Overclock.net › Forums › Graphics Cards › NVIDIA › SLI running 16x/8x, performance loss?
New Posts  All Forums:Forum Nav:

SLI running 16x/8x, performance loss?

post #1 of 6
Thread Starter 
ok, say I have 2 9800GX2's and I am running them on a MSI 750i mb. Which makes it run at 16x for one pci-e and 8x for the other pci-e. Would I see an improvement going up to a 780i mb so I can have 2 pci-e 16x slots?


Just wanting some opinions on this, as a buddy of mine asked and to be honest wasn't sure what to say. He was thinking of going core i7 but all he does is game and he is running an E8400 oc'ed.

So what do you SLi buffs say, would he be better off and see a bigger performance gain going core i7 with an X58 mb or would a 780i be alright.
Edited by rx7racer - 12/15/08 at 6:05pm
D
(15 items)
 
The Sheep Skinner
(13 items)
 
 
CPUMotherboardGraphicsRAM
Intel i7 6700 Gigabyte Z170N-Gaming5 Sapphire Radeon R9 Fury Tri-X 3840 G.Skill TridentZ  
Hard DriveCoolingCoolingCooling
960 EVO 500GB EK SE 240mm, Magicool slim 240mm EK Supreme HF CU Gold EKFC-Fury X WB 
OSMonitorPowerCase
Win 10 Pro Acer XG270HU EVGA 750W  Evolv ITX 
MouseMouse Pad
Naos7000 Corsair MM600 
CPUMotherboardGraphicsRAM
C2D E8400 DFI LT P35 Radeon HD4890 OCZ 2GB 800MHz 
Hard DriveOptical DriveOSMonitor
500GB Asus multi DVD W7 U Samsung 2232BW+ 
PowerCase
Corsair HX520W CM 690 
  hide details  
Reply
D
(15 items)
 
The Sheep Skinner
(13 items)
 
 
CPUMotherboardGraphicsRAM
Intel i7 6700 Gigabyte Z170N-Gaming5 Sapphire Radeon R9 Fury Tri-X 3840 G.Skill TridentZ  
Hard DriveCoolingCoolingCooling
960 EVO 500GB EK SE 240mm, Magicool slim 240mm EK Supreme HF CU Gold EKFC-Fury X WB 
OSMonitorPowerCase
Win 10 Pro Acer XG270HU EVGA 750W  Evolv ITX 
MouseMouse Pad
Naos7000 Corsair MM600 
CPUMotherboardGraphicsRAM
C2D E8400 DFI LT P35 Radeon HD4890 OCZ 2GB 800MHz 
Hard DriveOptical DriveOSMonitor
500GB Asus multi DVD W7 U Samsung 2232BW+ 
PowerCase
Corsair HX520W CM 690 
  hide details  
Reply
post #2 of 6
I think he'll see a slight improvement, but IMO it's not worth the cost of a new mobo.
Space Heater
(13 items)
 
  
CPUMotherboardGraphicsRAM
Xeon W3520 Foxconn Bloodrage Sapphire 4890 Toxic 12GB Corsair DDR3 1333mhz 
Hard DriveOptical DriveOSMonitor
Vertex 2 60GB|4.5TB Storage A POS LG one.. Windows 7 Ultimate x64 Samsung Syncmaster 2443BWX 
KeyboardPowerCaseMouse
Logitech G15 v2 PC Power & Cooling 750w Antec 1200 Logitech G5 
Mouse Pad
A POS BestBuy one.. 
  hide details  
Reply
Space Heater
(13 items)
 
  
CPUMotherboardGraphicsRAM
Xeon W3520 Foxconn Bloodrage Sapphire 4890 Toxic 12GB Corsair DDR3 1333mhz 
Hard DriveOptical DriveOSMonitor
Vertex 2 60GB|4.5TB Storage A POS LG one.. Windows 7 Ultimate x64 Samsung Syncmaster 2443BWX 
KeyboardPowerCaseMouse
Logitech G15 v2 PC Power & Cooling 750w Antec 1200 Logitech G5 
Mouse Pad
A POS BestBuy one.. 
  hide details  
Reply
post #3 of 6
Quote:
Originally Posted by rx7racer View Post
ok, say I have 2 9800GX2's and I am running them on a MSI 750i mb. Which makes it run at 16x for one pci-e and 8x for the other pci-e. Would I see an improvement going up to a 780i mb so I can have 2 pci-e 16x slots?


