The i815EP reportedly had lower memory bandwidth than the i440BX but was a solid choice for that era, though admittedly being more of a transitional product.
I was compelled to upgrade to an Abit ST6 from a BH6 sporting those respective chipsets because the board could not supply enough AGP power for even a Radeon 7500 (it varied). If cards were supplied with their own power plugs at that time then the BH6 could have had an even crazier long upgradeabilty (for me) since the CPU range was relatively "unlimited".
I started with a Mendocino C300A @ 464 and went to a Coppermine 533A @ 825 and even flirted briefly with a rare Coppermine P1100 @ 1234 but right about the time that a viddy upgrade became necessary from the likewise legendary Radeon LE TVO (7200), a Tualatin socket adapter (or mod) was available to extend the compatabilty right up to the C/P 1400's!
But as said, it was an ST6 for me... although the good thing was that during the time between discovering the 7500 on the BH6 was no go and actually doing the swap, I was able to get an 8500 instead to complement the new Tualatin C1100A @ 1500. The 8500 had more longevity anyway and indeed was yet another such legendary component.
Please excuse my nostalgic ramblings
