i done some investigating.....this should be made a sticky

Whatever. Do whatever you want. If you want to have your fans constantly blasting at 70-80% speed go for it.

Auto fan control in Afterburner has always worked great for me. It works even better when I create a custom profile.

 

@geeunit
Many guys had issues using 2 Xfire bridges. Only one is needed for 2 cards anyway.

 

like i said.
i put a TON of TIME and MONEY into finding this info out.

people should make this thread an important one so when people do a search for "low fps" or "stutter" or "fan changes speed causes slow down" or however you want it but its a pretty big find.

someone should probably pass it along to amd or something.

i think its narrowed down to the video card bios or maybe the driver.

its not hardware because when i set it to manual it does not do this except when leaving the gameplay (where it like flickers or switches resolutions or modes) on the way to the main menu.

i wish some other people would actually TEST this out so we could get some results.

alot of people are just talking stuff and saying this and saying that but no one is actually doing what i said to do so you could repeat the test.

i know it does it in crossfire when fan is set to auto and you are in the tank and blasting at point blank range into side of a hill or building and causing tons of smoke and debree.

all you got to do is have your sound turned down and listen for your video cards fans when it does the slow down.

its really pretty easy to reproduce if you have crossfire and bfbc2.

thanks and i hope someone can confirm this is happening.

 

i originally was only using one and it did the same thing.

2 didnt make any difference.

 

Be my guest. http://emailcustomercare.amd.com/

And please let us know what they say.

 

Nothing Personal and I'm not attacking you in any way ..

But Dude .. That is a tiny case ..
Your 'airflow' is completely cut off from the intake on the front by your ATI cards.
Your CPU is drawing HOT air directly from the ATI card on top.
Then on top of all that, your running that PC on a 680w PSU ?

Come on .. How 'cant' you have problems with that ?

 

I could have told you about this weeks ago if you had asked about the slowdown

BFBC2 uses extensive particle effects, IE - Same as Furmark does

Then tons of smoke/dust hits the game, the GPU shader goes apecrap trying to keep up with it and is prone to overheating very quickly

Like Just Cause 2 max GPU with my fan at 50% I hit around 59C on GPU shader, BC2 if I get tons and tons of dust/smoke effects my GPU shader shoots up to 66C in a very short timeframe

So yeah, you were hitting a thermal bottleneck with your videocards

EDIT: To poster above me, all cases with exhust at the top if you have them exhusting out the top, and not drawing air in through the top, hot air always rises from GPU to CPU no matter what

With high enough airflow it shouldn't make any difference, Furmark fully loaded my CPU only increases in temp by 1C and mobo by 2C

 

fyi when you join a game in bad company 2, most people get the sudden freeze up when the game starts and it isnt limited to one company or product. Also using 2 5870's in crossfire with a 3 rail pos power supply isnt conducive to a good gaming or overclocking experience. your gpus under full load with the cpu will cause slow downs because the cards cant get their max power draw (like when games first load or in demanding in game circumstances)

Edit* Also where is the airflow?

 

Yeah I can run two 5870's in Crossfire with my powersupply, but I wouldn't

 

I have a Corsair HX750w and about to get a second 5850. I have 3 hard drives and an SSD, DVD drive and 5 case fans (2 front, 1 side, 1 back, 1 top and the spec you see in my sig.

Am I gonna have problems?

I asked on G3D about 2 weeks ago if it would be enough and people assured me it would be.

 

Straight from Guru3d




Also @OP, if you are rununning two 5870's on that psu in your sig you are asking for trouble... it doesn't even have 40 amps on the 12v rails... Hilbert recommend's 60...

 

wanted to comment that but youve beaten me to it.

Read what he said you have numerous problems in ur airflow, as for the psu sounds a bit low for a quad or six core cpu with 2 gfx cards on crossfire.
Disable 1 and by that i mean completely take it off the case and try again to see if it still happens.

 

i run core temp to check my cpu and i run msi afterburner and all the temps are fine.

did you not hear me about when i said i adjust the vga fans on manual control and NO longer have the slow down.

i swear....if people would just read a little bit....this is not heat related well it is but i mean i not running too hot....75C is just fine for 5870`s under full load

just do the test i mentioned so many times before.

 

i thought it might be the psu too...its a 680 pure power by thermaltake...

when it does the slow down i thought well it possibly could be that but then when i set the fans to manual i do not get the slow down.

i think alot of people still think im having a problem..

the reason i named this thread what it is....is because i FIXED the problem...

that is why i started this thread

if it was the psu i would be having this problem still and i am not.

 

Thanks for that. But I cant really make out from that if its going to ok for me with my machine.

Like I say I have what is in my sig and 5 fans and soon to be another 5850. Of course I have a DVD drive as well.

This was the thread I asked in:
http://forums.guru3d.com/showthread.php?t=339464

Sorry, bit of a noob when it comes to power supplies etc...

 

"thermal bottleneck" with 66°C ? god....

EDIT:
cpu bottleneck
gpu botteneck
and now
THERMAL BOTTLENECK

whats the next? MOBO BOTTLENECK?

 

uhm.... mobo bottleneck are quite real u know?

 

Haha.. couldn't help laughing there..

 

Hey, i understand that and im glad ur problem is fixed but you must know that just because its working fine now doesnt mean itll be the same in few months, pushing your psu like that will get you problems in near future when it finally gives up and toast, that is if its running above the 680watts and if the 680watts is peak power and not continuous power.

Temperatures are still an issue even tough ur thermo sensors or however you call them in english look fine there are several other components that could be affected, vram, ram, motherboard southbridge and northbridge, hard disks and more... all these are affected by the temperature, if you really can afford money and its not a big deal for you i would strongly suggest at least a bigger case with more and bigger fans on it.

If you want your pc to last you must have it cooled down properly with no exagerated OC and Overvolt and also not stressing to much the psu.

So make sure that 680watts are really ok for continuous power and not just peak power.

IMHO peak power reference should be prohibited to be labeled but i supose the market tries anything for a sale these days...

 

you think im some kind of beginner?

i guess you missed the topic?


get back on topic and dont HI-JACK this thread please!


this topic is because i FIXED FIXED FIXED FIXED the problem!!!


anyone understand that?

pin this topic or put it in some kind of FAQ because this is WAS a problem and is NOW FIXED!


now on a seperate note:

to the people that talk about heat.

i say BLEH my TEMPS ARE GOOD!!!! just because yours are NOT doesnt mean mine are like yours....

look at the cpu cooler....CNPS10xtreme....read some reviews on it....cpu is fine....look at my gskill ram heat sinks....those are fine....

look at my airflow of my vga cards when they are at 85% they are FINE

ok so the heat is NOT an issue in MY rig.....



next we are onto my PSU......i guess you all paid a little to much for you big mammer jammer PSU`s didnt ya?

i been doing SLI since voodoos.....monster....i am no beginner...

my psu is rock solid stable even under furmark......heck under anything i throw at it.....

so can we get back to topic?

i asked for this to be a sticky so others could find information if they are having problem with the same thing.
thats all...

i did ask some of you to do this same test to verify...NOT ONE PERSON tried the test and to verify it...

cant believe it....

oh well guess you wont know the truth then will ya?