4850 x2 2gb vs 4890

[imported_Ivan244]

So it looks like in the separate benchmarks 4850 x2 is a little faster then 4890. In Farcry 2 it appears that the 4850 x2 is way ahead of the 4890.

However, not sure how well the 4850 x2 OCs and it looks like most 4890s should be able to reach 900mhz OC levels.

Right now current price for 4850 x2 2gb is 265 after rebate and 4890 is 230 after rebate. My question is if you had the choice, would the $35 extra be worth it to get 4850 x2 2gb? Or would you go with lower cost 4870?

Looking to move 4870 to second comp (which as two 3870 xfire) and xfire with 3870. Whichever I get 4870/4890/4850 x2 I'll xfire with second 3870 in main comp. Playing L4d, FC2, and Crysis Warhead currently.

Main comp has FW900 monitor (Vista 64) and normally game at 1920x1200. Second comp has Lcd 1680x1050 (Xp 32)

Thanks

Edit: I posted my two 3870 today on Craigslist and immediately had someone come over and pick them up. Figured everyone here was better informed than me on Xfire anyways So now need new vid card for second comp (Fallout 3/HGL). What I will probably wind up doing is picking up 4890 and moving the 4870 to the second comp. Thanks to everyone for chiming in with info.

 

[Udgnim]

if same or similar performance, always go for the single GPU over the multi-GPU setup

 

[error8]

When it scales, 4850X2 is faster then any single GPU card on the market, regardless of the oc or anything else. When it doesn't, you remain at 4850 performance level, but I think that most of the time, the card will scale well. If you're going to buy the X2, make sure it's the 2 gb version (1 gb per gpu) since you'll be needing large frame buffer for 1920X1200.

And I don't know if it's a great idea to xfire a 4XXX card with a 3870. I don't know if it works and if it's supported by drivers.

 

[imported_Ivan244]

Originally posted by: error8
When it scales, 4850X2 is faster then any single GPU card on the market, regardless of the oc or anything else. When it doesn't, you remain at 4850 performance level, but I think that most of the time, the card will scale well. If you're going to buy the X2, make sure it's the 2 gb version (1 gb per gpu) since you'll be needing large frame buffer for 1920X1200.

And I don't know if it's a great idea to xfire a 4XXX card with a 3870. I don't know if it works and if it's supported by drivers.

I may be wrong but I thought that was the main difference between Crossfire and SLI. With SLI you had to have matching cards but with Xfire you could have different cards. The 3870 would be for extra help not a 50% load match.

 

[AzN]

Try more like 1ghz overclocking levels. Seems 4890 have good overclocking potential compared to 4870.

http://firingsquad.com/hardwar...rce_gtx_275/page13.asp

 

[error8]

Originally posted by: Ivan244

Originally posted by: error8
When it scales, 4850X2 is faster then any single GPU card on the market, regardless of the oc or anything else. When it doesn't, you remain at 4850 performance level, but I think that most of the time, the card will scale well. If you're going to buy the X2, make sure it's the 2 gb version (1 gb per gpu) since you'll be needing large frame buffer for 1920X1200.

And I don't know if it's a great idea to xfire a 4XXX card with a 3870. I don't know if it works and if it's supported by drivers.

I may be wrong but I thought that was the main difference between Crossfire and SLI. With SLI you had to have matching cards but with Xfire you could have different cards. The 3870 would be for extra help not a 50% load match.

Yes, I'm aware of that, but I've heard that these types of xfire combinations, between different generation cards, are not that efficient.

 

[T2k]

Originally posted by: error8
When it scales, 4850X2 is faster then any single GPU card on the market, regardless of the oc or anything else. When it doesn't, you remain at 4850 performance level, but I think that most of the time, the card will scale well. If you're going to buy the X2, make sure it's the 2 gb version (1 gb per gpu) since you'll be needing large frame buffer for 1920X1200.

Well said. It runs everything crazy fast I throw at it in 1920...

 

[thilanliyan]

Wouldn't XFiring with 3870 bring the other card(s) down to 3870 level performance? I wouldn't do it...you might end up slower in some situations.

 

[imported_Ivan244]

Originally posted by: thilan29
Wouldn't XFiring with 3870 bring the other card(s) down to 3870 level performance? I wouldn't do it...you might end up slower in some situations.

I'll need to go back and do some research. From what I understood the Xfire software was advanced enough to use the slower card to perform menial tasks freeing up the faster card. Not huge performance increases but depending on the second card would provide some boost. It's been awhile so I may be making up stuff

 

[error8]

You should try crossfiring them and see what happens. It's not like they're going to die or something.

