4850x2, 4890 tri-fire

[spacecowboy9891]

I bought a 4850x2 this christmas and I was wondering what type of performance gains I might see my slapping a new 4890 in there with it?

 

[happy medium]

I think it would be the same as adding another 4850. I believe the 4890 will scale back to a 4850. Someone correct me if i'm wrong.

 

[SSChevy2001]

Tri-fire with a 4890 would be a waste of money, as it just going to downclock the 4890 to run 4850x2 clock speeds anyway.

Quad-fire setup doesn't scale that well. So the only other option is a tri-fire setup, but only if you have the 2GB 4850x2. Even if you go a 4850x3 setup though your going to be CPU limited in some titles with that e6400 @ 3.0Ghz. Overall I would just say stay with what you got for now until you replace the CPU.

 

[Sylvanas]

They don't downclock these days, as of Catalyst 8.1 different GPU's can run at different core and memory clockspeeds. Anyone with a Crossfire setup can try this in the CCC Overdrive and check the speed in GPU-Z. A 4890 will perform at it's stock speed and will of course give gains in games that scale well and in others not so much.

 

[SSChevy2001]

Originally posted by: Sylvanas
They don't downclock these days, as of Catalyst 8.1 different GPU's can run at different core and memory clockspeeds. Anyone with a Crossfire setup can try this in the CCC Overdrive and check the speed in GPU-Z. A 4890 will perform at it's stock speed and will of course give gains in games that scale well and in others not so much.

This review was taken with 8.7 drivers and according to their review the 4870 did downclock. Their scores show no real improvement over a regular CF setup, and the idle power was higher. Either way this review clearly shows hybrid CF is a waste of money.

HD4870 + HD4850 Crossfire

The problem with this type of configuration is the fact that the faster of the two cards will always downclock to keep pace with the slower card. This means that the core speed of 750Mhz and blistering memory speed of 3.6Ghz on a HD4870 means absolutely squat when paired up with a HD4850 running at 625Mhz / 1.986Ghz.

http://www.hardwarecanucks.com...ormance-review-16.html

 

[Sylvanas]

Originally posted by: SSChevy2001

Originally posted by: Sylvanas
They don't downclock these days, as of Catalyst 8.1 different GPU's can run at different core and memory clockspeeds. Anyone with a Crossfire setup can try this in the CCC Overdrive and check the speed in GPU-Z. A 4890 will perform at it's stock speed and will of course give gains in games that scale well and in others not so much.

This review was taken with 8.7 drivers and according to their review the 4870 did downclock. Their scores show no real improvement over a regular CF setup, and the idle power was higher. Either way this review clearly shows hybrid CF is a waste of money.

HD4870 + HD4850 Crossfire

The problem with this type of configuration is the fact that the faster of the two cards will always downclock to keep pace with the slower card. This means that the core speed of 750Mhz and blistering memory speed of 3.6Ghz on a HD4870 means absolutely squat when paired up with a HD4850 running at 625Mhz / 1.986Ghz.

http://www.hardwarecanucks.com...ormance-review-16.html

Odd, since both the 3850/70 and 2900Pro/XT changed clockspeeds to their respective range (apoppin had a thread on this a while back) and so does my 4870X2, I can post GPU-Z screenshots if you'd like. Perhaps you have to physically open up Overdrive and set the Superior GPU to its stock (higher) speed as it may not do it automatically. This would mean with a 4870/50 setup you;d open Overdrive, select the 4870 and simply bump up the core/mem to what it's stock speeds are.

Of course there is not going to be much difference between a 4850 x 2 setup and a 4870+4850 setup- what the OP is asking for is a 4850X2 + 4890, 3 GPUs vs 2.

 

[SSChevy2001]

Originally posted by: Sylvanas
Of course there is not going to be much difference between a 4850 x 2 setup and a 4870+4850 setup- what the OP is asking for is a 4850X2 + 4890, 3 GPUs vs 2.

I think your missing the point, which is mixing a 4850x2 + 4890 in CF is equal to a 4850x3. Why spend the extra money on a 4890 when you can buy a 4850 cheaper?

 

[Sylvanas]

Originally posted by: SSChevy2001

Originally posted by: Sylvanas
Of course there is not going to be much difference between a 4850 x 2 setup and a 4870+4850 setup- what the OP is asking for is a 4850X2 + 4890, 3 GPUs vs 2.

I think your missing the point, which is mixing a 4850x2 + 4890 in CF is equal to a 4850x3. Why spend the extra money on a 4890 when you can buy a 4850 cheaper?

No, as I said, the 4890 is not relegated to 4850 speeds as you can set individual clocks in CCC. So in effect you'd have a 4850X2 + a 4890 running at their assigned stock speeds (the 4890 running at the much higher 850mhz core)- this would not be equal to 4850x3 as the 4890 would be running at full pace giving a slight advantage over that of 4850x3. Would that slight advantage be worthwhile over a 4850x3 system, probably not, maybe a few fps here and there.

 

[SickBeast]

You get diminishing returns with each GPU added.

If I were you, OP, I would sell the 4850x2 and get another 4890 if you really want uber performance.

 

[spacecowboy9891]

I think I will go with the third 4850 soon then. I think the 4850x2 is going to be more than enough for awhile though. I was just worried about rendering over two monitors.

 

[Tempered81]

Originally posted by: SickBeast
You get diminishing returns with each GPU added.

If I were you, OP, I would sell the 4850x2 and get another 4890 if you really want uber performance.

+1 sell what you have and get 4890 Xfire. Then overclock them.