Conroe Buying Guide: Feeding the Monster

Intel 975XBX
Basic Features

Intel 975XBX
Market Segment	High-End/Enthusiast
CPU Interface	Socket T (Socket 775)
Chipset	Intel 975X + ICH7R
CPU Support	Core 2 Duo, Pentium D, Celeron D, Pentium XE, LGA-775 based Pentium 4
Thermal Design	8-phase power Fan-less (Passive) Cooling
Front Side Bus	1333 / 1067 / 800 / 533 MHz
Host Burn-In Mode	0 - 50% (in 1 percent increments)
Memory Speeds	Default, DDR2 333, 400, 533, 667, and 800MHz
PCI Bus Speeds	Default, 40.00MHz
PCIe Speeds	Default, 101.32, 102.64, 103.96, 105.28, 106.6, 107.92, 109.24MHz
Set Processor Multiplier	6 to 40 (Depends on CPU) in 1X increments
Core Voltage	Default, 1.2750V to 1.6000V (in 0.0125V increments)
DRAM Voltage	Default, 1.80V, 1.90V, 2.00V, 2.10V, 2.20V
MCH Chipset Voltage	Default, 1.525V, 1.600V, 1.650V, 1.725V
FSB Termination Voltage	Default, 1.271V, 1.333V, 1.395V
Multi-GPU Option	CrossFire (2 X8 PCIe)
Memory Slots	Four 240-pin DDR2 DIMM Slots Dual-Channel Configuration Unbuffered ECC/non ECC Memory to 8GB Total
Expansion Slots	2 PCIe X16 (operates in 1X16 and 1X8 or 2X8 mode) 1 PCIe X16 (operates in X4 mode) 2 PCI 2.3
Onboard SATA	4 SATA 3Gb/s by ICH7R
Onboard IDE	1 UltraDMA 100/66/33 (2 Drives) by ICH7R
SATA/IDE RAID	Intel ICH7R: (4) x SATA 3Gb/s RAID 0, RAID 1, RAID 5, RAID 10, and Intel Matrix Storage technology Silicon Image SiI3114: (4) x SATA 1.5Gb/s RAID 0, RAID 1, RAID 0+1 (operates on PCI bus)
Onboard USB 2.0/IEEE-1394	8 USB2.0 ports by ICH7R 2 IEEE 1394a FireWire Ports by TI TSB43AB23
Onboard LAN	Intel 82573L PCIe X1 Gb LAN
Onboard Audio	Sigmatel STAC9221D, 8-channel capable HD Audio Codec featuring Dolby Master Studio technology
Power Connectors	24-pin ATX 8-pin EATX 12V 4-pin Molex Plug
Back Panel I/O Ports	1 x PS/2 Keyboard 1 x PS/2 Mouse 1 x Parallel 1 x Serial 1 x Audio I/O Panel 1 x Optical S/PDIF Out Port 1 x Coaxial S/PDIF Out Port 1 x RJ45 4 x USB
BIOS Revision	Intel 6/20/2006

The Intel 975XBX, known by most as the BadAxe, was the first motherboard to officially support Core 2 Duo. AnandTech reviewed the board in January 2006 at Intel D975XBX: Intel brings their BadAxe to Market, but that early board was not really compatible with the just-launched Core 2 Duo processors. For Conroe compatibility the BadAxe must be Revision 0304 or later.

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Since BadAxe was the only Conroe choice during much of the developmental testing, it quickly gained a list of user modifications that seems almost endless. The 975XBX is an Intel board that is actually capable of being overclocked and that actually has some decent adjustment options in the BIOS. This is not something you expect from Intel boards in the past, but it has definitely been an increasing part of Intel's top-end offerings.

The current BadAxe board has a few improved options in the BIOS, like overclock options to 50% instead of 30%, but it is otherwise still the exact same board AT reviewed this past January. For more information on the board please go to the AnandTech BadAxe review.

Basic Performance

While Intel does provide options that enable overclocking BadAxe, they still have a lot to learn about producing a motherboard for the Enthusiast. If you set a bad overclock on the BadAxe the board will NOT recover gracefully as ASUS, Gigabyte, DFI, and other Enthusiast boards normally manage. If you try to do some serious overclocking on this board you will quickly learn where the clear CMOS jumper is located and how to pop out the battery. In a failed OC on BadAxe, clearing CMOS and removing the battery are the only way to recover and reboot. This makes overclocking with BadAxe a very frustrating experience.

It is perhaps best to view the Intel 975Xbx as an incredibly stable motherboard built to last a very long time, as Intel motherboards normally are. It also allows overclocking, but the Intel BadAxe is not really set up for the kind of overclocking serious overclockers demand. It's is a difficult board to bring back from a failed OC.

Intel motherboards remain the standard against which others are measured in stock performance, and BadAxe is a fast and stable board running Core 2 Duo. It is not, though, a speed demon compared to the ASUS or other solid 975X motherboards as we have sometimes seen from Intel in the past.

Those who could care less about overclocking, or who only want to overclock modestly will likely be very pleased with BadAxe performance. So will overclockers who only want to overclock with multipliers since BadAxe supports the unlocked X6800 processor with multipliers both up and down from the stock 11x.

Overclocking

Intel 975XBX Overclocking Testbed
Processor:	Intel Core 2 Duo E6700 Dual Core, 2.67GHz, 4MB Unified Cache 1066FSB, 10x Multiplier
CPU Voltage:	1.395v (default 1.2V)
Cooling:	Tuniq Tower 120 Air Cooling
Power Supply:	OCZ GameXstream 700W
Memory:	Corsair Twin2X2048-PC2-8500C5 (2x1GB) (Micron Memory Chips)
Hard Drive	Hitachi 250GB 7200RPM SATA2 16MB Cache
Maximum OC: (Standard Ratio)	325x10 3250MHz (+22%)

Perhaps because overclocking was so difficult compared to other boards in this Buyers Guide we only managed to reach a 22% overclock with the E6700, or 3.25GHz. We reached a similar 21% OC with the 2.93GHz X6800, reaching a stable 3.55GHz.

Others who have modified the BadAxe board, or who have a much greater tolerance to OC pain than we do, have reached much higher overclocks than we reached in our tests. However, two editors, with different boards and processors, reached almost the same results with BadAxe.

If you want to run your 2.93 or E6600 at 4GHz without a huge hassle then choose another motherboard, like the ASUS P5W-DH Deluxe. If you want to run almost forever with no problems then choose BadAxe. You can even take BadAxe to stratospheric overclocks, but that requires hardware modifications.