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two 3870x2 Crossfired on X38 Maximus Formula board ?!

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November 19, 2007 7:57:46 PM

Hello guys,

Building my Crysis PC and it's not even finished and I'm already doubting my choices. What I so far bought :
---> Asus Maximus Formula SE X38 mobo (2x full x16 pci-e). Will be delivered tomorrow or so
---> Q6600 G0 stepping. Not installed yet but already lapped :)  (to kill some time). Gonna OC this one
---> Thermaltake Ultra Extreme 120, lapped with SilenX 120x38mm fan (90cfm or so)
---> 2x 2x1GB Corsair XMS2 6400C4 with DHX heatspreader. So 4GB DDR2 Cas 4
---> 1200W Thermaltake modular PSU (W0133). I know it's overkill, but better overkill than underkill in my book :) 
---> Coolermaster CM 690 with like 5 casefans (also one on right side blowing on back of mobo)
---> Vista Home Premium 64bit
---> rest from my old pc.

Now the big questions isssssssssssssss :

I was planning on Crossfiring 2 HD3870's but now all of a sudden I hear of the January '08 3870x2 which sounds really tempting. Call me crazy but I will want two of those (know it's not really economical but probably I have some defect or so :bounce:  ).
Anyways, I've been reading on this new CrossfireX 790 AMD chipset mobo that you'll need for tri and quad CFX. But will I be able to just plug 2 3870x2's in my Maximus Formula X38 mobo ? Or will the 2x dual gpu vidcards be seen as 4x gpu and thus quad Crossfire X for which you need an AMD 790 mobo ?
I mean it would be kind of strange if 2 3870x2's Crossfired would only work on 790 AMD mobo (with AMD processor).

If Maximus Formula will support 2x 3870x2 I have a winner but if not I have to return mobo asap upon receipt and wait for Intel chipset that does support it (if at all). If no supportive Intel chipset will come then it's a pitty and cancelled altogether. SPIDER is a cool marketing term but I'm for sure not going AMD processor and AMD mobo.
I mean if you HAVE to buy everything from AMD and no room for customization whatsoever AMD could just as well start building consoles where everything is already put in together.

Shorter version : will X38 Asus Maximus Formula mobo support 2x 3870x2 vidcards ?
November 19, 2007 9:36:35 PM

If the new video card is Crossfire ready, it will run in any Crossfire mobos. But I don't see a Crossfire link included with the mobo. You may have to buy one.
November 19, 2007 9:40:09 PM

No idea don't own one. But it'd be kind dumb for it not be supported.
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November 19, 2007 10:06:14 PM

I'm not sure if this info has been released or not officially. I would think that the dual-gpu-core 3870s will run in x2 CrossFire just fine on the X38 mobos because 2 of the PCIe lanes are 16x and 2.0, while on the new AMD chipsets (790) I think you're getting all 4 PCIe lanes @ 16x and 2.0.

So basically I'm coming to the conclusion that the dual core 3870s will work just the same on the X38 as the 790 as long as you only have TWO running in CrossFireX. If you wanted to run FOUR, you would have to have the 790 chipset from AMD.
November 19, 2007 11:01:07 PM

go for it
November 19, 2007 11:35:59 PM

Well, I'm seriously considering swapping the 8800 GTX on my x38 mobo for 2 3870's. At 1920x1200, full high video settings I'm averaging 10fps in Crysis, not acceptable lol w/ a qx6850, 4 gb of ram both clocked at 1333MHz. So realistically the only thing bottlenecking my system is the single GTX.
November 19, 2007 11:39:08 PM

First of all... 2x 3870 CAN BARELY KEEPS UP WITH THE 8800GTX IN MOST GAMES THAT ULTILIZE CROSSFIRE. Don't do it. Even if you switch the 8800GTX will probably still perform better.
November 19, 2007 11:59:47 PM

How about you get one 3870 now, and when 3870x2 comes out you can buy it and crossfire it with the 3870. Not quite 4 graphics cards working for you, but you wouldn't have to wait this way, and I'm sure the power of 3 3870s will be plenty of power for most games.
November 20, 2007 12:24:14 AM

how about he buys the super cheap 3850 256mb and then when 3870x2 is out, sell the 3850 and use it for the x2
November 20, 2007 1:21:05 AM

itotallybelieveyou said:
First of all... 2x 3870 CAN BARELY KEEPS UP WITH THE 8800GTX IN MOST GAMES THAT ULTILIZE CROSSFIRE. Don't do it. Even if you switch the 8800GTX will probably still perform better.


