Urgh...how do I Crossfire these two 7970's?

M

MeatballCB

Weaksauce
Joined
Oct 8, 2008
Messages
124
Hoping to pick some brains and see if anyone has any ideas. Here's my situation.

Picked up 2 Sapphire Radeon 7970 OC cards on Newegg to replace a pair of Radeon 6950's I had Crossfired on a MSI Big Bang Fuzion motherboard. The Big Bang has 3 PCIe x16 slots. There's 2 card slots (1 PCI x1 & 1 PCI) between x16 slot 1 and 2 and one PCI slot between 2 and 3.

The 7970 OC's are not double width cards. The back plate is double width, but the fan assembly sticks out at least another half a slot width and the fans are mounted on the side of the assembly.

When I run any of the cards by themselves, they can easily be overclocked to 1100/1500 on air without a problem. Even at 100% load they only get up to about 75C at around 80% fan.

When I put the two cards in and crossfire them in the first two PCIe x16 slots, they about near touch and that of course chokes off the air flow for the fans on the top card so it doesn't cool. At 100% load within 10 seconds or so it's at 85C and climbing.

I tried to space the cards out and put one in PCIe x16 slot 1 and one in slot 3, but the Crossfire bridges aren't long enough even though they are the 'Long" 100mm bridges. They're just not long enough to cover the 5 slots to get to the slot 3 card. I've searched all over and I can't seem to find anyone that sells any bridges longer than 100mm. I did find a reference to an ASUS 127mm bridge, but it's not listed on their store and I can't find it anywhere.

So...does anyone have any thoughts? Should I just return them both and wait for the upcoming 7990 :)
 
Last edited:
imo, water cooling is your next best option...

a RX360 rad would have enough surface area for both GPU's. I used to run a 6970 on a 240 slim rad but it wasn't enough when I added my Q9400 to the loop.
 
Aftermarket cooled cards are a really poor choice for SLI or crossfire. Best you can do is attempt to improve case air flow with more fans, or increase your manual fan speed to 100%. (which should be inaudible on some aftermarket coolers)
 
If you have an OCN account, you can pm this guy and pickup an H60/ Bracket for one of your cards (or both ;))

If you got it for both, you would see a lot better temps, and it shouldnt cost more than 150 max.
 
Remove the plastic shroud from the heat sink and use a side case fan to blow cool air on them.
 
Wow, what a design fail. Stupid me, I'd probably cut a section out, but it's probably better to just remove the shroud and call it a day like the previous poster says.
 
Unfortunately, removing the shroud is not an option because the fans are side mounted as well. I can probably go with water cooling, but I hate to pay another couple hundred more bucks when all I need is to find someone that makes a 5" long crossfire cable :)

I still have 2 weeks left to return these bad boys, and I'm probably just going to do that and get a different model instead of spending a ton of money on it.
 
Have you tried contacting the Sapphire to see what they can do for you? if they don't have a solution, I'd return it. The longest bridge I've used was the 10cm bridge and you're right, I haven't seen anything longer than that...
 
Yeah, bounced some emails back and forth with Sapphire and they didn't have any other options. They actually told me to check with Asus. I _think_ Asus has a few options, but not sure if they'll work. And from the pictures, I'm thinking the bridge I have is the 3.3" bridge.

I assume the measurement is from connector to connector and not the length of the entire cable. If that's the case, mine's about 3.3" (84mm), so I'm going to order the 3.9" (100mm) bridge ASUS has.

Apparently they might also have a 5" (127mm) Crossfire bridge (Part number 14G030025906), but it's not here in the US. They're checking if they can actually get it and going to contact me.
 
When going SLI/CFX, you always want reference cards or water cooling. Let this be a lesson to you :p
 
christ, just wedge some freaking pencil erasers between the cards and stop giving bad ass cards 3 eggs on newegg because you can't manage to use them in crossfire.

Either add a fan blowing across the cards fromt he rear of the cards, or put some pencil erasers between them to add a gap for air movement. Preferably both.

3 eggs for a perfectly amazing card because you can't manage to crossfire them? really?

in the old days, people didn't blast a card, they improvised and then posted about how awesome they were.
 
stealthy123 said:
christ, just wedge some freaking pencil erasers between the cards and stop giving bad ass cards 3 eggs on newegg because you can't manage to use them in crossfire.

Either add a fan blowing across the cards fromt he rear of the cards, or put some pencil erasers between them to add a gap for air movement. Preferably both.

3 eggs for a perfectly amazing card because you can't manage to crossfire them? really?

in the old days, people didn't blast a card, they improvised and then posted about how awesome they were.
Click to expand...

Crossfire is a major feature of the cards. And no, people did not accept having no reasonable solution. Even if he rigged a halfassed setup like you're suggesting, it is not a real fix and wouldn't even help the issue much.
 
