Sign-in / Sign-up
Your question
Solved

gtx 580 1.5gb and 3gb SLI vs. 1.5gb SLI or 3gb SLI - How much slower is a mix (1.5gb +3gb) going to be?

Tags:
  • gtx 580
  • SLI
  • Graphics
  • Gtx
  • difference in fps
  • Graphics Cards
  • mixed vram SLI
Last response: in Graphics Cards
October 11, 2013 8:34:32 AM

I currently have a evga gtx580 1.5gb, and have a chance to buy an extra card with the only difference being its 3gb. My questions are A) If running a 580 1.5gb with a 3gb in SLI is not as effective as 1.5gb SLI or 3gb SLI, how much slower are the mixed cards in SLI going to be compared to the matched cards in SLI? .. And B) would it be smarter to just buy a single gtx 780 and get rid of the 580.
I looked everywhere but couldn't find an answer, Ideally I would like to see a fps comparison between the mixed SLI (1.5gb with a 3gb) and the matched SLI's (either 1.5gb SLI or 3gb SLI). But any opinion would be appreciated. I don't know much about SLI's but ive heard they can cause other problems compared to running single cards?

....So basically HOW MUCH SLOWER is running a mixed vram 580 sli compared to same size vram SLI?
thank you for any answers.
(first time question, sorry if its a bit confusing)

ALSO
If anyone has actually run a 1.5 and a 3gb together please let me know what happened, speed and compatibility wise.

More about : gtx 580 5gb 3gb sli 5gb sli 3gb sli slower mix 5gb 3gb

a c 137 U Graphics card
October 11, 2013 8:38:27 AM

Nvidia doesn't generally play well with different RAM sizes on the cards. There used to be a coolbits solution that would let you pair cards with different RAM sizes and work at the lowest common denominator, but that's not been supported for years.
m
0
l
October 11, 2013 8:44:32 AM

ubercake said:
Nvidia doesn't generally play well with different RAM sizes on the cards.....

.
are you saying that it wont work? or that it would cause lots of problems? just so I know, theoretically if you did run a 1.5 and a 3gb would it be a lot slower than 2 of the same? But yeah I get your basically saying don't do it.

m
0
l
Related resources
October 11, 2013 8:47:01 AM

If anyone has actually run a 1.5 and a 3gb together please let me know what happened, speed and compatibility wise. AND Thanks for your answer ubercake.
m
0
l
October 11, 2013 8:52:54 AM

In the chance that both cards paired up and SLI worked, you would loose 1.5GB from the 3GB card. The RAM from the smaller card will ALWAYS determine what the total RAM is available. It would never average out. So in theory if both card paired and worked with a 1.5GB memory buffer, the only time you would be limited in performance is when gaming at very high resolutions whereby the frame buffer of that resolution exceeded the storage capacity of your total RAM (1.5GB). At regular resolutions (1920x1080) for example your games will perform very well with no performance issues and the full benefits of SLI.
m
0
l

Best solution

a c 137 U Graphics card
October 11, 2013 8:54:32 AM

There's more info on this on the SLI FAQ at geforce.com:
http://www.geforce.com/hardware/technology/sli/faq#c19

They actually removed this bit of information from the geforce site for a while and I see that it's back about using the different memory sizes. You should wait to see what other people have to say, but my recommendation would be to not try something like this. Nvidia doesn't recommend using different memory sizes even while telling you about their coolbits tool that allows you to use cards with different memory sizes.

With multi-card setups, there's a delicate balance to be maintained. While SLI has been trouble-free for me, I personally wouldn't do anything outside the Nvidia recommended guidelines or your experience with SLI may be tainted altogether.
Share