Crossfired x1950 pros = LESS performance

Having recently acquired a second x1950pro i thought i would get some serious performance increase by crossfiring them in the ep45-ds4 mobo.

After some trial and error about internal connectors CCC now tells me that crossfireX is enabled - i am using 2 internal crossfire cables.

Device manager states that all display adapters have drivers and are 'working correctly'.

However CPUID Hardware Monitor only shows one 1950. CCC also only has one 1950 in the drop down menu

When i have crossfire enabled i get noticeably worse performance playing games - CS:S, FA, rFactor.

I tried using the second 1950 as a secondary adapter to drive another monitor. Connected it to a 1280x1024 samsung and set it up in displays and put itunes visualiser full screen and put FA on the main screen. xfire disabled

FA played utter crap till i turned off itunes then it played ok.

Possible solutions that i cant find the answers for online.

Power - i have 540w and i have read the 1950 uses 180 loaded but in crossfire 2 use 277w. This should be enough - just but enough.

Bottleneck - i have 2GB ram but only value 533 so maybe that's a bottle neck.

Only one 1950 functioning - why does CPUID and CCC only show one 1950?

PCI-E 2 8x - the board has two PCI-E 2 slots but when crossfired they run at x8 and not 16. The 1950 is PCI-E 1 x16. I have read and been told that a PCi -E 1 x16 device will run at the same speed in a PCI-E 2 x8 slot. ??

Any enlightenment would be appreciated

No clue why it would be killing your performance, but besides that.

Why run the cards seperate for 2 monitors, once you get the CF figured out just enable 2 monitors from the 1st card. Also 540w should be plenty enough with your Q6600 at stock clocks. I'm doubting the ram is your bottleneck, and no 1 card in a pci-e 16x will not be as fast as 2 cards in 8x slots. Even new cards don't cap out the bandwidth of PCI-E the older x1950's defineatly can't so really it won't matter. Bad comparison but a escort won't go any faster down a 4 lane freeway than it would down a 2 lane

run 3dmark 2006 with 1 card and 2 cards, see if the score changes?

Ok thanks,

So the pci-e isnt the problem - that's good. lol that's a good comparison.

The only reason i was running the second monitor directly on the second card was to try and get some clues as to why the crossfire aint happening. Mainly to see if the 2nd card is functioning...

I have tried video stress test for CS:S and the results are the same 126 - 127fps.

I thought about 3DMarks but thats expensive?

My main suspicion is the lack of a second card in CPUID and CCC,

you can download trials of 3dmark for free, give that a shot.

Download GPU-Z and see if it says they're running in Crossfire. Also check your cards temps. They might be downclocking if they're running too hot, or if your power supply isn't up to the task of powering 2 cads.

well tried gpuz and it shows 2 cards and it also says that crossfire is enabled.

i thought i'd leave the temp graphs going while i ran Forged alliance. crash. first time i can remeber fa crashing the whole system.

woah its done it again,

try a third time

Sounds like a power problem to me what kind of power supply do you have? 540w but what is it?

In fact it's only 520w,

TACENS RADIX II 520

I have had to use a 4pin to 6pin/pci-e adapter to power the second card.

i have also noticed that the second card - well what i THINK is the secondcard it's ahrd to tell as they are both called the same in gpuz - is always running 5 degrees lower than the other card.

I think it's only started crashing since i've tried it with gpuz on.

I'd try another power supply before anything else. You've got good hardware and you don't want to lose it to a bad power supply.

This time i started FA first for a bit than shift-esc out and opened gpuz

the first card was at 63c and the second was at 53c (GPU temp)

so the 2nd cards not working hard 53c is idle temp.

either it hasnt enough power or it isn't being told to do anything. i went back into FA with gpuz running and it crashed straight away.

i'm going to try CCC automated clock config wotsit and see how the two cards temps go.

If i have to get a new psu trap i will but i've just bought this one.

Raidmax are bottom of the bin powersupply providers, if you can call them power supplies, more like power-kabooms.

Check your amps, those old x1950 pro's are tough as nails, but if I remember right they need 28amps. I ran my x1950pro for a full year on 25amps and it would artifact now and then and it finally gave up the ghost. Lasted me till my next upgrade, very reliable card even under amped, but your running 2 and it sounds like the PSU has the wattage, but if you had to add an adapter to get the 2nd hooked up I am willing to put down money it won't have the amps to run both cards. I don't know why I didn't think of that before.

**EDIT** Also if your idle temp is 53C you might want to pick up some more case fans, thats a pretty high idle temp, you should be looking for high 30's on that. Also don't try CCC clocking all that does it overclock the cards, it won't downclock them for lower amps or watts. So doing that will only make the problem worse.

Also did some research, you do have 2x 12V lines, but line 1 is 17A and line 2 is 18A, which isn't enough for 2x x1950pro's, I can almost garanttee that is your problem.

Yea man you need a new PSU. Check the Cyber Deals for a hot deal on a Corsair TX750.

Radix = Raidmax? I dunno

It says on the power supply box that max amperage is

28A 28A 17A 18A 0.8A 2A

So i'm presuming that the 4pin i have my adapter (6pin pci-e) in is possibly the 17A or the 18A?? That would make sense.

Enlighten me i don't know about this stuff.

My system only crashes when i run gpuz at the same time as straining the graphics card/s.

As for temps - 53c isnt a good idle temp? It does say on Hardware Monitor that all the other main temps including the q6600 are around 33c.

I think 53c idle for X1950 Pro is decent actually I believe he misread the post.

Have read your edit kurgan and it makes sense.

In fact now i remember that the adaptor is a 2 4pin to 1 6pin affair and i have both 4 pins connected.

It would seem that i need a new psu.

this is DEF a power supply problem, those x1950pros sucked alot of amps. 28amps per card, + amps for the rest of your system? your psu wont cut it.

So can anyone tell me what's a good power supply for my needs then.

I am planning to overclock pretty much every component in future so it would be nice to have ample power and amps to do this.

The TX 750 has been mentioned - any others?

This would also be a good choice: http://www.newegg.com/Product/Product.aspx?Item=N82E16817703019