Hi
What i meant was, I had a Gigabyte S478 board, 8S661FXMP-RZ, with DDR333 and a Celeron CPU.
The RAM died and I discovered that I could only use the new DDR400 RAM with an FSB800 CPU.
The board would not post with DDR400 and Celeron FSB533 CPU... no amount of BIOS fiddling could get the 533FSB chip to work with DDR400 RAM.
I had to use DDR333/DDR266 with that FSB533 CPU on this board.
A 2nd hand P4 FSB800 chip sorted this out.
I ended up having to match CPU FSB on this machine.
What i meant was, I had a Gigabyte S478 board, 8S661FXMP-RZ, with DDR333 and a Celeron CPU.
The RAM died and I discovered that I could only use the new DDR400 RAM with an FSB800 CPU.
The board would not post with DDR400 and Celeron FSB533 CPU... no amount of BIOS fiddling could get the 533FSB chip to work with DDR400 RAM.
I had to use DDR333/DDR266 with that FSB533 CPU on this board.
A 2nd hand P4 FSB800 chip sorted this out.
I ended up having to match CPU FSB on this machine.
Not this one. In auto mode it selects optimum (the fastest) RAM speed based on SPD. Not sure if found two different modules; it picks up the slower one or just looks for one slot. Even if picks up the slower one, what happen if DDR400 has incompatible timing in DDR333 mode?
Lastly, old mobos don't like high density chips. Typical example is i440BX chipset which detects such modules as having half capacity. And if you mix it with other modules it appears to work, but memory test fails or simply hangs due to the conflict on the memory bus. Only very early 256MB modules work on these boards, it was pain in ass sometime ago to find a right memory for my Asus P2B.