2 x 2900Pros in Crosssfire OR 1 x 8800GTX - what do you think?

Blue frog

Distinguished
Nov 6, 2007
28
0
18,530
0
Thinking of upgrading from a single X1950XT. Have a Crossfire mobo.

Heard that the 2900 Pro with mild OCing is as good as the 2900 XT.

Have narrowed it down to sticking with ATI and moving up to crossfire or changing to the darkside with nVidia, but can't decide which - - any thoughts out there????? :ouch:
 

atomicWAR

Judicious
Herald
when in doubt go with one card that is better than two lessers in sli/crossfire. though if ur gaming in resolutions equal or greater than 1600x 1200 or 1080p (if ur using an hd tv) do get some benefit from running both cards with all the goodies on, though ulitmatey it is not the most cost effective or dependible way to increase frame rates per dollar. that said though crossfire setups are much cheaper than the sli i am running (2 8800 gtx's). its ur call really. heard the 9800 hundreds are hitting the market in febuary...so if ur not desprate i might try and hold out. certainly one of those will out perform anything in crossifre, sli or single gpu configuration by a factor of 2 (if nvidia keeps with past trends). i ran two 7800 gtx's in sli and they got spanked by one 8800gtx...so i only ran one 8800 gtx tell recent when the games started taxing my cpu/ gpu. that said i can't wait for next gen vards and pci-2.0 to be standard on all new mobo's....i'll be itching for an upgrade quite awhile as i have been holding off so new techonolgies can penatrate the market. and make it worth m money.
 

spoonboy

Distinguished
Oct 31, 2007
1,053
0
19,280
0
Its a tricky question really, depending on what your psu is like, how much risk your willing to take and how tech-savvy you are or willing to be.

First off is the old multi card versus single card performance issue. As it stands not all games support crossfire well, but then again crossfire has improved a great deal and it is approaching being a practical solution, although its not quite there yet. Its a driver issue above all, and so you have to wait on improved catalyst drivers in the coming months (however as far as I know there are no crossfire benchmarks with the latest catalyst 7.11, so as to whether they are much better in this respect remains to be seen). Thats the risk part. Things look bright however in this respect as crossfire seems to be amd's strategy to reclaiming the performance crown from nvidia, what with quad crossfire on the horizon and the new radeon 3900: a duel gpu card, apparently ready hardware wise but waiting for the best possible drivers to make it work well in as many games as possible, which amd have given themselves until february to finalize. Thats a bit of a wait, but then again its a good idea to wait until you have 'killer' drivers before releasing the product that uses them, rather than releasing a product and ironing out driver issue as you go along (see: 2900xt ! )

Assuming all goes well or at least quite well, then you have to consider your psu. Both the 2900 series and the 8800gtx are power hungry, and you will need a quality psu over 500 watts for a single gtx and something around 650 watts for crossfired 2900 xt's. Whether a psu is 'up to the job' or not is not always a question of wattage, as amperage on the 12volt rails needs to be sufficient to. This usually means that a branded psu at a given wattage will be more capable than a cheaper generic psu at the same value, as the cheaper ones often cannot sustain performance at higher loads.

Lastly, I mentioned crossfire'd 2900 xts and not pros because it would appear that the pro is for all intents and purposes identical to the xt except with a different bios that sets the default clocks to 600mhz core, rather than the 740mhz of the xt. Im not entirely sure of this, but I believe the pro bios restricts the overclocking potential of the card. Every pro should be able to reach xt core and memory speeds easily on the standard cooler (the same cooler as the xt) and standard voltages but has trouble reaching the same max overclock as the xt. However if you flash the pro cards with an xt bios, it will use default xt clock speeds and be able to overclock to higher maximum speeds. Flashing the bios is the tech savvy part! it can go wrong!

note: despite what is said, 8 pin connectors for the 2900s are not needed to overclock them, but having them or using a 6pin to 8pin adaptor will make it easier.

Therefore crossfired xts or pros at xt speeds should run rings around a single gtx in games that support crossfire well. That list is not the largest right now, but should improve in the coming months. This crossfire will be power hungry, but perhaps your not overly concerned with that. A word of warning all the same! The final thing to consider is that both cards are old technology now, and so cheaper better replacements are either on the horizon in the gtx's case, or already here in the 2900's case. If you can pick up 2 2900pros cheaply or even second hand from, say, ebay, then with a bit of work and some luck on the driver side in the coming months you can put together a very powerful graphics setup, which should be able to max out any game except crysis (although crysis patches and newer drivers will supposedly improve crossfire and sli performance a great deal).

Note: although the 2900 series has now been replaced by the 3800s, in my personal opinion, so take it or leave it!, I dont believe that driver development for the older cards will come to a standstill now. Not only would that be very premature as the 3800s havent been out very long, and still are not available in huge volumes, but also the older and newer lines are very very similar architecturally. What applies to 3870 or 3850 crossfire should with a very small leap apply to 2900 crossfire too. Put it this way, I saw an article where a 2900 was crossfired with a 3870, with the 2900 as the primary card, and this mixing and matching actually worked. It didnt scale as well as to 3870's (this setup's performance was the thrust of the article) but the fact it functioned and scaled shows the similarities between the older and newer cards.

