660ti 2gb essentially 1.5gb?

[AngleSlam]

So based on my experience I've never seen my 660ti ever use more than 1.5gb of ram.
I looked into it and realized that the 192 bit bus is a mismatch with 2gb ram. it has 3 64 bit controllers for 512mb then what happens to the lat 512mb?

It got me thinking about the gtx 670 how it is has 256 bit bus scales perfect with 2gb and has more bandwidth.

Anyways I only play on 1080p and I use msaa up to 4x. So far I haven't ran into any real lag in any of my games but for some reason I feel like I'm bottlenecking my cards full potential cuz it never goes past 1.5gb.
In practice I probably won't need more than 1.5gb but the card was advertised as 2gb and I feel disappointed.

 

[Durvelle27]

have you tried Skyrim maxed at 1080p with Mods

 

[AngleSlam]

Not yet but planning to..

 

[Durvelle27]

as i know for a fact that games uses more than 1.5GB of RAM when Maxed with MODs

 

[jimhsu]

I'm guessing it's a bandwidth bottleneck.

From the 660Ti review: http://www.anandtech.com/show/6159/the-geforce-gtx-660-ti-review/2

Of course at a low-level it’s more complex than that. In a symmetrical design with an equal amount of RAM on each controller it’s rather easy to interleave memory operations across all of the controllers, which maximizes performance of the memory subsystem as a whole. However complete interleaving requires that kind of a symmetrical design, which means it’s not quite suitable for use on NVIDIA’s asymmetrical memory designs. Instead NVIDIA must start playing tricks. And when tricks are involved, there’s always a downside.

The best case scenario is always going to be that the entire 192bit bus is in use by interleaving a memory operation across all 3 controllers, giving the card 144GB/sec of memory bandwidth (192bit * 6GHz / 8). But that can only be done at up to 1.5GB of memory; the final 512MB of memory is attached to a single memory controller. This invokes the worst case scenario, where only 1 64-bit memory controller is in use and thereby reducing memory bandwidth to a much more modest 48GB/sec.

How NVIDIA spreads out memory accesses will have a great deal of impact on when we hit these scenarios. In the past we’ve tried to divine how NVIDIA is accomplishing this, but even with the compute capability of CUDA memory appears to be too far abstracted for us to test any specific theories. And because NVIDIA is continuing to label the internal details of their memory bus a competitive advantage, they’re unwilling to share the details of its operation with us. Thus we’re largely dealing with a black box here, one where poking and prodding doesn’t produce much in the way of meaningful results.

As with the GTX 550 Ti, all we can really say at this time is that the performance we get in our benchmarks is the performance we get. Our best guess remains that NVIDIA is interleaving the lower 1.5GB of address while pushing the last 512MB of address space into the larger memory bank, but we don’t have any hard data to back it up. For most users this shouldn’t be a problem (especially since GK104 is so wishy-washy at compute), but it remains that there’s always a downside to an asymmetrical memory design. With any luck one day we’ll find that downside and be able to better understand the GTX 660 Ti’s performance in the process.

 

[rich_]

660 and 660ti are very over priced and very over-hyped. 7870's are beating the 660 AND 660ti in benchmarks that have taken place post-catalyst update starting late 2012. They are over-speccing and over-charging for a mid range 660ti, calling it a high end card.

 

[Ferzerp]

Memory is not used unless it is needed. If you've never seen over 1.5 Gb of use, you have not needed more than 1.5Gb of memory...

Having gobs of unused memory is not helpful, but running out is even worse.

 

[BallaTheFeared]

At 1080p for most titles 1GB is enough, for a select few 1.28GB is min, and for one or two 1.5GB is required for AA...

You aren't using more than 1.5GB because the games you're playing don't need more than that, there is nothing wrong with your card.

Performance wise your card is fine as well!

 

[BoFox]

Try Hitman: Absolution with MSAA, or Max Payne at high rez with MSAA, and see???

Did anybody ever prove if 660 Ti can actually use more than 1.5GB of VRAM? That'd be interesting!

 

[parvadomus]

Obviously the access to the last 512mb is much slower than the others, so its probably disabled at driver level for some games (marked as a memory hole), and enabled for the ones that really needs them. Well this is just one theory, anyways i never really liked 660TIs.

 

[notty22]

Try Hitman: Absolution with MSAA, or Max Payne at high rez with MSAA, and see???

Did anybody ever prove if 660 Ti can actually use more than 1.5GB of VRAM? That'd be interesting!

