We have a clear winner, but not an awardable one: the Asus P5E3 Premium was the only motherboard in this comparison to pass all of our testing criteria, so it wins by default. It has a good add-in RAID controller, a sufficient onboard audio solution, and most importantly, stable support for four memory modules.

On the other hand, anyone who has second-guessed themselves concerning the overall value of the X48 Express probably shouldn’t have bothered to do so. Our X38 Express motherboards overclocked just as well, and all of them supported Intel’s latest FSB-1600 - the reason for which the X48 was released. A few of our own editors would claim that the X48 Express should be the default choice for FSB-1600 desktop processors, because nothing is certain in the world of overclocking, but we’ve yet to present any evidence of an X38 motherboard that was not perfectly stable at speeds beyond FSB-1600.

If the P5E3 Premium’s win was due to the superiority of the X48 Express chipset, we’d expect to see similar improvements across all X48 models. One could point to the higher memory stability of the P5E3 Premium - when compared to the P5E3 Deluxe - as proof of the X48 Express chipset’s superior stability. But minor differences between PCB revisions 1.03G and 2.00G between the two models are more likely responsible for this benefit. Retail buyers should expect the latest PCB version to be applied to either model.

One might also expect that the P5E3 Premium BIOS is optimized for added high-FSB stability, rather than the best performance. But even if that’s the case, Asus is perfectly capable of supplying a BIOS that’s "optimized for performance" using the FSB-1333 bootstrap and "optimized for stability" using the FSB-1600 bootstrap.

A higher "validated" speed is no guarantee of increased clock speed potential. The idea that the X48 Express is better than the X38 Express in the same way that a Core 2 Duo E6850 is better than a Core 2 Duo E6750 can be shot down by the fact that our E6850 doesn’t overclock as far as our E6750.

So what do motherboards featuring the super-upscale X48 Express chipset cost? Nobody knows with certainty, since they haven’t been distributed yet. We expect the price premium to drop to around $20 once availability becomes consistent, but early buyers can expect much higher premiums at first release for what are, electronically, the same products as the X38-Express models on which these are based. Current pricing for the X38 versions of this comparison’s motherboards are approximately $350 for the P5E3 Deluxe WiFi-AP @N Edition, $285 for the rest....if you can find them. The MSI X38 Platinum price for example is an estimate, as even this older version of the X48 Platinum is "out of stock" everywhere we looked.

If X38 Express motherboard prices remain consistent for X48 Express versions, buyers who only plan to use two memory modules could find better value in the second-place Gigabyte GA-X48T-DQ6. But at these prices we can’t imagine too many buyers will be willing to pay even more for an X48 Express Northbridge, and manufacturers may be waiting for X38 prices to drop a bit before shipping X48 derivatives.

In the end, the difference between the X48 and X38 Express is at best 98% marketing and 2% validation. Buyers who constantly find themselves among the unlucky few should consider the X48 Express as insurance against high-FSB stability issues, but everyone else could potentially find better value in the X38 Express.