Well, hope that helps!
 

prolfe

Distinguished
Jan 9, 2005
247
0
18,680
0
Two 3850's would be cheaper and much less power-hungry. Also, the 3850's are easier to find than the 2900pro's.
 
Yep, go for the new 3850's or 3870's if you want to crossfire.
The 2900 series will die quickly now with the release of these new cards. I agree with TSIMonster, and I think you have picked out a really poor performance/price ratio in the 2900's and GTX cards right now.
 

spoonboy

Distinguished
Oct 31, 2007
1,053
0
19,280
0


Yeah that would be a good idea, much better than the overpriced and soon to be replaced gtx and the 2900's, for which no introduction is needed. Although if you could find either at a good price then it would be a workable option. For example on ebay.co.uk 2900 pros and xts often spring out of the woodwork, theyre much cheaper than new - of course - and they are, crucially, available. In the uk at least neither the 8800gt or 3850s & 3870s are broadly available as of yet, and prices can be quite high. If he could find a pair of 2900pros for say, under 230 pounds all in, he would have a powerful setup. He didnt say if he wanted to wait or not, although that would be the sensible option, ...and he hasnt written back yet. So whats your opinion blue frog?
 

blackened144

Distinguished
Aug 17, 2006
1,051
0
19,280
0
The CF setup does not always own the GTX. There are many games that dont support CF, so you only get the performence of one of those cards. Then there are other games that will not even run in CrossFire mode.. I forget who (I thought it was HardOCP but I cant find the article) but someone showed an article with The Good, The Bad (games not using both cards in CF) and The Ugly (Games that wouldnt run at all in CF).

As far as the OPs request, i would suggest you look at reviews and get the setup that plays the games you want best..
 

cleeve

Illustrious
Moderator


Depends how much they cost. At the same price as as a 3850, a 2900 PRO would be a great buy.

Chances are they're way more expensive than that though. Two 3850's or 3870's would be the way to go.

Having said that, the real alternative isn't the overpriced 8800 GTX, but a single 8800 GT... and it's hard to make any recommendations yet, before Crysis has released a patch that allows Crossfire to work.
 

wingless

Distinguished
Oct 23, 2006
156
0
18,680
0


I agree with this comment. The only way anybody would consider a 2900Pro at this point in time is if they have no clue as to how poorly they perform compared to the 3800 series. 3870's have much better power consumption, hardware UVD, and 2900XT performance at an unbeatable price. The 2900Pro is totally worthless.
 

spoonboy

Distinguished
Oct 31, 2007
1,053
0
19,280
0


The pro is, it would seem, nothing but a lower clocked xt, not even made of speed binned parts, and can reach xt speeds quite easily with overclocking, and up to the maximum overclock of an xt if flashed with an xt bios (or so i have heard).

If you could find one for under 130 quid, you can overclock it beyond the performance of a 3870. For the right price almost anything becomes worth the effort and cost.
 

Jakc

Distinguished
Apr 16, 2007
208
0
18,680
0


Uhm?

2* 3870 do perform much better than a 8800GTX, if CF works correctly in the drivers
You're not going to tell me that if 2* 3850 is on par with a GTX (read anandtech) 2*2870 is somehow less than a GTX.
 

Maziar

Champion
Moderator
As i said in games that support MultiGPU + a good Driver, then 2 3870 outperform a single 8800GTX

but for example, Crysis doesnt work with CrossFire so a 8800GTX beats 2 3870s

but for HL2:EP2 which support CrossFire, 2 3870 outperform a 8800GTX
 

spoonboy

Distinguished
Oct 31, 2007
1,053
0
19,280
0


Patience gentlemen patience. The drivers will come in time. did you not read my informative yet easy to pick up initial post?

laughs at self for being pompus.


...no really its a driver issue as to whether 2 X3870s beat a gtx, you can look at current benchmarks but then again you cant say that they are the be all and end all and thats that period. :bounce:
 

speedbird

Distinguished
Apr 19, 2007
547
0
18,990
2
My 2900pro performs just fine and anyone who claims the 2900pro is garbage, has zero clue what they are talking about.

However I do agree that the 2900pro is not worth the cash now that ATI's new cards are avaliable.
 

I would suggest 2 3850's because 2 equals a GTX in most games, the total price is about half the GTX, and the 3850 is DX10.1 with PCI-E2.0.
 

Blue frog

Distinguished
Nov 6, 2007
28
0
18,530
0
Thanks for the many points of view. Picked up 2 3850s for £212, i should get about £80 for my current X1950Xt on ebay so I think all in all a reasonable upgrade for £132.
Having looked at comparisons using 3DMark06 2 3850's beat a single 8800 GTX which is good enough for me.

I'm not bothered about Crysis yet, focusing on COD4 and GOW at present.
Cheers BF
 

Maziar

Champion
Moderator
I am not going to say anything more because no one listens, go and think that MultiGPU performs better than single card in every game,so i wont say anything, also there are tons of benchmarks (apart from hothardware) that 1 8800GTX performs better than 2 HD 3870 in games, i am not going to post them because no one listens, i am very sorry for u all who think that MultiGPU is always > single card
 

ASK THE COMMUNITY