Most people who can spend $1,000 on graphics cards can afford to water cool them =).
 
af22 said:
Most people who can spend $1,000 on graphics cards can afford to water cool them =).
Click to expand...

Or know what the heck they are doing.

Do we even know what case this guy has? Case design plays a HUGE role in CFX/SLI temps....
 
Case I have is the Rosewill Thor V2 which is great for air flow, that's not the problem. The problem is the card is too wide with it's fan configuration to Crossfire in the most common x16 slot setup and noone makes crossfire bridges long enough to span to a third slot so you can open up some space between them.

Erasers eeking out an extra 1/4 of an inch of clearance won't do squat when I want to do folding on the machine when it's not in use and the cards are running consistent 100% load.

Amazing how quick a request for some ideas goes to me not knowing what the hell I'm doing. :) I've been building my own PC's since the 286 days, I have some basic ideas on how to put together a machine :)
 
85C isn't that bad... You'll probably end up with higher temps if you replaced them with reference dual slot cards.

Also depending on your mobo if you put one of those 7970's in the third PCIe slot it might be bandwidth limited.
 
turn your fans up? or install better cooling. i have no heat problems with my 3 triple slots... just amd driver problems :D

attachment.php
 
GoldenTiger said:
Crossfire is a major feature of the cards. And no, people did not accept having no reasonable solution. Even if he rigged a halfassed setup like you're suggesting, it is not a real fix and wouldn't even help the issue much.
Click to expand...

why on earth do you even open AMD threads?

So putting some space between the cards and adding a fan isn't a real solution? Don't pretend you are here to help the guy, you wanted another chance to lambast AMD, just like every other post of yours in the vidcard section.
 
MeatballCB said:
Case I have is the Rosewill Thor V2 which is great for air flow, that's not the problem. The problem is the card is too wide with it's fan configuration to Crossfire in the most common x16 slot setup and noone makes crossfire bridges long enough to span to a third slot so you can open up some space between them.

Erasers eeking out an extra 1/4 of an inch of clearance won't do squat when I want to do folding on the machine when it's not in use and the cards are running consistent 100% load.

Amazing how quick a request for some ideas goes to me not knowing what the hell I'm doing. :) I've been building my own PC's since the 286 days, I have some basic ideas on how to put together a machine :)
Click to expand...

so wait, you won't try a potential solution because you know it won't work before you try it.

Good luck with that.
 
Who said I didn't try it? I already have, there's just not enough of a gap to feed those two side mounted fans.
 
stealthy123 said:
why on earth do you even open AMD threads?

So putting some space between the cards and adding a fan isn't a real solution? Don't pretend you are here to help the guy, you wanted another chance to lambast AMD, just like every other post of yours in the vidcard section.
Click to expand...

Really? I'll just put this here as I can't think of anything else to: :rolleyes:

And no, rigging up a pencil eraser to bend your cards apart is not a real solution. Linking him to a long crossfire bridge or coming up with some other alternative, sure, but that? That's just ridiculous.
 
GoldenTiger said:
Really? I'll just put this here as I can't think of anything else to: :rolleyes:

And no, rigging up a pencil eraser to bend your cards apart is not a real solution. Linking him to a long crossfire bridge or coming up with some other alternative, sure, but that? That's just ridiculous.
Click to expand...

There are no long crossfire bridges. this mythical product you refer to, it doesn't exist.

And fyi, pencil erasers are not a ridiculous solution to his problem. They are a proof of concept solution, and if he later decided he wanted to space them out with fucking diamonds, he could do so and surely earn your acceptance and high fives.


the only ridiculous thing in this thread is your postings.
 
I run crossfired 6850s in my main rig, and fyi, they have pencil erasers spacing them out, because until I did that I wasn't comfortable with the temps.

but ya, it's not a solution, it's a ridiculous idea that has no factual or experiential basis.
 
MeatballCB said:
Who said I didn't try it? I already have, there's just not enough of a gap to feed those two side mounted fans.
Click to expand...

I don't think you did try it, to be honest.

a quarter inch made a ton of difference on my cards, no reason to assume it wouldn't do the same for you.

just my opinion, doesn't matter in the long run.
 
stealthy123 said:
I don't think you did try it, to be honest.

a quarter inch made a ton of difference on my cards, no reason to assume it wouldn't do the same for you.

just my opinion, doesn't matter in the long run.
Click to expand...

Whatever man, now you're just trying to troll. It's refreshing to see how helpful the [H] community is nowadays. :)

I'm not an asshat, I understand cooling concepts. This was my bonus room about a year ago...

rigs1.jpg


rigs2.jpg
 
stealthy123 said:
I run crossfired 6850s in my main rig, and fyi, they have pencil erasers spacing them out, because until I did that I wasn't comfortable with the temps.

but ya, it's not a solution, it's a ridiculous idea that has no factual or experiential basis.
Click to expand...

