Can two GTX 580s in PCIe x8 SLI be over-clocked, or are they out of bandwidth?

[GuruMeditationError]

I stumbled on a LinusTechTips video (added to the bottom of this post) while I was researching a question for my build.

 

The video shows that two GTX 580s in PCIe x8 SLI is just about at the maximum of what the PCIe x8 slots can handle (that moving the cards from PCIe x16 slots to PCIe x8 slots only reduce the performance of the two cards in SLI by 0.001%

 

I have two Gigabyte GTX 580 SOC's  that I need to run two slots apart in the x16 and x8 PCIe slots (so that I can cool them properly with a closed-loop cooler on one of them (because they run really hot)).

 

EDIT:

The Gigabyte GTX 580 SOC has a button on the underside of the card marked "Extreme" which if pressed, switches the card from the main Bios to "one that is tailored to work around the GF110’s cold bug when under [liquid nitrogen]"...

 

...who knew? 

 

And yes, it seems this button, somewhere along the line had gotten pressed.   :rolleyes:

 

 

My question is this: is it worth putting closed-loop coolers on both cards to over-clock them or is the PCIe x8 speed a bottleneck that invalidates whatever over-clocking might be possible? Basically is all the bandwidth already used up or is that not how it works?

 

https://www.youtube.com/watch?v=NFMzRZqFh-w

[FloRolf]

sure you can oc them.

 

But i'm not sure if watercooling such "old" cards is worth it. i mean a single 780 outperforms them.

[Shd0w2]

sure you can oc them.

 

But i'm not sure if watercooling such "old" cards is worth it. i mean a single 780 outperforms them.

yep lol... three 480's can't even match a 770. (We've come a LONG way)

[Tam3n]

8x mode doesn't hinder them at all.

[flibberdipper]

It will be a marginal bottleneck, if it even occurs.

[flibberdipper]

yep lol... three 480's can't even match a 770. (We've come a LONG way)

And the 480 had godly performance when it was introduced (as I remember).

[GuruMeditationError]

yep lol... three 480's can't even match a 770. (We've come a LONG way)

sure you can oc them.

 

But i'm not sure if watercooling such "old" cards is worth it. i mean a single 780 outperforms them.

 

Are you sure? So this isn't reliable?  :blink: http://www.videocardbenchmark.net/gpu.php?gpu=GeForce+GTX+770

 

I thought SLI would give me almost double the stock speed?  That's kind of what I based my purchase decision on.  :wacko:    

[Shd0w2]

Are you sure? So this isn't reliable?  :blink: http://www.videocardbenchmark.net/gpu.php?gpu=GeForce+GTX+770

 

I thought SLI would give me almost double the stock speed?  That's kind of what I based my purchase decision on.  :wacko:    

SLI can increase performance from 50% to 80% its really uncommon to see a 90%+ increase, due to sli optimization and such.

 

 

Edit: Or even in some games it can decrease performance, or it won't allow SLI. Plus, I meant to say the average is 50%-80% but sometimes it increases it by like a measly 20-40

[GuruMeditationError]

SLI can increase performance from 50% to 80% its really uncommon to see a 90%+ increase, due to sli optimization and such.

 

80% was actually what I was hoping for, also they're Gigabyte Super Overclocked each running 16% faster than stock, plus I was thinking of over-clocking them further. I know it varies from game to game but I'm going for the most cost-effective solution that'll get me onto the water-cooling / SLI upgrade curve.

 

Also, that 0.001% reduction doesn't indicate the bandwidth is all used up?

 

Edit: The 770 is only about 25% faster than a single standard 580.

[Shd0w2]

80% was actually what I was hoping for, also they're Gigabyte Super Overclocked each running 16% faster than stock, plus I was thinking of over-clocking them further. I know it varies from game to game but I'm going for the most cost-effective solution that'll get me onto the water-cooling / SLI upgrade curve.

 

Also, that 0.001% reduction doesn't indicate the bandwidth is all used up?

 

Edit: The 770 is only about 25% faster than a single standard 580.

Umm.... if you look at something: 3 480'S are up to par with a 680, a 770 is bascially a 680 with a couple exceptions... and I'm pretty sure that 3480's would equal two 580's. Keep in mind, Im talking about 3 overclocked 480'S watercooled.

[GuruMeditationError]

Umm.... if you look at something: 3 480'S are up to par with a 680, a 770 is bascially a 680 with a couple exceptions... and I'm pretty sure that 3480's would equal two 580's. Keep in mind, Im talking about 3 overclocked 480'S watercooled.

 

So I shouldn't pay attention to the benchmarks? 

