Is ECC PC800 RDRAM compatible with Non ECC PC800 RDRAM?

[nzgfxguru]

I bought some PC800 ECC RDRAM, and installed it in conjunction with my Non ECC RDRAM. My system did not start and returned me with 3 post beeps (RAM failure).

The research I did into this was that PC800 ECC RDRAM was compatible with all Pentium 4's. But for some reason it is not with mine (Gateway Performance 1300). I did find out after the fact that RDRAM is supposed to be run with compatibility modules (clear RAM modules to fill the empty slots), this I never did as I didn't know I had to.

I now have the additional problem that when I removed the ECC RAM and replaced my old Non ECC RAM, they are not working at all now and return the three post beeps (RAM failure).

Could I have burned out anything in my mobo, or anywhere at all, during this exercise, that is causing my old RAM to fail?

RAM stats

Old RAM that did work together:

Samsung PC800 45 RDRAM 64mb/4 Non ECC (x2 - matched pairs thing)
Samsung PC800 40 RDRAM 128mb/4 Non ECC (x2 - matched pairs)

New RAM that has stopped all the other RAM from working:

Samsung PC800 45 RDRAM 256mb/16 ECC (x2 - matched pairs thing)

I can't get any other specs as my PC wont go past those three post beeps.

Please help, as I have a couple of major web design projects and a management course to complete. I was installing more RAM because my newly purchased Adobe Illustrator requires a minimum of 512mb of RAM to run.

[Ferrit]

I believe with Rdram it must be matched both in type and in size.
Also there should have been some dummy sticks beside the regular sticks which I think have to be in there as well

[NooNoo]

Remove the new ram. You can't mixed ecc and non ecc ram.

[slgrieb]

Holy Guacamole! You can buy a decent computer for less than the cost of 256 MB of Rambus memory! Ferrit is right, all RIMMs must be installed in pairs and all pairs must match. Can't mix ECC and non-ECC.

[nzgfxguru]

So could this have caused damage in my computer or just damaged the RAM that I put it in with?
The Non ECC ones that were working together,
Samsung PC800 45 RDRAM 64mb/4 Non ECC (x2 - matched pairs thing)
Samsung PC800 40 RDRAM 128mb/4 Non ECC (x2 - matched pairs)
no longer work together. Could the ECC one have damaged them or has the damage been done to my pc? They used to work but now the pc gives the 3 beeps.
Has this also done damage to the ECC RAM by putting it with the Non ECC?

[slgrieb]

Your computer and memory should both be fine. I hope you can return the memory for refund or exchange.

[NooNoo]

If the old sticks no longer work, you may have inadvertently zapped them with static electricity, or have fitted them incorrectly. This can damage the motherboard and the processor.

[slgrieb]

Static zaps happen, but it is really easy to fail to get your RAM modules seated correctly when the stress level gets a bit high. Just walk away for a bit and come back to it. BTW, don"t shuffle your feet on the carpet when you return. I still think your hardware is OK.

[Fraser]

Have you tried booting without any memory modules? Some of the POST tests will be done without any modules. You could install a POST code diagnostic card to see if it stops anywhere.