3870x2's in crossfire Problem???

[shortbus25]

All right never really done this whole forum thing before (NEW) but have a serious question!! Just recently got a great deal on two brand new Visiontek 3870x2's on

Ebay ($130 each) Never opened I had to break the plastic! But my question is ok I put one in my pc for about a week and let me say that yes they are awesome but

decided to try out the second in crossfire even though my psu shouldn't be able to handle it! Well its working for now and from what I've read I should be getting bsod's

and frequent lockups and games cutting off restarts ect ect. This psu is a Cooler Master RS-500-PCAR which is now only rated @ 500watts (Mine is over two years old but

I take care of stuff so when I got it 600Watt is what it said) anyway the problem I am having is not about speeds at which everything works but FPS That are really not

that much better than a single X2 I have ran riva tuner while playing some games and will either read only two gpu's have activity or they all have partial activity like say

25% on all 4 gpu's (=100%)? The mother board is dual 16x pcie single but in crossfire its 16x + 4x pcie could that be the reason or is it underpowering the cards also im

not playing at high res 1440 x 900 so i should pump out some fps new drivers installed the hole 9 yards!

Games are as follows: Gears of war :90fps solid, bf2142 :110fps solid, cod 1,2,4 :100fps solid waw, far cry 2: everything on high dx10 30-40 fps, stalker clear sky: dx10

high 30-35fps, dirt , timeshift, crysis :flickers on anything above medium but on high is around 30-40fps, world in conflict 40-120fps up and down like a yo-yo.

Do none of these games support quad gpu's or is there something i need to turn on?



Sytem specs

Processor: Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz (4 CPUs), ~2.4GHz
Memory: 8190MB RAM
Hard Drive: 500gb WD SATA II / 160gb WD IDE
Video Card: Dual Visiontek ATI Radeon HD 3870X2 (Quad GPUs) ( Just for bragging rights really)
Monitor: Hanns-G 19"widescreen lcd
Sound Card: Realtek Digital Output (Realtek High Definition Audio)
Speakers/Headphones: Logitech X-540 5.1 Surround Sound/Logitech Precision PC Gaming Headset
Keyboard: Saitek Cyborg Keyboard (HID)
Mouse: Microsoft USB IntelliMouse Explorer 3.0
Mouse Surface: IDEAZON World In Conflict Fragmat
Operating System: Windows Vista™ Ultimate (6.0, Build 6001) Service Pack 1 (6001.vistasp1_gdr.090302-1506)
Motherboard: ECS P965T-A Crossfire 775 Intel (16x pcie - 16x + 4x crossfire)
Computer Case: Winsis WB-18 Black/ Silver SGCC ATX Mid Tower Computer Case With 600 watt CoolerMaster Sli-Crossfire Rated power supply






Someone please help me figure this out is my crossfire not working or what????

 

[shortbus25]

OK I know after 70 somethin reads someone knows whats up? All I want are suggestions by the way tryed 3dmark vantage and posted a score of 18817 didnt submit but wanna run again anyway?

 

[marxtinus]

Multi Gpu is a more sophisticated technologie than that. It's not like throwing a GPU more to get 100% gain of fps. First thing about multi GPU technologi is about the ram. In your case you probably got two 3870 X2 with 1 gig memory each. In fact, you may consider your card as 512 mb of ram beacuse each video card has to have the whole set of textures loaded in to render the image. Be carefull when you set texture details in games beacuse adressing more texture memory than you've got will make it swap to system memory and you'll loose plenty of fps in the process. Most of the time, you only need to lower texture details with all other options cranked-up to get good performances. The second thing is about the rendering methode. in a Crossfire or SLI config each GPU will render a part on the entire image. In some case, all the job would be done on a single card while the other GPU waits for the scene to be completed. I might be wrong but, there's no load balancing technology involved in multi-Gpu rendering. In fact, in first gen of Crossfire ATI tried to implement a load balancing system but it was pointless because of the ressources used by such system.

 

[shortbus25]

OK I get all that but even not setting textures to high what kinda quality will that add to the game. Its like your saying to get more performance lower down the settings of the game. But then wouldn't it be pointless to even have crossfire or sli if you have to lower your settings all im saying is if there is no performance gain from one card to two then what would be the reason fro anyone to even consider crossfire. Yeah its cool and you can brag to your freinds but if you have to lower setting in game to get improvement then you can do that with one card!

 

[marxtinus]

The textures sharpness (quality) is only one of multiple factors in general rendering quality. by adding GPU's you will add calculation possibility and that mean you be able to push Antialiasing,Anisotropic Filter, Particules and world details to higher level without compromising on FPS. With bigger screen (and resolutions) comes better chances to see the true differences between simple and Multi-GPU. For my part I got 1 3870X2 and 1 3870 in CFX on a P45 chipset wit 2.4 quad-core (same as you do). I might suggest you to overclock your CPU a bit. Especialy on Far Cry 2 and GTAIV I've seen a HUGE difference while running on overclocked frequencies (3.1). As a conclusion, your right. Ati 3870 is'nt the card of the year in 2009 but one year ago, a 4870 worth about 800$ and scored under a tri-3870 solution for about 500$ so that is what I brought home. After one year of tweaking I can say that there is absolutly no cogency in performances from games to others. Crysis (incredibly poor), COD(incredibly good), Far Cry 2 (really Nice), L4D(WOW), Fallout(passable) GTAIV(disapointed). Usually, a patch partially solve the problem in the game when anyway you've got bored to play it.

Finally, I think it's work fair enough to get stuck with it for a while. Each time I buy a new game I need to tweak the settings until I've fond the good recipe but I'm not afraid by that and thrully, it's a part of the game (Lego invented it). By the way new games make better use of Multi-GPU as Multi-core ether.

I'll try to post some Benchmarks.

 

[shortbus25]

Yes all true tweaking it out is what its all about but to see your second set of gpu's idle 99% of the time is disharting. I also tried the tri-fire set up like you and still did not notice any gain of the secong gpu actually being active. As far as benchmarking well I've ran all the test read all the reviews and still cant figure out what is going wrong and why! Contacted mb company and they say video card and vise versa! I think its ATI's fault for not getting the drivers to work right without have to adjust them to our own benifit when i turn on crossfire i want to see gains what ever they are. I didnt get this setup just to stress out my psu!!! Also I am upgrading psu's going with a xion 1000watt 6 12v rails hopefully this might help!!!

 

[The_Blood_Raven]

Honestly that performance sounds about right since a 3870 X2 is slightly ahead of a 4870 512mb, and the crossfire wont scale as well.

 

[marxtinus]

Just wondering, what have you used to get GPU Activity ?

 

[shortbus25]

crysis somewhat and suprisingly cod 1,2 use a four cores but cod4 no. really thats about it and crysis run better with 2 then 4 so its not even worth it looks like crap gotta turn the textures to low everything else can be high. I just dont know what the real issue is!

 

[marxtinus]

Crysis is a case by itself! far cry 2 runs flawlessly on crossfire 3870x2 on the same f... engine. Don't try to conclude anything from crysys stats. It's been program for nvidia card and this f... game works only on thoses. You wana play Crysys? grab a N6600gt It will work bether than quad 3870 for shure. The Issue is Crysys but Hey, there plenty of games out there that worth playing... don't get stuck on this one!

 

[marxtinus]

I've experianced problems with croosfire but it was in fact a hardware problem. Are you 100% shure about your hardware. Double check your video card maybe...

 

[shortbus25]

yes im sure both cards will run cod4 @160 fps but together a tad bit slower and when you turn aa on with both in crossfire about 80fps is all youll see and that is only @ 2x aa