 

http://www.guru3d.com/articles_pages/geforce_gtx_580_sli_review,9.html

 

http://www.videocardbenchmark.net/gpu.php?gpu=GeForce+GTX+770

 

:blink:  :wacko:  :unsure:

[Shd0w2]

So I shouldn't pay attention to the benchmarks? 

 

http://www.guru3d.com/articles_pages/geforce_gtx_580_sli_review,9.html

 

http://www.videocardbenchmark.net/gpu.php?gpu=GeForce+GTX+770

 

:blink:  :wacko:  :unsure:

First of all, your using two different sites which I presume are using different hardware (CPU, ram, etc) Which can make quite a difference given the CPU's.

[GuruMeditationError]

First of all, your using two different sites which I presume are using different hardware (CPU, ram, etc) Which can make quite a difference given the CPU's.

 

So what's the last word on it? Is there a definitive source for this kind of info? I just assumed these were a good rule of thumb.

[Recon-UK]

W ith the same scaling, 2 480's only need a core speed of 820mhz, and 4000 ddr. The 580 at the 480's 700mhz clock is a mere 4% faster.

[TheDigitalRealm]

To answer the question in your title, a 580 won't use up all the bandwidth in a PCI-e 3.0 8X slot. I'm pretty sure that a GTX 780 barely scrapes the limit of it. I think those GTX 580s were running at PCI-e 2. I speed. (if they were running on a Sandy Bridge then they'd be running at 2.0)

Yes, they can be over clocked. There won't be any limiting factors other than cooling.

[GuruMeditationError]

W ith the same scaling, 2 480's only need a core speed of 820mhz, and 4000 ddr. The 580 at the 480's 700mhz clock is a mere 4% faster.

 

Okay, so that's really confusing. What I'm hearing is: "If you run it slower it'll run slower". I don't really understand what the above really means?

 

Does that mean the 770 is so much more overclockable than the 580 SLI that overclocking a 770 is the best way to go?

 

It just seems the 770 is only about 25% faster than the 580 using the more favourable benchmarking software (i.e. the benchmarking software that shows two cards in SLI being almost twice the speed where real-world applications show less of an improvement).

 

To answer the question in your title, a 580 won't use up all the bandwidth in a PCI-e 3.0 8X slot. I'm pretty sure that a GTX 780 barely scrapes the limit of it. I think those GTX 580s were running at PCI-e 2. I speed. (if they were running on a Sandy Bridge then they'd be running at 2.0)

Yes, they can be over clocked. There won't be any limiting factors other than cooling.

 

Awesome, thanks so much. 

[Recon-UK]

Basically answering someone about 480 sli, given the same scaling, oc'd 480's easily match and even take the 580's crown, everything can be oc'd though.

[GuruMeditationError]

Basically answering someone about 480 sli, given the same scaling, oc'd 480's easily match and even take the 580's crown, everything can be oc'd though.

 

Okay, cool, that makes more sense, I thought you were answering the query about the 580s.  :blink:

[Recon-UK]

Anyone remember how poor the 480 did at crysis?

May want to feast your eyes onthis, back when i rocked 480's, this is just 1 at 850mhz core.

480 barely goes above 30fps in so called benchmarks...

[FloRolf]

@GuruMeditationError

 

FYI, heres a comparison i made between my 780 and a 590 (basically two 580s)

That should give you some idea of how the performance differs.

[Recon-UK]

590 is more like 2 570's, 2 580's are substantially faster.

[GuruMeditationError]

@FloRolf thanks, that's some interesting reading, also a bit confusing...

 

...videocardbenchmark.net rate the 590 as slower at running 3D Mark than the 580.  http://www.videocardbenchmark.net/gpu.php?gpu=GeForce+GTX+590

 

Is 3D Mark just not a realistic benchmark? I'm beginning to think I've based my purchase decisions on misinformation.  :unsure:

[FloRolf]

@FloRolf thanks, that's some interesting reading, also a bit confusing...

 

...videocardbenchmark.net rate the 590 as a slower at running 3D Mark than the 580.  http://www.videocardbenchmark.net/gpu.php?gpu=GeForce+GTX+590

 

Is 3D Mark just not a realistic benchmark? I'm beginning to think I've based my purchase decisions on misinformation.  :unsure:

 

i think videocardbenchmark.net is in generall a pretty weird website. I prefer my own benchmarks

But the 590 is definitely not slower than the 580 maybe they took the result per core or so...

[GuruMeditationError]

i think videocardbenchmark.net is in generall a pretty weird website. I prefer my own benchmarks

But the 590 is definitely not slower than the 580 maybe they took the result per core or so...

 

To be honest that confused me too. I just ended up assuming it was a card designed for a different market sector (like the Titans people are saying are purposed for industrial design) :0/

 

It might worth running searches for some more 590 benchmarks, I just don't really have the time right now...stuff to do