 

[cusideabelincoln]

Eh, your research is a little wrong. If you Xfire a 3870 with an HD4870, the HD4870 will basically run at HD3870 speeds and you'll effectively have Xfire 3870s, which is already what you have. You would be losing performance. And I'm not even sure you can Xfire cards of different generations. I don't think you can actually put a 3800 series card with a 4800 series card.

What you should do is buy either an HD4870 or HD4890 and Xfire it with your current HD4870. That will give you the best performance in your main computer. Leave your secondary computer alone.

edit:
If you went with the HD4850 X2 and Xfired it with your current HD4870, you'll effectively have three HD4850s running in Tri-fire. Whether or not three HD4850s will give you better performance than two HD4870s/4890s depends on how well Xfire scales with a certain game. Some games scale pretty well, while I believe most scale like crap. Look at AT's multi-GPU articles to see for yourself... I'll probably edit them in shortly...

http://www.anandtech.com/video/showdoc.aspx?i=3518&p=6
Crysis Warhead, 19x12:
HD4850 Trifire: 42.7
HD4870 (512mb) Xfire: 38.9

Looks like Xfire scales ok in this game, although if you have the 1GB version of the HD4870 then you'd probably get better results than these.

FC2, 19x12:
HD4850 Trifire: 23.7
HD4870 (512mb) Xfire: 53.8

Looks like there's some kind of weird negative scaling when moving from two to three HD4850s. This is probably an anomaly in the benchmarks, since three HD4870s do just fine at 56.5 fps. Whatever the case, dual HD4870s/90s would again be the better option for you.

Left 4 Dead, 19x12:
HD4850 Trifire: 110
HD4870 (512mb) Xfire: 105

Looks like three-way holds a small advantage. However, I believe if you have the 1GB version of the HD4870 you would see better results here as well.

In summary, dual HD4870s would be a much more elegant solution, especially if you have the 1GB version. In the three games you mentioned, dual HD4870s would basically give you the same performance as a three HD4850s, and of course would be much better than having two, three, or even four HD3870s.

 

[thilanliyan]

Originally posted by: cusideabelincoln
And I'm not even sure you can Xfire cards of different generations. I don't think you can actually put a 3800 series card with a 4800 series card.

I think you can but like you mentioned it would run at the slower speed of the 2 cards.

 

[imported_Ivan244]

Error8 had a great idea. Why not try it out? Since I have two 3870 in second comp I'll break the xfire and add one and see what happens via Fraps.

 

[cusideabelincoln]

I'll bet your minimum framerates will take a huge dump.

 

[jordanclock]

You cannot Crossfire HD4000 series cards with HD3000. Despite being very similar, they simply won't work. If you were so inclined, you might be able to modify the driver to support this combination, but I have not heard of any success in doing this and I'm sure if it were that easy, AMD would give you the option.

 

[cbn]

It looks like new egg has already added rebates to the HD4890 now that GTX 275 benchmarks are out.

$229.95 is a better price for the HD4890. It is just too bad they had to do this with rebates.

 

[Sylvanas]

Originally posted by: jordanclock
You cannot Crossfire HD4000 series cards with HD3000. Despite being very similar, they simply won't work. If you were so inclined, you might be able to modify the driver to support this combination, but I have not heard of any success in doing this and I'm sure if it were that easy, AMD would give you the option.

This. Cannot Xfire 3000 with 4000 series- been discussed before. If it were me I'd go the single 4890 simply because of the overcloackability and adjustable voltage. Crossfire is fine for scaling in recent games I have experienced no problems.

 

[ronss]

quess i would go for the 4890...since some games will not utilize the 4850,s x2 cores ........from what i have read...the 4850 x2 overall is a tad faster than a 4890...but not allways.. generally it is.. you will get many different opinions on which to buy,

 

[yh125d]

Ditto what Azn said. Almost all 4890s can do 950+ core. Mine autotunes to 990 core 1125 mem using stock voltage, so I could even go a bit from there. I'd go for the 4890, since it can be had easily at $175 or less, is shorter, cooler, lower power, and no hassle of multi-GPU when it doesnt scale, even if thats rarely

 

[vj8usa]

http://ati.amd.com/technology/crossfire/charts.html

Shows which GPUs can be crossfired together. You can't crossfire across different generations.

edit: oops, just noticed the date of the OP. Not sure why ronss bumped this thread.