Just wanting some opinions on this, as a buddy of mine asked and to be honest wasn't sure what to say. He was thinking of going core i7 but all he does is game and he is running an E8400 oc'ed.

So what do you SLi buffs say, would he be better off and see a bigger performance gain going core i7 with an X58 mb or would a 780i be alright.
No. Your 9800GX2's will simply sit around more waiting for the shader portions of the graphics cards to get finished doing their job. 90 percent of dx 10 games are shader limited not bandwidth limited. So you just have to wait until video card manufactures come out with cards that have processors the size of 486 chips before DX10 stuff gets faster. When they say enables 2.8 times performance increase it's making big assumptions that this depression we are heading into is not going to barbeque half the corporations on the planet. And they are actually able to spend months and years putting more and more shaders on chips and suddenly be bandwidth limited again without necessitating changing to a small nuclear power plant instead of power supplies. Running 3 full length pci-express cards with 3 fans each, rewiring a circuit in your house to 30 amps so you can plug a 1400 watt power supply into it without burning down your house. All so phsyx and sli can be cool. I just don't see that working out for very many people. Especially when one of those cards is so stuffed with shader transistors that using it to physx and taking 200 watts to do it will make any sense at all. I might be being a bit pessimistic but I just don't have alot of hope that we can transition to desktop supercomputers during an economic depression so metal gear solid 5 will rock hard in 2012. I've never constructed a utopian computer society before but I don't think this formula is going to work.
Edited by Hephasteus - 12/15/08 at 7:04pm
Goofy
(13 items)
 
  
CPUMotherboardGraphicsRAM
AMD 4850e 2.4Ghz 22 watts 1.1v 1500HT 300FSB Gigabyte GA-M78SM-S2H What I'm Testing 2 2gb Geil PC6400 960MHZ 
Hard DriveOptical DriveOSMonitor
Hitachi 160gb SATA-II Pioneer DVR 111D Redhat Core 12 x86_64, Windows XP HANNspree 20" 1600x900 
KeyboardPowerCaseMouse
Logitec Premium Desktop Mini-Box M3-ATX 120 Watt DC-DC Spire Logitec 
Mouse Pad
Xtrac 
  hide details  
Reply
Goofy
(13 items)
 
  
CPUMotherboardGraphicsRAM
AMD 4850e 2.4Ghz 22 watts 1.1v 1500HT 300FSB Gigabyte GA-M78SM-S2H What I'm Testing 2 2gb Geil PC6400 960MHZ 
Hard DriveOptical DriveOSMonitor
Hitachi 160gb SATA-II Pioneer DVR 111D Redhat Core 12 x86_64, Windows XP HANNspree 20" 1600x900 
KeyboardPowerCaseMouse
Logitec Premium Desktop Mini-Box M3-ATX 120 Watt DC-DC Spire Logitec 
Mouse Pad
Xtrac 
  hide details  
Reply
post #4 of 6
It's not going to give more than about a 5% performance increase, if that. I wouldn't do it personally. As Hephasteus said, x16 x16 just doesn't deliver noticeably better performance than x16 x8.
Unbuilt
(13 items)
 
  
CPUMotherboardGraphicsRAM
Core 2 Duo E4600 Asus P5Q Pro **Ordered** EVGA e-GeForce 8600GTS SSC 256MB 2GB Corsair DDR2 800 
Hard DriveOptical DriveOSMonitor
Western Digital 200GB (IDE) none Windows Server 2008 Standard Workstation 2xCTX X571A 
PowerCase
PowerUp! 800 (free, hopefully Corsair or OCZ soon) Antec 300 
  hide details  
Reply
Unbuilt
(13 items)
 
  
CPUMotherboardGraphicsRAM
Core 2 Duo E4600 Asus P5Q Pro **Ordered** EVGA e-GeForce 8600GTS SSC 256MB 2GB Corsair DDR2 800 
Hard DriveOptical DriveOSMonitor
Western Digital 200GB (IDE) none Windows Server 2008 Standard Workstation 2xCTX X571A 
PowerCase
PowerUp! 800 (free, hopefully Corsair or OCZ soon) Antec 300 
  hide details  
Reply
post #5 of 6
Thread Starter 
Alright guys, thanks for the info. So I guess he should go core i7 then.

