can i cross fire 2 differnt 4870?

[markiejt]

i.e differnt makes?

 

[4T5]

Yes.
They will default to the slowest speed though.

 

[markiejt]

so as long as they are just normal 4870 they will be ok, as at moment got 1 saphhire but xfx is cheaper now

 

[4T5]

Yes.

 

[Ben M]

Yes.
They will default to the slowest speed though.

Yes you can run them both, and they will run at independent speeds.

With nvidia's sli they run at the lower speed, with crossfire they run independently So you can overclock them independently.

 

[AMG]

yes you can I have two very different HD4870 some how one looks like its a toxic but its not lol

 

[LoadsaMoney]

Yes you can as said above, just don't pair a 1gb with a 512mb, as it will only give you the 512mb, as it will only give you the Ram from the card that has the lowest amount when different memory configs are used.

Also according to this review, the faster card downclocks.

http://www.hardwarecanucks.com/forum/hardware-canucks-reviews/9159-ati-hd4870-hd4850-crossfire-performance-review-16.html

 

[Ben M]

Yes you can as said above, just don't pair a 1gb with a 512mb, as it will only give you the 512mb, as it will only give you the Ram from the card that has the lowest amount when different memory configs are used.

Also according to this review, the faster card downclocks.

http://www.hardwarecanucks.com/forum/hardware-canucks-reviews/9159-ati-hd4870-hd4850-crossfire-performance-review-16.html

Where does it say there that two 4870s have to run at the same speed?
It doesn't, they run at independent clock speeds.

as per here:
http://forums.overclockers.co.uk/showpost.php?p=13876668&postcount=7

and here:

http://forums.overclockers.co.uk/showpost.php?p=13876735&postcount=9

 

[LoadsaMoney]

I think they do run at their own independant speeds, but that doesn't make a difference, as the faster card will always have to wait for the slower card, so thats probably why they say you see no increase in performance, as the clock speeds mean diddly squat, the faster card always has to keep stopping and waiting for the slower one, so in effect they may as well be running the same speeds.

 

[Final8y]

I think they do run at their own independant speeds, but that doesn't make a difference, as the faster card will always have to wait for the slower card, so thats probably why they say you see no increase in performance, as the clock speeds mean diddly squat, the faster card always has to keep stopping and waiting for the slower one, so in effect they may as well be running the same speeds.

That's a good point.