Adding a 3rd 5870... worth it?

[harmattan]

After I got my RMA back from one card, I've hooked my two PowerColor LCS 5870s running in Crossfire back up. I now have an extra Sapphire (fan cooled) 5870 lying around.

I'm wondering if it's worth the trouble on my board adding the third card for triple-Crossfire. I'm currently running on an Asus P6T (non-deluxe) which runs the PCIe lanes at 16x/16x/4x. I currently have a 9800 GT running in the third slot for Physx, but I've found it adds pretty much no benefit in games (actually slows down some games when Physx is engaged).

In addtion to the hassle of moving around my liquid cooled cards, I'd need to install a drive-bay PSU (which I already have) to power the third card, so man-hours are a factor as well as performance. Also worth mentioning I'm running 3x1 1900x1200 in Eyefinity. Also worth stating I'd be willing to spring for a new mobo that runs 16x/16x/16x if the performance gain would be worthwhile.

 

[guitarguy6]

I was under the impression that crossfire + eyefinity only worked in a few select games. Based on that I wouldn't bother with a 3rd 5870. If it's just sitting there collecting dust might as well try it out though.

 

[don_xvi]

I say do it so we can all ogle your results!

 

[GotNoRice]

I don't think you would be doing yourself any favors with the 3rd 5870 in the 4x slot.

Sell one of the 5870s and do Tri-fire with a 5970.

 

[harmattan]

I don't think you would be doing yourself any favors with the 3rd 5870 in the 4x slot.

Sell one of the 5870s and do Tri-fire with a 5970.

That's a good point, but I'd rather keep both my LCS cards and like the added OC headroom of three 5870.

If I got an Asus P6T6 Revolotion -- the only mobo I know of that does 16x/16x/16x -- would it be worth it?

Are there any other true 3x 16 lane mobos out there?

 

[Rizen]

The "true" 16x\16x\16x boards use the NF200 chipset. I would steer very, very clear of that chipset. The added latency typically offsets the bus speed gain to the point of it being a wash in performance anyways.

 

[kllrnohj]

I was under the impression that crossfire + eyefinity only worked in a few select games. Based on that I wouldn't bother with a 3rd 5870. If it's just sitting there collecting dust might as well try it out though.

I think that was only the 9.12 Hotfix. According to the recent [H] preview of Cat 10.2:
http://hardocp.com/article/2010/02/17/amds_ati_catalyst_102_103_preview/

ATI CrossFireX is now fully supported with ATI Eyefinity. This means now that all CrossFireX configurations will accelerate ATI Eyefinity display groups in your games. This means you can use the Radeon HD 5970, Radeon HD 5870 CrossFireX, Radeon HD 5850 CrossFireX, and on and on and on with ATI Eyefinity.

I'm not running CF so I can't vouch for that, but it is supposed to work now.

 

[trudude]

I thought about doing a third card, but honestly performance for me is great. I would just say stick with what you have.

 

[harmattan]

I think that was only the 9.12 Hotfix. According to the recent [H] preview of Cat 10.2:
http://hardocp.com/article/2010/02/17/amds_ati_catalyst_102_103_preview/


I'm not running CF so I can't vouch for that, but it is supposed to work now.

I can vouch for that. CF scales much better since the hotfix and 10.2, especially in Eyefinity.

Anyone have triple Crossfire or SLI experience on this? http://www.newegg.com/product/product.aspx?Item=N82E16813188046 It looks to operate 16x/16x/8x...