Overclocking/compatibility

New packaging

With the debut of the Athlon XP, AMD has also moved to its new organic pin grid array packaging. This packaging has been used by Intel for quite some time in its flip chip processors, and lowers production costs for AMD. The ceramic material previously used to make the packaging has been replaced by fiberglass. According to AMD, the implementation is similar to that used in printed circuit boards. We noticed that the new packaging is considerably lighter and slightly thinner than AMD's previous packaging used with Thunderbird.

A closer look at the core

If you look up close, you can see that the bridge configuration has changed completely with the new Palomino core. Previously only seven bridges were located on the surface of the packaging; with the new core eleven bridges are present. As you can see, AMD has shipped these processors with the L1 bridges in the open (locked) position, only bridges L6, L7, and L8 are closed. Recently AMD has shipped their faster processors unlocked by default, making clock multiplier adjustment a simple process if the motherboard supports it -- no physical adjustments to the processor are necessary.

With the new packaging, simply connecting the bridges with a pencil will not close the bridges as AMD has employed a new method of cutting them. OC-AthlonXP.com is a new website which offers tips for unlocking the clock multiplier, but so far has had limited success. It appears motherboards that utilize jumpers to adjust the clock multiplier only offer limited adjustments, while jumperless boards offer the full complement of clock multipliers to play with. It will be interesting to see what types of solutions will and won't work. A conductive pen may be enough to close the bridges, Plycon also offers trace tape for accomplishing the same purpose.

Heatsink support

In terms of heatsink compatibility, Athlon XP processors should work perfectly with existing Socket A heatsinks. As we mentioned above, the new packaging is slightly thinner than its predecessor, but AMD's validation unit hasn't run into any problems securing Athlon XP to the motherboard with any of today's heatsinks. Since the chip runs cooler, heat shouldn't be as large of an issue as it was with Thunderbird.

Motherboards

So far, AMD's validation unit has approved the following motherboards for use with Athlon XP:

	Chipset	BIOS Revision
ASUS A7V266 rev1.05	KT266	1002 Beta 05
Biostar M7VIB rev1.0	KT266	N/A
Biostar M7MIA rev1.1	IGD4	MIA0927F
ECS K7S5A rev1.1	SiS 735	010921
ECS K7VTA3 rev1.0	KT266	1.11A
FIC AD11 rev1.2	AMD-760	ABA419
Gigabyte GA-7DX rev4.0	AMD-760	F5D
Gigabyte GA-7ZMMH rev2.0	KM133A	F4B
MSI MS-6340M rev5.0	KM133A	N/A
MSI MS-6380 rev1.0A	KT266	Ver 1.50
MSI MS-6330 rev3.0	KT133A	Ver. 3.0

We've been told that dozens of additional motherboards are still being run through AMD's validation process, and will be added to the list shortly. Unfortunately however, there will be some Socket A motherboards that will never make this list. We've heard through unconfirmed sources that inferior components will prevent some motherboards from working with Athlon XP, while others may not be validated for the higher clock frequencies.

Then there's the case of other motherboards that may work fine in typical everyday use, but just don't live up to the qualifications of AMD's validation unit. These motherboards are all pushed to the limit before receiving AMD's seal of approval, we've been told that some motherboards may work fine with the processor in the average use that many of our readers put their systems through, but under heavy load in harsher environments, reliability becomes an issue. The motherboards that fall in this gray area aren't officially approved by AMD, but may work fine for end users.

In any case, as usual we recommend sticking to a motherboard that has been approved by AMD. As usual, AMD will make updates to the list as new motherboards have been approved. We've noticed that unlike traditional "approved" lists, AMD's validation unit keeps their list very up to date. Updates are made as soon as a product is validated.