Quick question on installing 6850

[NutterzUK]

Hi,
My two 6850s arrived today.
I have a quick question. I am using the Corsair tx650w PSU. One of the cables has two 6 pin connections on the end, which I used for my 4870. These cards only need one of these, am I ok to plug one into each, should I use only one of these connections, and use a totally new cable and the molex - 6 pin connector supplied to connect the second?

Really, I mean, are they both ok on the same cable as there are two six pin connectors that came on one of the cables with the PSU.

 

[NutterzUK]

One more question ( sorry! ).

The sides of the 6850 have gaps in, so hot air will come out the back and no doubt from the sides. I also have a corsair h-50 cooler, which brings air in through the back.

I have two issues.

1- the side case fan is right next to the 6850s, should I have this pulling air OUT, away from the 6850s side as they expel hot air? Or, should they be blowing air IN, towards the fans which are located on the bottom of the 6850s ( this may just blow hot air back into the cards? )

2- If these cards blow hot air out the back of my case, then above them, is my corsair h-50 radiator which has to pull air in ( or so the instructions say )... is this not going to just suck in what the graphics cards blow out?
I will post a picture or two up to describe my problem.

 

[Cleeecooo]

The side case fan should blow air out. You should be fine by using a single cable for both cards but i would recommend using two of those cables. I would contact corsair beforehand just to b sure. Maybe ypu could relocate the h50?

 

[NutterzUK]

I don't think it is possible to re-locate the h-50 as I only have one rear grill, unless I move it to one of the sides but I don't think there is enough space there.
The 650w tx only comes with one cable with 6 both 6 pin connectors on it. I used the molex to make sure they were getting enough power.
It seems I made a hash out of installing these cards!

1- The crossfire cable wasn't all the way pushed in, so the display didn't come on. I found and fixed this.
2- When I started it, all my lights came on, for a split second.. then it turned off again, then back on for a split second, and back off... etc etc. This worried me a lot... I decided it had to be a PSU thing, as there were no error beeps. I changed to the other 6pin connector, and its booted fine. Although after the whole restarting a few times it's cleared my overclock for me, but I can put that back in easy enough ( It has a place to save BIOS profiles so I just need to load it ).

So... It's just this second whilst typing this booted into windows for the first time.
I have that fan blowing out, as suggested. I was lucky it was already that way around, previously, it wasn't actually connected at all. My screen is going a bit mad with drivers, they need updating so i'm going to have to just fix that up and see if it's running properly.

Thanks!

 

[NutterzUK]

P.S I should re-name this thread, how NOT to install crossfire haha.

 

[NutterzUK]

Hmm, my top card is at 42 degrees idle, my bottom card at 36 degrees idle.. is this normal?

This is my old vs new Unigine benchmark

I see the min is very low, it had a stutter when it first started up. Is this an anomaly , or is this an issue?

 

[J.D]

Hmm, my top card is at 42 degrees idle, my bottom card at 36 degrees idle.. is this normal?

This is my old vs new Unigine benchmark

I see the min is very low, it had a stutter when it first started up. Is this an anomaly , or is this an issue?

Heat rises so it's normal to have a different temp.

Also let the test loop a few times to get your score. I don't run this test as I don't really care other than games but I've seen several people mention that the first run will sometimes not give a proper reading so let it loop a few times and it should show up fine.

 

[unp|dissy]

Hmm, my top card is at 42 degrees idle, my bottom card at 36 degrees idle.. is this normal?

This is my old vs new Unigine benchmark



I see the min is very low, it had a stutter when it first started up. Is this an anomaly , or is this an issue?

Wouldn't worry about anything you've mentioned here buddy, or those results

Enjoy

 

[NutterzUK]

Brilliant, thanks for your feedback!!
Now I just need some time to play games!