More Crossfire Questions

[mother242]

sorry about closing the last question, i just wanted to know whether using a 5850 and 5870 in crossfire would produce LESS performance that two 5850 in cf.

thx

 

[wolfram23]

Shouldn't be less, but it would be very close to two 5850s. Maybe slightly higher. Either the 5850 will raise it's clocks to 5870 levels or the 5870 might lower it's clocks. If the 5850 raises it's clocks there could be some issues.

 

[wa1]

Less? No...
But you will waste HD5870 as it will reduce it speed to match HD5850 speed.

1. HD5850 (normal speed) + HD5870 (reduce speed).
2. HD5850 (normal) + HD5850 (normal).
3. HD5850 (OC) + HD5870 (normal)

Your choice...

 

[mother242]

Shouldn't be less, but it would be very close to two 5850s. Maybe slightly higher. Either the 5850 will raise it's clocks to 5870 levels or the 5870 might lower it's clocks. If the 5850 raises it's clocks there could be some issues.

Issues???

 

[mother242]

Less? No...
But you will waste HD5870 as it will reduce it speed to match HD5850 speed.

1. HD5850 (normal speed) + HD5870 (reduce speed).
2. HD5850 (normal) + HD5850 (normal).
3. HD5850 (OC) + HD5870 (normal)

Your choice...

yeah sorry thats what i thought but they way you wrote it before suggested that it may decrease performance, and i was like no way man

anyway ill probably get the 5870 and overclock the 5850 in sometime, will wait until the 6xxx series comes out until i get the 5870 tho. might see a bit of a price drop

 

[wolfram23]

If the 5850 can't handle 5870 clocks, it'll cause issues. Core clock isn't the problem usually it's memory because you can't add memory voltage, plus memory usually doesn't have the best cooling.

 

[mother242]

If the 5850 can't handle 5870 clocks, it'll cause issues. Core clock isn't the problem usually it's memory because you can't add memory voltage, plus memory usually doesn't have the best cooling.

wont i be able to simply clock the memory down via the ATI overdrive software

 

[wolfram23]

Potentially.

Why not go with two 5850s or two 5870s tho?

 

[wa1]

You can't just push your card to match HD5870 speed, some of HD5850 can do that and some of them can't...
What is your HD5850 exactly?

 

[mother242]

You can't just push your card to match HD5870 speed, some of HD5850 can do that and some of them can't...
What is your HD5850 exactly?

HIS ATI Radeon HD5850 1GB GDDR5, not a special eddition with aftermarket stuff added on but just the normal modle

 

[mother242]

Potentially.

Why not go with two 5850s or two 5870s tho?

already have 5850 i am thinking of upgrading to a cf system, dont want to just chuck out the 5850, but i was thinking that the 5850 would get a larger performance boost from being crossfired with a 5870 than just with another 5850

 

[wolfram23]

In that case, go read my thread comparing single and CF 5850s

http://www.tomshardware.com/forum/289809-33-single-5850-furmark-crysis-stalker-dirt

I think you should be very satisfied with CF 5850s.

 

[wa1]

I think your HIS card can't OC'ed by FAR (match HD5870 speed), so you will better add another HD5850.
Believe us, Dual HD5850 will CRUSH anything and i'm sure you will last for a loooong time before upgrading to any higher card.

 

[mother242]

thanks guys ill go and get a 5850