And I used to have two 6950's Crossfired in this exact same machine, in the first two x16 slots without a problem even when they were running 100% load. It's the fan configuration and size of the fan shroud on these specific cards that's the problem. Hence why I'm trying to find a way to get those cards in the 1st and 3rd slot. I was hoping that someone might know if a longer crossfire bridge exists, but all I'm getting is, "You're not doing it/doing it wrong."

Yeesh :)
 
OP, I just spent the last 20 minutes or so google-fu'ing without luck on finding any people with anything longer than a 100mm bridge offhand for purchase :(, if I come up with anything I'll post here of course.

EDIT: Supposedly people were able to get Asus Australia to ship them one for around $15 item price + shipping a couple of years back... might be a lead to try calling their tech support center there or emailing them, to see if you can buy it. Your part# of 14G030025906 is what seems to be correct.

Phone for them appears to be: 1300 278 788
 
Last edited:
GoldenTiger said:
OP, I just spent the last 20 minutes or so google-fu'ing without luck on finding any people with anything longer than a 100mm bridge offhand for purchase :(, if I come up with anything I'll post here of course.

EDIT: Supposedly people were able to get Asus Australia to ship them one for around $15 item price + shipping a couple of years back... might be a lead to try calling their tech support center there or emailing them, to see if you can buy it. Your part# of 14G030025906 is what seems to be correct.

Phone for them appears to be: 1300 278 788
Click to expand...

Thanks GT :) I'm trying to work that route now, but it looks like that's the only real option.
 
Oh boy an AMD thread, time to pounce for the attack.
 
Last edited:
MeatballCB said:
Whatever man, now you're just trying to troll. It's refreshing to see how helpful the [H] community is nowadays. :)

I'm not an asshat, I understand cooling concepts. This was my bonus room about a year ago...

rigs1.jpg


rigs2.jpg
Click to expand...

Jesus dude. Nice boxen.
 
JDanser said:
Jesus dude. Nice boxen.
Click to expand...

Ah, thanks :) That was about 3/4 of a 11 GH Bitcoin mining farm I had running last year. Started getting sick of dealing with the heat/noise and dealing with it all, so sold off most of it and just have a few cards still going.

Was fun to mess around with though and ended up making a few bucks when it was all said and done.
 
GoldenTiger said:
OP, I just spent the last 20 minutes or so google-fu'ing without luck on finding any people with anything longer than a 100mm bridge offhand for purchase :(, if I come up with anything I'll post here of course.

EDIT: Supposedly people were able to get Asus Australia to ship them one for around $15 item price + shipping a couple of years back... might be a lead to try calling their tech support center there or emailing them, to see if you can buy it. Your part# of 14G030025906 is what seems to be correct.

Phone for them appears to be: 1300 278 788
Click to expand...

Unfortunately that number won't work, 1300 are internal to Australia only, I don't know what their international number is.

But if the number does route, it would be 011 61 1300 278 788

OP, I'll try and contact them tomorrow, and see if I can order one, I'll let you know.

Cheers
 
You can try calling them in the US at 510-791-3705 on M-F from 8 AM-5:30 PM PST and talk to them as well. I did, and after about 15 minutes of menus/holding, I finally got someone. The person I talked to was semi helpful. She said she was going to see if they could get one from the international side and would contact me again.

But I'm not holding my breath. She also claimed they only had a 3.3" and 3.6" version available when there's also a 3.9" version available on the US eStore. (Which I've ordered).
 
MeatballCB said:
You can try calling them in the US at 510-791-3705 on M-F from 8 AM-5:30 PM PST and talk to them as well. I did, and after about 15 minutes of menus/holding, I finally got someone. The person I talked to was semi helpful. She said she was going to see if they could get one from the international side and would contact me again.

But I'm not holding my breath. She also claimed they only had a 3.3" and 3.6" version available when there's also a 3.9" version available on the US eStore. (Which I've ordered).
Click to expand...

I'm in Australia :) I'm not sure if you still would like me to try Asus Australia, I ran out of time today, but I can try tomorrow, and see if I can find a longer xfire bridge for you.
 
Get two crossfire cables, cut off the ends and solder them together to extend the length.
 
Those 3.9" bridges arrived from Asus today and are still too short to span the 5 card widths. Definitely need something at least a half an inch or more to make it. Still haven't heard back from Asus on the 127mm international version.

As for cutting off the cables and soldering, I suck at soldering, so I'm not even going to attempt that :)
 
You must log in or register to reply here.
Back
Top