ECC vs. Non-ECC Memory -- Can they be mixed (in separate slots)?

[Steven O.]

I am upgrading a computer that uses RDRAM (Rambus) memory. One pair
of slots on the motherboard is filled, and I have found matching RDRAM
on E-bay. The only thing is, I'm not sure whether what it's the
computer now is Error-Corrrecting, and also not sure if the chips I
want to buy are error correcting.

Assuming everything else matches (same bus speed and refresh rate), is
it okay to have one pair of memory chips that are error-correcting,
and another pair that are not? Would the motherboard care either way?

(My best guess is that the current configuration is probably not
error-correcting, so then the question would be, is it okay to add a
second pair of memory chips that are error correcting?)

Thanks in advance for all replies.

Steve O.


"Spying On The College Of Your Choice" -- How to pick the college that is the Best Match for a high school student's needs.
www.SpyingOnTheCollegeOfYourChoice.com

 

[Tony Hill]

I am upgrading a computer that uses RDRAM (Rambus) memory. One pair
of slots on the motherboard is filled, and I have found matching RDRAM
on E-bay. The only thing is, I'm not sure whether what it's the
computer now is Error-Corrrecting, and also not sure if the chips I
want to buy are error correcting.

Generally speaking, unless they are sold as ECC memory, they probably
aren't.

Assuming everything else matches (same bus speed and refresh rate), is
it okay to have one pair of memory chips that are error-correcting,
and another pair that are not? Would the motherboard care either way?

Unfortunately the answer here is "maybe".

It could go either way. Some boards will work with mixed ECC and
non-ECC memory (the board would simply treat all memory as if it were
non-ECC stuff), some will not.

On most boards I would guess that you would have about a 50% chance of
it working, maybe a bit better, but RDRAM is a whole different beast.
I don't have enough experience with RDRAM to say for sure if you're
chances are better or worse than with more standard memory types.



Hmm..

www.SpyingOnTheCollegeOfYourChoice.com

Am I the only one that thinks this sounds like a porn site?! :>

 

[keith]

Generally speaking, unless they are sold as ECC memory, they probably
aren't.

Was there non-ECC RDRAM sold? Really?

 

[daytripper]

Was there non-ECC RDRAM sold? Really?

Well, "For Sale", at least.

http://www.samsung.com/Products/Semiconductor/common/product_list.aspx?family_cd=DRM040201

/daytripper (I dunno if they actually sold any before the wheels fell off ;-)

 

[keith]

Well, "For Sale", at least.

http://www.samsung.com/Products/Semiconductor/common/product_list.aspx?family_cd=DRM040201

/daytripper (I dunno if they actually sold any before the wheels fell off ;-)

I thought that's why there weren't any non-ECC RIMMs sold. ...the wheels
fell off before it even went to market. ;-)

 

[Tony Hill]

Was there non-ECC RDRAM sold? Really?

Yup. In fact, it was rather common. I don't know of any exact
figures, but I would throw out a guess that at least half of all the
RDRAM systems I came across uses non-ECC RDRAM.

If you can save a buck...

 

[keith]

Yup. In fact, it was rather common. I don't know of any exact
figures, but I would throw out a guess that at least half of all the
RDRAM systems I came across uses non-ECC RDRAM.

Amazing, since it didn't work worth crap.

If you can save a buck...

....why would you even venture into RDRAM? Oh, I forgot, because I$ (and
JC) said is was wunnerful.