crossfire 4850 512 vs 4850 1gig

[hojl]

Do I loose anything from having 4850 512 vs 4850 1gig?

I actually have 1 4850 512 meg and 4850 1gig. I am thinking of crossfiring these. I read that these should work together but I loose 512meg on the 1gig card. Would it be worth the hassle of selling the 4850 512meg and getting a 4850 1gig?

I generally play a range of games I generally purchase from steam including
blackops
fallout 3
bc2
red alert 3

 

[RavenSEAL]

Blah

 

[RavenSEAL]

Actually, that number is probably wrong.

 

[toyota]

Actually, that number is probably wrong.

use the edit button. having a 1gb and 512mb card in crossfire will mean he only has 512mb of vram.

 

[RavenSEAL]

use the edit button. having a 1gb and 512mb card in crossfire will mean he only has 512mb of vram.

Sheez, don't gotta call me out...

 

[Maximilian]

use the edit button. having a 1gb and 512mb card in crossfire will mean he only has 512mb of vram.

Wouldnt he have 1GB in total with the two cards both having 512mb accessible to them? Or does he completely lose the 1GB from that other card?

 

[Termie]

This review will give you some idea of how two 4850 512MB cards will perform: http://www.hardocp.com/article/2009/03/08/sapphire_radeon_hd_4850_x2_1gb/1. In some cases, the performance is higher than the 4870, but in some cases it is lower, which is due to the memory limitation. In newer games like BC2, you'll need the extra memory. I'd look around for a 1GB card if you're really interested in greater performance.

 

[toyota]

Sheez, don't gotta call me out...

well you hardly ever use the quote or edit buttons so it causes clutter and confusion sometimes. no need to get upset. :wub: :biggrin:

 

[Qbah]

Wouldnt he have 1GB in total with the two cards both having 512mb accessible to them? Or does he completely lose the 1GB from that other card?

He won't loose anything. The cards will work in AFR mode (meaning they do full frames each, in sequence 12121212 etc). Hence only 512MB will be available - either the full 512MB on one card or half of the 1GB on the other (depending on the rendered frame). In short

 

[toyota]

Wouldnt he have 1GB in total with the two cards both having 512mb accessible to them? Or does he completely lose the 1GB from that other card?

not trying to be rude but I thought you would know thats not how it works after 6 years of regular posting on here. two cards in sli/crossfire only mirror the ram. if one card only has 512mb while the other has 1gb then only 512mb gets mirrored though. I am sure somebody can explain it much better than that though.

 

[hojl]

Hey thanks. I am gonna read that Hardocp article. However, Termie says above that some cases I may not even get 4870 performance? That seems a bit underwhelming.

 

[Qbah]

Hey thanks. I am gonna read that Hardocp article. However, Termie says above that some cases I may not even get 4870 performance? That seems a bit underwhelming.

It will happen in games with no or poor crossfire scaling. Also if you're playing in windowed mode (crossfire doesn't support it afaik).

Before you commit to it, check out some results for games you're playing or are planning to play.

 

[Maximilian]

not trying to be rude but I thought you would know thats not how it works after 6 years of regular posting on here. two cards in sli/crossfire only mirror the ram. if one card only has 512mb while the other has 1gb then only 512mb gets mirrored though. I am sure somebody can explain it much better than that though.

Not trying to be rude either but I thought you would know after 10 years and 4k posts that post count and time spent here is no indicator of technical knowledge, see OT forum for details.

Besides, ive always had single card setups, new next gen card >= xfire last gens typically so ive never bothered with it.

 

[hojl]

I just finished reviewing that Hardocp article. I see that basically performance is limited by the 512 ram. I should have done more research before I bought a crossfire mobo.

Oh well live and learn.

 

[BD231]

I just finished reviewing that Hardocp article. I see that basically performance is limited by the 512 ram. I should have done more research before I bought a crossfire mobo.

Oh well live and learn.

There are few cards on the market that offer 1600 shaders buddy, you highly underestimate the combo.

 

[hojl]

Well the review makes it seem like the 2 4850s will perform similar to 4870. It seems I am better off selling the two 4850 and getting something newer or just a 4890....

 

[Modular]

This review will give you some idea of how two 4850 512MB cards will perform: http://www.hardocp.com/article/2009/03/08/sapphire_radeon_hd_4850_x2_1gb/1. In some cases, the performance is higher than the 4870, but in some cases it is lower, which is due to the memory limitation. In newer games like BC2, you'll need the extra memory. I'd look around for a 1GB card if you're really interested in greater performance.

Not exactly true, as that's a single card, dual GPU solution. Here's a better review. I can't say how accurate these numbers are today, especially with driver improvements and so on, but this review makes 2 4850's at 512MB each seem pretty compelling:

http://www.guru3d.com/article/radeon-hd-4850-and--4870-crossfirex-performance/

Edit: My understanding from others on this forum is that 2x 4850's are comparable to a 5850 in almost everything, and beat it out in some games. Take that for conjecture, as I can't comment for sure myself.

 

[hojl]

You know I was hoping that it was near 5850 or 5830 or so...
thanks for the new article.

 

[Qbah]

You know I was hoping that it was near 5850 or 5830 or so...
thanks for the new article.

When not VRAM limited (and in a game that scales properly - luckily most do), two HD4850s are a bit faster than a GTX285. So they are just under a stock HD5850 performance-wise. But tbh I wouldn't bother with that - you can get a HD5850 for under $200 with rebates and a good promotion, mostly because they are phased out (hell, there was a GTX470 for under $200 recently too!). They are a lot better than adding a second HD4850 - no scaling issues, better feature set (DX11), lower noise (at least the HD5850, though custom cooled GTX470 are also decent). Try to find those cards and sell the HD4850 for a small monetary recoup.

 

[Modular]

When not VRAM limited (and in a game that scales properly - luckily most do), two HD4850s are a bit faster than a GTX285. So they are just under a stock HD5850 performance-wise. But tbh I wouldn't bother with that - you can get a HD5850 for under $200 with rebates and a good promotion, mostly because they are phased out (hell, there was a GTX470 for under $200 recently too!). They are a lot better than adding a second HD4850 - no scaling issues, better feature set (DX11), lower noise (at least the HD5850, though custom cooled GTX470 are also decent). Try to find those cards and sell the HD4850 for a small monetary recoup.

Typically I would agree. However I'm guessing that the OP got in on this deal:

http://forums.anandtech.com/showthread.php?t=2130356

If that's the case, then you can't beat the performance for the price!

Edit: Just browsed the thread...I guess I was wrong as he posted right in there that he didn't get in on it. I guess it ends up depending on how much he spent on the extra 4850...