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
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
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