GTX 580 SLI question

[sniper2606]

Morning people first of all my condolences goes to the people of Japan.

I was just wondering if i be able to run a GTX 580 SLI setup with out bottlenecking the cpu with my current rig, i know i dont have the most powerful setup but i can always OC the cpu especially with this amazing MOBO with a single push of a button it will OC automatically

My Setup:

XFX Black Edition XPS-850W
i7-950 Bloomfield 3.06GHz
CORSAIR XMS3 4GB
MSI Big Bang-XPower
500GB 7200 RPM 32MB SATA 6.0Gb
1 GTX 580 EVGA
Windows 7 home premium 64bit

 

[55Range]

You should be absolutely fine with these specs. Go ahead.
Yes a little oc on the cpu might be needed but easily done.

 

[sniper2606]

ok cool, i was just a lil worry on the power supply note its only 850w, i though i might needed something stronger

 

[55Range]

Yeah that might be necessary especially if you plan on oc. a 900 w should be enough, Look for a 1000w psu for optimum oc margin/perf

 

[17seconds]

You will be good with that power supply and setup. Note that it is almost impossible not to bottleneck a pair of GTX 580's with just about any setup. Luckily, your setup is high-end, and the more you overclock your processor, the more performance you will get out of your GPU's. As reference, Guru3d had 1.58x scaling with GTX 580's on a Core i7 system overclocked to 3.65 ghz and 1.70x scaling with a pair of GTX 570's on the same system. An even faster system would improve the scaling even more, but those are still pretty good numbers over a variety of benchmarks. Basically, as you see below, scaling decreases as you increase the performance level of the GPU.

http://www.guru3d.com/article/radeon-hd-6950-crossfirex-review/
http://www.guru3d.com/article/geforce-gtx-560-ti-sli-review/
http://www.guru3d.com/article/geforce-gtx-570-sli-review/
http://www.guru3d.com/article/geforce-gtx-580-sli-review/
http://www.guru3d.com/article/asus-gtx580-directcu-ii-sli-review/

Average dual card scaling across all benchmarks at 1920x1200:
6950: 1.67x
560: 1.69x
570: 1.7x
580: 1.58x
Asus 580: 1.51x

Noise levels (vs. single card)
6950: 49 Dba (+8 Dba)
560: 40 Dba (+3 Dba)
570: 42 Dba (+2 Dba)
580: 46 Dba (+5 Dba)
Asus 580: 42 Dba (+3 Dba)

GPU Temps (vs. single card)
6950: 89c (+12c)
560: 74c (+6c)
570: 81c (+4c)
580: 90c (+3c)
Asus 580: 73c (+7c)

 

[geekapproved]

Your going to need a huge overclock to keep up with those cards. I mean well over 4ghz.

 

[ubercake]

I don't OC. My system (see my signature) hits 750W-ish measured with an appliance load tester when playing Medal of Honor. Both GPUs in GPU-z are hitting 100% load at times during game play with maximum details/AA/AF, etc...

You have more than enough amps on the 12V rail (70A) and watts on your current power supply to run two 580s at stock speeds.

OC at your own risk.

 

[17seconds]

A good power supply like he has can sustain more than its rated power, anyway, so I wouldn't automatically assume the PSU can't handle it. Those Guru3d articles say you need a minimum 800+ watt PSU for an average system (more for overclocking).

They put out 604 system watts under full stress on this system:
"Our test system is based on a power hungry Core i7 965 / X58 system. This setup is overclocked to 3.75 GHz. Next to that we have energy saving functions disabled for this motherboard and processor (to ensure consistent benchmark results). On average we are using roughly 50 to 100 Watts more than a standard PC due to higher CPU clock settings, water-cooling, additional cold cathode lights etc."

 

[sniper2606]

nice good to know i have a decent rig, i wonder how i can disable the energy saving on the mobo sounds like i could use that

 

[17seconds]

nice good to know i have a decent rig, i wonder how i can disable the energy saving on the mobo sounds like i could use that

That would be a BIOS option. I wouldn't do it straight away. Try out the system first, then see where you need to do some tweaking. Fun times!

Oh yeah, we're both running MSI mobos. It's under "Green Power" in the BIOS. It can be set to Auto or Disabled.

 

[sniper2606]

yeah especially with new parts i just order this parts monday, putting it together monday gotta break in it i guess.

MSI FTW! hmm green power..... everything is green these day... lol anyways big help thanks

 

[sniper2606]

i might wait till the GTX price lowers a bit too

 

[ubercake]

You should be absolutely fine with these specs. Go ahead.
Yes a little oc on the cpu might be needed but easily done.

Something to consider when looking at how they OC the processors during video card benchmarks:

The people doing the benchmarks want to show you in every which way the performance of the video cards alone. By OCing the processors, they take the processor out of the equation. They can compare apples to apples with different graphics cards at that point. They don't have to explain the fact that because they are using a quad-core 6600 there was a bottleneck affecting video performance so we really can't accurately tell what kind of framerates you'll get. This is why they OC the crap out of the CPU for reviews. So, because they do doesn't mean you have to in order to get comparable performance.

One of the tests to see if your CPU bottlenecks your GPUs is to look at the GPU load in GPUz. If your GPUs are consistently hanging out with low loads in graphics intensive titles (and you CPU is working overtime) and you are getting less than desirable performance, you have yourself a bottleneck caused by the CPU.

My video cards would not be hitting the 100% mark in BFBC2 or Medal of Honor if they were being bottlenecked. Some games rely heavily on CPU for things on many game engines that haven't been optimized for the GPUs - where many times the processing should have been coded to be passed off to the video cards. These are the times when you consider the OC. I have not reached this point with my i7-930. On the other hand, I haven't touched Metro 2033.

 

[17seconds]

You can also see how well a CPU and GPU pair up by running 3D Mark 11 or Vantage. The final score is divided into GPU score and overall score. The closer these two scores match, the more closely paired are your components.

 

[sniper2606]

You can also see how well a CPU and GPU pair up by running 3D Mark 11 or Vantage. The final score is divided into GPU score and overall score. The closer these two scores match, the more closely paired are your components.

My current overall score on 3dmark 11 with a single gtx 580 is 6650, im getting the second gtx 580 tuesday, i will run SLI and post the results.

PS, I now have 12gm memory ram and OC cpu to 3.7 with Crucial M4 256gb SSD, Had to update some things