Not exactly true though. From recent benchmarks we can see that the 3870cf when pushed far enough ie: high resolution and on a x38 board that fully utilizes x16 lanes it beats the gtx. And the 3870cf cost just about or under 1 8800gtx. And the newer drivers have yet surfaced either. And it will consume less watts then a 8800gtx, on top of that all the new lines of ati cards run 3d, and 2d imaging programs way better then new line of 8 series cards(check out the new quadro vs firegl, same chips different drivers). So for any body with a x38 board I fully encourage them to get a pair of 3870cf and when the 3870x2 comes out you can sell yours. Because not everyone plans to upgrade their mobo.

Other then that. I plan on using a 8800gt because I got mines for cheap and I don't need that much extra power =D
November 20, 2007 2:13:07 AM

akhilles said:
If the new video card is Crossfire ready, it will run in any Crossfire mobos. But I don't see a Crossfire link included with the mobo. You may have to buy one.

Crossfire cards come with crossfire bridges not the mobos
I think dual 3870s x2 will be similar to the GX2s that came out (although apparently the performance increase wasn't that great in QuadSLi)
November 20, 2007 3:18:47 AM

akhilles said:
If the new video card is Crossfire ready, it will run in any Crossfire mobos. But I don't see a Crossfire link included with the mobo. You may have to buy one.


The crossfire connector comes with the video cards, at least that's the way the ATI camp has been handling it. Nothing should have changed with its most recent release of HD series.
November 20, 2007 7:23:13 AM

Thanks for all feedback

I guess the X38 can handle 2x 3870x2 and I'll keep the board

Either I'm just waiting with my 1900xtx for the 3870x2's to come out or I'm buying 1 or 2 3870's for the meantime.

Only thing is I think the latter would be a bad investment because 3870 will not be worth much 2nd hand in a couple of months (I reckon).

On the other hand building an enthusiast pc is a bad investment altogether :sol:  so that's no argument :kaola: 
November 20, 2007 4:19:57 PM

jevon said:
I'm not sure if this info has been released or not officially. I would think that the dual-gpu-core 3870s will run in x2 CrossFire just fine on the X38 mobos because 2 of the PCIe lanes are 16x and 2.0, while on the new AMD chipsets (790) I think you're getting all 4 PCIe lanes @ 16x and 2.0.

So basically I'm coming to the conclusion that the dual core 3870s will work just the same on the X38 as the 790 as long as you only have TWO running in CrossFireX. If you wanted to run FOUR, you would have to have the 790 chipset from AMD.


I agree that it should work; I mean it's 2 vidcards on a crossfire mobo so it should work, but I thought the dual GPU per vidcard might register as 2 gpu's, so 2 vidcards of those will have 4 gpu's registered for which you need a 790 chipset (even though it are physically only 2 cards and not 3 or 4 for which you for sure will need the AMD 790 Spider platform).


This is what causes my doubts :

" One of the coolest features of the Radeon HD 3870 X2 is that you don't have to get a higher priced AMD 790FX chipset powered motherboard with 42 PCI Express lanes to run a pair of Radeon HD 3870 X2's. This means that this can run on lower priced chipsets like the 790X that offer just two x16 PCI Express slots. "
http://www.legitreviews.com/article/593/1/

It only speaks of 790 mobo's

Been surfing and there really isnt a lot of info on this available. Why doesnt ati shed some light on this because with Crysis out and the 3870x2's ready to launch it seems vital information for anyone planning on building a game pc.

All in all I still expect it to work because by limiting 2 3870x2's only to AMD 790 mobo's with AMD procs, ATI-AMD would shoot themselves in the foot as way less 3870x2's will be sold (on the other more 790 mobo's will be sold).

I just want to know for sure
February 4, 2008 9:13:56 PM

Ok, still playing with the settings but it looks like a lack of driver support for Vista x64 to enable 4 GPU crossfire on an X38 mobo. Currently using two Diamond Viper 3870x2, all 4 GPU's are recognized in the Hardware settings using ATI's 8.1 driver w/ hotfix.

Intial tests with Diamond's CD version driver showed the following results in 3DMark06 default settings for a single 3870x2:

15719 Performance Settings
9395 Image Quality Settings

The Crossfire section is displayed in the Catalyst Control Center but there is no option available to enable, configure or run a diagnostic using Crossfire.

Ran another 3DMark with Cat 8.1, both cards connected with the Crossfire cable and scored 11804 so obviously software support is still lacking atm to get all 4 GPU's optimized, for Vistax64 atleast. I'll keep looking for a Beta version if available and post the results, but in the meantime it looks like 3870x2 should be able to be crossfired on an X38 mobo.


February 4, 2008 10:17:06 PM

There is a modified leaked 8.451.2 driver version available for download that the hardware sites have access too for Crossfire testing but unfortunately it doesn't recognize my hardware lol.
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