Can a GTX 770 4GB w/ SLI utilize the 4GB of VRAM?

TheGroobster

Reputable
Apr 7, 2014
12
0
4,510
I just read a post saying a single GTX 770 could [strike]only utilize up to 2.2GB of VRAM[/strike] has a max effective usage limit of 2.2GB because of the 256-Bit memory bus. So I have been looking at purchasing one of these to eventually use SLI. Can anyone confirm that this card will be able to effectively utilize more of that VRAM when it is in SLI? Otherwise there is no point for me to buy that card.

EDIT: Misquoted the original post
 
Solution


It is all based on resolution and computing power but here is the proof in favor of the 4GB card...

TheGroobster

Reputable
Apr 7, 2014
12
0
4,510
Sorry, I did not word that correctly. The correct wording is "the GTX 770's effective usage limit is 2.2GB". So my question is actually "will the GTX 770 4GB use the VRAM more efficiently in SLI?".
 

apcs13

Honorable
Oct 2, 2013
960
0
11,360
Could've been me that you saw, I just wrote something similar on another user's forum. If it was me, then well you know what I said. If not, well then yes I can tell you that the 256 bit memory bus on the GTX 770 unfortunately hurts the amount of VRAM the GTX 770 can utilize. If you already have a 770 4GB, it might be okay to run a SLI config, but otherwise I would not recommend it, I have a 770 2GB myself but it is not worth it for SLI. Instead of getting SLI, go for a 780 or 780 TI.
 

apcs13

Honorable
Oct 2, 2013
960
0
11,360


I actually have to disagree with you. The 2GB 770 and 4GB 770 perform almost exactly the same, even at resolutions such as 2560x1440 and other high resolutions. This is because the GTX 770 is limited by the 256-bit memory bus that it is equipped with. Just take a look at this webpage: http://alienbabeltech.com/main/gtx-770-4gb-vs-2gb-tested/3/

I debated this myself when I bought my 770, but even in SLI conditions the 4GB isn't really used.
 

Fokissed

Distinguished
Feb 10, 2010
392
0
18,810
A 256 bit bus doesn't suffer from a portion of slow VRAM. A 256 bit bus needs 1, 2, or 4 GB of VRAM while a 384 bit bus needs .75, 1.5, or 3 GB of VRAM. anything else will have a slow (reduced bandwidth) portion of VRAM.
 


How's that? Assuming VRAM works similar to ordinary RAM, it's not possible to say for sure unless we know how many address bits are there(32 will be needed for 4 GB).
 

TheGroobster

Reputable
Apr 7, 2014
12
0
4,510
@apcs13, yeah I think it might have been your post that I read. I didn't want to hijack the thread so decided to ask it here. And yes I was looking at getting the 770 4GB version so in a couple years I could SLI them and get a new monitor that will support > 1080p resolutions. Because I can't really justify the price jump for 2GB of RAM that won't really be used.

EDIT: Ok now I see some other posts that are saying the 256-bit bus will efficiently utilize 4GB of VRAM so maybe it is not a bad idea
 

apcs13

Honorable
Oct 2, 2013
960
0
11,360


Every thread I have seen has shown the 4GB option either being 1 frame per second better than the 2GB at best, or the same performance for a lot more money. Just look at the included bench-marking website I included, heck, google one to find another yourself. You can clearly see that even at low, medium, high, and very high resolutions, the performance of the 4GB 770 is never more than 2FPS better than the 2GB card. If you think spending $40-$100 for an extra 2FPS at best is worth it, then by all means, go ahead and purchase the 4GB model. I think that you would be much better of getting a 780 or 780 Ti now and not spending more on another 770 later, so you have more effective memory to use. The 780 is a decent deal better than the 770 and the 780 Ti even more so.
 

apcs13

Honorable
Oct 2, 2013
960
0
11,360


Well that assumption is off, VRAM is completely independent from RAM and the operating system. Just look at other threads and benchmarks like the one I linked a few posts ago, you can see the extra 2GB VRAM doesn't help any more than a value that could be considered in the margin of error.
 

apcs13

Honorable
Oct 2, 2013
960
0
11,360


That's more of a compatibility issue, and I never mentioned the speed of the video memory, I was talking about the effectiveness of it and what amount of bandwidth will actually be used.

