. The higher voltage levels generally apply only when overclocking older Pentium D processors, though we have seen a few "extreme overclockers" with equally extreme cooling configurations use insane voltage levels on Core 2 processors.

DRAM voltage ranges up to 3.05 V in 50 mV steps, but even the most avid overclocker probably won't need more than 2.60 V for excessively-cooled DDR2.

While CPU core voltage is listed in actual values, the remaining voltages are labeled as "over stock" levels. Determining the actual voltage chosen requires one to know what the stock voltage was supposed to have been.

We chose 1.60 volts core and the +0.30 volt FSB setting, reaching 4023 MHz on our Core 2 Duo E6850. Lowering the CPU core multiplier to 6x allowed us to reach an FSB limit of 538 MHz.

Thomas Soderstrom
Thomas Soderstrom is a Senior Staff Editor at Tom's Hardware US. He tests and reviews cases, cooling, memory and motherboards.
  • Help please.Can this board be configured with the first two (SATA) HDs mirrored and the other drives JBOD? Thank you in advance.
    Reply
  • oblivionspell
    Great review, very detailed and informative. But I must say that either you were lucky that your X38 P5E3 Deluxe came with a better-than-average chipset or that I wasn't so lucky and got a malfunctioning one.

    I have an Asus Maximus Formula which is, as you know, the Republic of Gamer's solution for the X38 and recently bought a Patriot Extreme Performance 1150mhz PC2-9600. Whenever I try anything above 1020mhz for the RAM my PC reboots; the higher it is the less time it takes to do it. At 1020mhz it'll only reboot if I run something more demanding like 3dMark06 or any new game, at 1100mhz it'll barely show the Windows loading screen then reboot, above 1120mhz it'll not even load windows and freeze. But in every case it boots up fine.

    The Asus forums are full of users who can't get stability in any way with >=1066mhz ram on X38 boards. A selected few have come to accomplish it however, which leads me to think those were the lucky ones who got the good shipment, like you. The Patriot forums are the same, X38 users can't get their system stable with RAMS over 1066 or not even that.

    Maybe that X48 "official" support is something to consider, it might be the fix to the X38 we users are looking for. Even if it's only to make sure it'll run RAMs at >=1066mhz, it's good enough already.
    Reply
  • oblivionspell - Have you tried manually setting your RAM voltage to the correct value for the performance setting(s)?

    I had to do this on my Asus Crosshair, even though EPP is supposed to take care of it for you. Without manually setting the voltage, I had memory corruption and crashes, but could use the non-EPP mode. With the voltage bumped to the correct 2.1V,
    the EPP modes work perfectly.
    Reply
  • Crashman
    oblivionspellGreat review, very detailed and informative. But I must say that either you were lucky that your X38 P5E3 Deluxe came with a better-than-average chipset or that I wasn't so lucky and got a malfunctioning one.I have an Asus Maximus Formula which is, as you know, the Republic of Gamer's solution for the X38 and recently bought a Patriot Extreme Performance 1150mhz PC2-9600. Whenever I try anything above 1020mhz for the RAM my PC reboots; the higher it is the less time it takes to do it. At 1020mhz it'll only reboot if I run something more demanding like 3dMark06 or any new game, at 1100mhz it'll barely show the Windows loading screen then reboot, above 1120mhz it'll not even load windows and freeze. But in every case it boots up fine.The Asus forums are full of users who can't get stability in any way with >=1066mhz ram on X38 boards. A selected few have come to accomplish it however, which leads me to think those were the lucky ones who got the good shipment, like you. The Patriot forums are the same, X38 users can't get their system stable with RAMS over 1066 or not even that.Maybe that X48 "official" support is something to consider, it might be the fix to the X38 we users are looking for. Even if it's only to make sure it'll run RAMs at >=1066mhz, it's good enough already.
    It's just a matter of having the right RAM and using the correct timings and voltage. All X38 and X48 motherboards that support DDR2 memory can run DDR2-1066 speeds with stability, so long as the RAM is set up right in BIOS.
    Reply
  • "Inside, users will find a GUI based on the Smart Common Input Method (SCIM) platform."

    This is not accurate. SCIM is an "input method" -- a scheme for entering internationalized text. Not sure what the GUI is really based on. GTK2, maybe?
    Reply
  • Crashman
    "Inside, users will find a GUI based on the Smart Common Input Method (SCIM) platform."

    This is not accurate. SCIM is an "input method" -- a scheme for entering internationalized text. Not sure what the GUI is really based on. GTK2, maybe?

    I see your point, but that's the same arguement as "Windows 98SE is a GUI based on DOS". Which is innacurate only in wording. It would be better to say "Windows 98SE is a GUI for DOS".

    So, you'd be happier to read "Users will find a GUI for the Smart Common Input Method (SCIM) platform" correct?
    Reply
  • chill70
    It's not only the wording. SCIM is not an operating system, so even your example is not analogous (won't even mention that DOS and Windows are separate operating systems with distinct kernels, etc).

    This statement is as correct as saying Vista has a GUI based on a 105-key keyboard.

    SCIM is an input method platform independent on the GUI. GTK GUI is an widget toolkit, independent on SCIM (although they *may* used each other). Neither is "based" on the other.

    If you want to emphasize that the Express Gate supports users of many different languages and nationalities you can mention that the GUI USES SCIM.
    Reply