Switched from 4870 CF to single 5870

I thought i'd share this with you guys. Recently i bought a pair of 5870 to install them as crossfire in my M17x R2. long story short: it didn't work out! my system would not boot

After contact with the seller, which was so nice to test my cards themself, the conclusion was: my R2 motherboard clearly rejected the crossfire solution of two 5870's (while the 4870's work just fine!) so i got a refund for one of the cards (thank you ukportableparts ) and installed one card.

The differences? first off, i hardly notice performance differences between the cf 4870 and the single 5870 in most of the games. furthermore the machine is less noisy and certainly generates less heat, third; the machine draws less power noticeable with tooling like Hwmonitor and the fact that the adaptor will get moderately warm instead of real hot!

My conclusion; a crossfire solution is real nice when it works like a charm and performs noticable better then a single card. if not i'd settle with a pretty good single card.

 

Glad you are happy with the overall performance. it is strange that your R2 rejected the second card. Maybe it wasnt registered as a slave card. Someone here will be able to inform you about other options on how to find a slave 5870 (with cable, hopefully) or how to BIOS flash said card to a daughter/slave card.

Good Luck!

 

It wouldn't boot? What the heck? The 5870 crossfire is oficially supported by DELL in the R2, and it works flawlessly in my R1 (where dell doesen't support it.)

I'm almost sure that you have done something wrong when installing those cards.

- Did you remember the Crossfire cable?
- Did you put them properly into the PCI-slots?
- Did you try to assemble your system multiple times? You might have forgotten / assembled something badly.

- Scott.

 

If you were going to go with a single card inside of an m17x-R2 I would have gone with the 6990 not a 5870.

 

^
What he said. A single 6990 is about as good as 5870M in crossfire with less power draw.

 

Thanks for all your reactions, about problem solving; i tested the cards with CF cable (i have 2 of them, swapped then, no go) i also swapped the cards heatsinks and tried them both on the first channel. this all worked, confirming me both cards worked. i also installed the Dell BIOS for them. the point is the system just went blank as soon as i put 2 5870's in it, swapping back to the 4870 CF, that all worked...

With the two 5870's (and cf-cable installed) the machine started up like allways (what i mean by this is that the machine would start with a lighting alien head power putton and the fans would spin up that same as when they would with the 4870 cf installation) there would just not appear anything on screen...

6990's are hard to come by in my country or i would have to ship them from the states...

 

The proper ones for the R2 don't even come from the states they come from Canada but oh well