4890 + 4850 or 4870

I want to add another card to crossfire with my 4890.

Since my 4890 was a bit pricey I was wondering if I could add a lower end card without disadvantages.

Will the 4890 scale down to the level of a 4870 or 4850 ?

If the 4890 doesn't scale down what kind of performance should I expect?

Thx!

I agree with AMG. Generally getting two different models results in the faster one slowing down for the slower one, in your case the 4890 becoming a 2nd 4850. There are cases where the slower one speeds up, but I wouldn't risk it. I would just keep the 4890, until you can get a second one.

I don't think it will, as the HD4870 can't clock the same speeds as the HD4890 ethoir memoery or core, the shader clock is the same through still 800

like wise for putting a HD4850 your only going to downgrade your HD4870 which as GDDR5 nad its proven to make a differance

crossfire will always work off the slowest card in the configeration, say if AMD did physics X so you had crossfire + a little HD3870 for physics say that wouldn't make a differneces as its not part of crossfire, add it too crossfire, and it will slow your two faster better cards down.