Crossfire questions

[sschlangen]

Im about to invest some serious money into my system and i was looking at the DFI Lanparty UT main board
http://www.newegg.com/Product/Product.asp?Item=N82E16813136009
and running two of these in crossfire mode
http://www.newegg.com/Product/Product.asp?Item=N82E16814195001
With a Aspire ATX 680 powersupply.
Now my question is will this setup work on these cards?
What real advantages will i have in todays games?
How much heat should i be worried about?
My case that im going with is the Gigabyte Aurora 3d. It has 2 120 mm fans in the back and one 120 in the front.
I read that not only is it important to have power but when you have AA enabled with a resolution bigger than 1280*1024 you need a proc that will keep up and i didnt know if the amd athlon 64 3000 could handle it for awhile or should i wait longer and go with the dual core amd fx60.

 

[the gamer]

Well first off you should wait alitte longer altogether because they new Ati R600 series cards are coming out very shorty (at the end of the year), but if you really want these then go ahead but you need to know a few things,

Firstly that motherboard you choose is a good motherboard (except there are some issue's with the layout on there that I dont like personaly), secondly you have to have an X1900XT and an X1900 Crossfire not an X1900 Crossfire/X1900 Crossfire (but I think you can use just 2 normal x1900xt's and it should run in crossfire because of the chipset), thirdly get an FX60 because that 3000+ cpu is going to bottleneck the card real bad uh and another thing the fans are ment to be loud especialy in crossfire setup, and the heat shouldnt be a problem with that Gigabyte case.

Another thing AMD is bringing out the new AM2 socket which is basicly the current 939 sockets just with DDR2 support, personaly I am not interested in it, I would just wait for the new videocards and get an Fx60 proccesser and that should do for another 3yrs (but that's my own personal options).

 

[Blacklash]

My opinions:

CPU support, dual core AMD X2 at 2.4 speed at least. You may get there via overclocking. X2 3800s are overclocking well now some up to 3.0 GHz on air. Option two for CPU, wait on Conroe. One in that family will cost just over 300usd and scream when OCed. Dual cores are the way of the future. Some games are already taking advantage of them and there will only be more. In addition they bring massive increases in speed when multitasking in windows. If you want a FX 60 I would wait for Conroe to hit and for some folks to dump theirs. There will probably be a a flood of them.

I would not put Crossfire on a 3000+ unless you are overclocking it to 2.4 or better.
IMO AM2 is not worth the switch or investment at this time, particularly if you already have loads of good ram on hand.

If I was limited to a stock 3000+ speed chip (.ie you don't overclock) I would get a single X1800 XT.

Crossfire and SLi are about 1600x and up with both AA|AF active. If you are limited to 1280x and below I would get a single X1900 XT and overclock it. I would not buy mid range cards and Crossfire them. Nine times out of ten a flagship or near flagship card will destroy them in real gaming. If you can afford two near flagship cards you are gtg. For example, Crossfire or SLi is worth it if you play at the quality settings I suggest and can afford; two X1800 XTs, X1900 XTs, 7900 GTXs, 7900 GTs that overclock to near 600|800.

You will see small gains with Crossfire at lower resolutions and nothing like at 1600x with AA|AF.

I don't know much about the PSU you list. I like PC Power and Cooling, and as alternative
Fortron Source.(Bluestorm|Epsilon Series) Here is a decent article about overclocking the X1900 that mentions PSUs.

http://www.madshrimps.be/?action=gethowto&howtoID=61

Nice detail of the Fortron Source Epsilon FX700-GLN:

http://www.xbitlabs.com/articles/other/display/psu-roundup_5.html

ATi Crossfire Certified PSU list, see the PSU tab:

http://www.ati.com/technology/crossfire/buildyourown2.html

Some people have had issues with the CFX 3200 and certain OCZ power supplies. The specifics escape me and I'd check around the official DFI forum about it before I got one.

I wouldn't cut corners on the PSU. It is vital to system stability and overclocking. IMO putting thousands of dollars worth of hardware on a crappy motherboard or PSU is moronic.

If your CPU is weak it will choke down your cards and limit them. In demanding games where you see Crossfire slowing down usually the CPU is the culprit.