A larger memory bus DOES have a profound effect on the memory bandwith of a graphics processing unit, otherwise it wouldn't make sense to have anything higher than 128-bit or 256-bit memory buses, yet you see R9 290's and 290X's, as well as GTX 690s (just to name a few) with 512-bit buses. The simple truth is that higher amounts of video memory require larger memory buses to be fully utilized. Just take a look at any benchmarks, wether it be the one I linked or another on the world wide web, it is conclusive that at a whole bunch of different high resolutions, the 4GB edition of the 770 outperforms the 2GB very inconsistently, and when it does, it is usually 0.1-2FPS. In my opinion, that is nowhere worth spending an extra $40-$100, which could be used towards a better GPU or processor etc., but if that is what you really really want, I guess go ahead. I would highly advise against it though.
 

TheGroobster

Reputable
Apr 7, 2014
12
0
4,510


I apologize. Maybe you misunderstood. For now I would pay the extra $40-$100 on the 4GB version and then later on I would get another and SLI them with a higher resolution monitor. Don't you need more VRAM for high resolutions?

 

apcs13

Honorable
Oct 2, 2013
960
0
11,360


Yes, but as you can clearly see from any benchmark including the one I already provided ( http://alienbabeltech.com/main/gtx-770-4gb-vs-2gb-tested/3/ in case you need to see again), the extra 2GB doesn't even do anything because of that limiting 256-bit memory bus, which DOES actually have a large impact on the memory's utilization. Even at high resolutions, the 4GB GTX 770 only performs 0-2 FPS better than the 2GB version, and that is very much within the margin of error. In fact, in some tests, the 2GB card outperforms the 4GB card! What this tells you is that even at high resolutions the extra memory does nothing really, so it is basically like comparing two identical cards, which is why the numbers are so very close to each other.

Again, I would really recommend instead of spending $600-900 over 2-4 years in two GTX 770's, spend $500 right now for the $780 or $650-$700 for the 780 Ti and get better performance. Depending on price fluctuations, you could even end up getting an SLI 780 config for only a little more than a 770 SLI config in the future!
 

TheGroobster

Reputable
Apr 7, 2014
12
0
4,510
@apcs13 Ah I think I finally get it now. I apologize for being a bit slow on the uptake. Basically they are the same card except for the extra 2GB of ram. So while the extra VRAM might give you some leeway in terms of resolutions it's not going to affect the fps. Unless I am wrong, if you try and use a 2GB card with Metro Last Light a 1440p resolution + AA it is not going to handle it properly(assuming the bus isn't holding you back). But as far as the GPU clock is concerned, you aren't getting a better framerate all things being equal there. So (assuming there is no limitations in the memory bus), the same GPU clock + 2 extra GB of memory does not = better fps but it will be able to handle higher resolutions from a memory standpoint(not an fps standpoint).

Anyways, I think you are right. Unless I go with a single 2GB 770 its probably not with it. The price is actually pretty affordable for the performance IMHO. It's going to be an agonizing decision. ;-)
 


It is all based on resolution and computing power but here is the proof in favor of the 4GB card http://www.hardwarecanucks.com/forum/hardware-canucks-reviews/65636-pny-gtx-770-oc2-4gb-review-6.html whether this is actually acceptable frame rates is another story but would be if you had 2 x in SLI!
 
Solution

JUICEhunter

Honorable
Oct 23, 2013
1,391
0
11,960
Not very many in-depth 4gb vs. 2gb SLI articles out there. Found a good 670 4gb vs. 2gb review which should apply to the 770 as they even have a few charts vs. a 2gb 680 SLI:

http://www.hardocp.com/article/2013/01/14/asus_geforce_gtx_670_directcu_ii_4gb_sli_review/2#.U0Oe3TpOWNY

Notice Far Cry 3 which was the first game that made my old 670 cry has much better min fps on the 4gb vs. 2gb SLI the older games do show very little difference though to argue everyone else's point. 780ti is the way to go especially since it's been going on sale a lot lately.
 

FunSurfer

Distinguished
2GB cards may not be enough in the near future even at 1080p because of the "Next gen console effect", as seen in the first example released few months ago: Call of Duty Ghosts, which needs 5GB(!!!) of VRAM to play smoothly. May be 'memory leak' or not, no patch/fix was released so we are going to be stuck with that console optimization.
 

TheGroobster

Reputable
Apr 7, 2014
12
0
4,510


Yes! That is why I want to pick up a 780 or 280X. However the price jump seems a tad unreasonable so I think I may wait a bit because I want to get a proper desk and computer. Right now my situation there is pretty horrible.

EDIT: Spelling
 

FunSurfer

Distinguished


Waiting for now is good, because the required near-future VRAM size will be much clearer when The Witcher 3 system requirements will be released.
 

gasolin

Distinguished
Aug 6, 2012
563
3
19,015


I Know it's an old thread, don't you think theres a difference between the 2 and 4gb gtx 770 in favor of the 4gb card because the 4gb card is oced ? 1112 vs 1254 mhz 2gb vs 4gb