I just knew from my experience with CF that having a 16x and 8x bus hurt performance pretty bad so I assumed the same for SLI but apparently SLI isn't as bandwidth intensive as CF.

+rep to all.
D
(15 items)
 
The Sheep Skinner
(13 items)
 
 
CPUMotherboardGraphicsRAM
Intel i7 6700 Gigabyte Z170N-Gaming5 Sapphire Radeon R9 Fury Tri-X 3840 G.Skill TridentZ  
Hard DriveCoolingCoolingCooling
960 EVO 500GB EK SE 240mm, Magicool slim 240mm EK Supreme HF CU Gold EKFC-Fury X WB 
OSMonitorPowerCase
Win 10 Pro Acer XG270HU EVGA 750W  Evolv ITX 
MouseMouse Pad
Naos7000 Corsair MM600 
CPUMotherboardGraphicsRAM
C2D E8400 DFI LT P35 Radeon HD4890 OCZ 2GB 800MHz 
Hard DriveOptical DriveOSMonitor
500GB Asus multi DVD W7 U Samsung 2232BW+ 
PowerCase
Corsair HX520W CM 690 
  hide details  
Reply
D
(15 items)
 
The Sheep Skinner
(13 items)
 
 
CPUMotherboardGraphicsRAM
Intel i7 6700 Gigabyte Z170N-Gaming5 Sapphire Radeon R9 Fury Tri-X 3840 G.Skill TridentZ  
Hard DriveCoolingCoolingCooling
960 EVO 500GB EK SE 240mm, Magicool slim 240mm EK Supreme HF CU Gold EKFC-Fury X WB 
OSMonitorPowerCase
Win 10 Pro Acer XG270HU EVGA 750W  Evolv ITX 
MouseMouse Pad
Naos7000 Corsair MM600 
CPUMotherboardGraphicsRAM
C2D E8400 DFI LT P35 Radeon HD4890 OCZ 2GB 800MHz 
Hard DriveOptical DriveOSMonitor
500GB Asus multi DVD W7 U Samsung 2232BW+ 
PowerCase
Corsair HX520W CM 690 
  hide details  
Reply
post #6 of 6
I have a related question. I'm running two 7900gs cards on an Asus An2-E Sli motherboard which has both boards at 8x, if I'm reading the specs right. I'm upgrading to an Asus M3A79-t Deluxe which has the advantage of being able to run 2 at 16x or 3 or 4 cards at 8x. Would it be better to have three at 8x or two at 16x?
    
CPUMotherboardGraphicsRAM
AMD FX-62 ASUS M2NE SLI EVGA GTX 260 CORE 216 4gb Transcend AxeRam 
Hard DriveOptical DriveOSMonitor
2 160gb WD RAID Samsung DVD Vista Home Premium 64 Samsung Syncmaster 2232GW 
KeyboardPowerCaseMouse
Razer Tarantula 750 Watt Corsair Antec based custom Razer Copperhead 
  hide details  
Reply
    
CPUMotherboardGraphicsRAM
AMD FX-62 ASUS M2NE SLI EVGA GTX 260 CORE 216 4gb Transcend AxeRam 
Hard DriveOptical DriveOSMonitor
2 160gb WD RAID Samsung DVD Vista Home Premium 64 Samsung Syncmaster 2232GW 
KeyboardPowerCaseMouse
Razer Tarantula 750 Watt Corsair Antec based custom Razer Copperhead 
  hide details  
Reply
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: NVIDIA
Overclock.net › Forums › Graphics Cards › NVIDIA › SLI running 16x/8x, performance loss?