Here is an example of what Crossfire can do on a rig with decent CPU support. "Single card" below is a X1900 XT. I was turning Crossfire off and on to measure differences at identical settings:

G.R.A.W Demo

Settings; 1600 x 1200, 16 x AF in game, CCC HQ AF option ticked, All game Options high, Mip settings in CCC highest quality:


Single card, Crossfire Off 34 FPS

Crossfire 67 FPS



Single card, Crossfire Off 38 FPS

Crossfire 75 FPS



Single card, Crossfire off 33 FPS

Crossfire 64 FPS



Single card, Crossfire Off 42 FPS

Crossfire 89 FPS



Single card, Crossfire Off 28 FPS

Crossfire 55 FPS



Single card 32 FPS

Crossfire 70 FPS


Crossfire is "worth it" provided you meet the conditions I set forth regarding gameplay settings and CPU support.

 

[Croak]

Im about to invest some serious money into my system and i was looking at the DFI Lanparty UT main board
http://www.newegg.com/Product/Product.asp?Item=N82E16813136009
and running two of these in crossfire mode
http://www.newegg.com/Product/Product.asp?Item=N82E16814195001
With a Aspire ATX 680 powersupply.
Now my question is will this setup work on these cards?
What real advantages will i have in todays games?
How much heat should i be worried about?
My case that im going with is the Gigabyte Aurora 3d. It has 2 120 mm fans in the back and one 120 in the front.
I read that not only is it important to have power but when you have AA enabled with a resolution bigger than 1280*1024 you need a proc that will keep up and i didnt know if the amd athlon 64 3000 could handle it for awhile or should i wait longer and go with the dual core amd fx60.

To truly take advantage of Crossfire or SLI, you need to be running at higher resolutions, as Blacklash has already stated. When I was running 1680x1050 with everything on max, Crossfire didn't have a huge impact on framerates, a single X1900 was getting nearly the same framerates in most games.

When I moved up to 1920x1080, I NEEDED the Crossfire setup to maintain good frame rates, a single card would start to choke unless I reduced the image quality settings.

Just as a data point, playing a slightly less than modern (but still demanding and popular game that REALLY benefits from cranking up IQ settings) Battlefield 2, at 19x10 I tend to average about 75 FPS with Crossfire...and about 50 without. I know, 50 still sounds pretty playable, but it's really not. The issue is, I never see lower than 60FPS with Crossfire, whereas I'll dip as low as 20ish FPS with a single card, which can mean a free trip back to your spawn point...it's all about the area under the curve.

Your power supply should be more than enough to support two X1900's, I'm doing just fine with a 530w Enermax PSU. Of course that depends a lot on the quality and design of the PSU.

Heat WILL be an issue. Adding a second X1900 raised my case temps almost 10c, and idle temps on the first card went up 8 degrees. Part of the case temp increase is because the board I'm using (Asus A8R32-MVP) places the southbridge and temp sensor right between the two PCI-e slots, so it's sitting there sandwiched in a hot area. Be prepared to throw a lot of fans at the problem, or water cool if you can't stand the noise.

And yes, you need a good processor. Dual core isn't absolutely necessary, but it's a lot more future proof than a single core, and you'll notice some very nice benefits just using Windows with a dual core, and more games will be taking advantage of them in the future. At a minimum I'd recommend a 3800+ if you plan to OC...if you want to run at stock speeds, I'd say go with a 4400+ or any of the Opterons, the larger 1mbx2 cache does help performance. BTW, this system replaced a 3000+ A64 754 setup...don't stick with that 3000+ if you can avoid it.

Finally, I'm not one of those "wait for the next gen" guys. A bird in the hand, and all that...life is short, if you enjoy gaming and enjoy geeking, and have the scratch, buy NOW, there might not be a LATER.

 

[R1ckCa1n]

Im about to invest some serious money into my system and i was looking at the DFI Lanparty UT main board
http://www.newegg.com/Product/Product.asp?Item=N82E16813136009
and running two of these in crossfire mode
http://www.newegg.com/Product/Product.asp?Item=N82E16814195001
With a Aspire ATX 680 powersupply.
Now my question is will this setup work on these cards?
What real advantages will i have in todays games?
How much heat should i be worried about?
My case that im going with is the Gigabyte Aurora 3d. It has 2 120 mm fans in the back and one 120 in the front.
I read that not only is it important to have power but when you have AA enabled with a resolution bigger than 1280*1024 you need a proc that will keep up and i didnt know if the amd athlon 64 3000 could handle it for awhile or should i wait longer and go with the dual core amd fx60.

Crossfire is only useful at resolutions 1600x1200 and above with AA/AF applied. Unless you plan on this type of gaming, maybe a single card and use the extra cash to get a faster CPU. What you will find is most games are CPU limited.