Nvidia uses this memory aproach on some pro- cards as well. Gtx 550ti, one model of the gtx 460se 1gb-192mb interface. It's named Asymmetrical memory technique, Ryan, or other reviewers can't explain it because Nvidia does not spell out how it works in Layman terms, it's a trade secret.
I believe there have been 3gb 660ti comparisons to 2gb 660ti versions, and they matched up.
It's been noted the 1gb 460's with 192mb interface used up to 1gb of Vram.


Crysis 3, results are as expected compared to gtx 670

 

[AngleSlam]

I did some research and from what I learned. The vram ram is only useful relative to the amount of horsepower a gpu can supply. The 660ti only has so much power by the time I'm maxing out at 2gb or even 1.5gb of vram the settings are probably too high anyways. So if I'm not mistaken I'm more likely to run into my gpu bottlenecking before vram bottlenecking.

 

[Keysplayr]

I did some research and from what I learned. The vram ram is only useful relative to the amount of horsepower a gpu can supply. The 660ti only has so much power by the time I'm maxing out at 2gb or even 1.5gb of vram the settings are probably too high anyways. So if I'm not mistaken I'm more likely to run into my gpu bottlenecking before vram bottlenecking.

Erm, then can you explain the GTX670? It has the same processing power as a 660Ti. Both are 1344 CUDA core parts. The GTX 660 is GK106 and has 960 CUDA cores and that has performance just under (sometimes over depending on game and settings) GTX 580 which is very similar to 7870 performance. 660Ti is generally faster than GTX 580 and 7870 usually falling right below 7950.

 

[amenx]

660 and 660ti are very over priced and very over-hyped. 7870's are beating the 660 AND 660ti in benchmarks that have taken place post-catalyst update starting late 2012. They are over-speccing and over-charging for a mid range 660ti, calling it a high end card.

See the charts above and tear your hair out.

 

[Keysplayr]

See the charts below and tear your hair out.

Yes, rich is quite incorrect. Overpriced? Maybe the 660Ti is at about 100 bucks over the 660. The 660 is probably one of the best cards for the money right now.
I got mine for 209.00 and there are some even less expensive right now. It reminds me of 8800GT or GTX 460 values.
I'm thinking of getting a second 660 for SLI.

 

[Keysplayr]

Normally, a 192-bit bus would take an odd amount of memory like 384MB, 768MB, 1.5GB. But Nvidia uses double density chips on the 3rd (I think) 64 bit memory register essentially bumping up the memory amount up another 512MB. It's a trick they've been using since the GTX550Ti I believe with 1GB of RAM on a 192-bit bus instead of 768MB. Upping it an additional 256MB.

So, what I can see happening on that "3rd" register is it takes twice as long at it's current transfer rate to fill the memory there as it is essentially twice as "deep" so to speak. Unless the memory controller runs that register at twice the clock of the other two 64 bit registers, it has no choice but to take longer to fill. Physics.

 

[Ferzerp]

You replied to a spammer trying to up a google search rank. Edit out his spam image link so when the mod deletes the post and bans the account it won't still be there?

 

[Keysplayr]

You replied to a spammer trying to up a google search rank. Edit out his spam image link so when the mod deletes the post and bans the account it won't still be there?

Wow, didn't even realize. Thanks Ferzerp. :thumbsup:

 

[BoFox]

Nvidia uses this memory aproach on some pro- cards as well. Gtx 550ti, one model of the gtx 460se 1gb-192mb interface. It's named Asymmetrical memory technique, Ryan, or other reviewers can't explain it because Nvidia does not spell out how it works in Layman terms, it's a trade secret.
I believe there have been 3gb 660ti comparisons to 2gb 660ti versions, and they matched up.
It's been noted the 1gb 460's with 192mb interface used up to 1gb of Vram.


Crysis 3, results are as expected compared to gtx 670

Would the 2560x1600 result with 4x SMAA actually use more than 1.5GB of RAM, or does it need to be MSAA or at least 8x SMAA?

Yeah, regarding GTX 550 Ti - I tried to point out all the problems I could find with it:
http://alienbabeltech.com/abt/viewtopic.php?f=4&t=27042&p=79775&hilit=gtx+550+ti+gts+450#p79775

Nvidia did it a little bit different with GTX 660 Ti, by not using different-density RAM chips.

http://www.anandtech.com/show/6159/the-geforce-gtx-660-ti-review/2
Still,

The best case scenario is always going to be that the entire 192bit bus is in use by interleaving a memory operation across all 3 controllers, giving the card 144GB/sec of memory bandwidth (192bit * 6GHz / 8). But that can only be done at up to 1.5GB of memory; the final 512MB of memory is attached to a single memory controller. This invokes the worst case scenario, where only 1 64-bit memory controller is in use and thereby reducing memory bandwidth to a much more modest 48GB/sec.

Perhaps that's why we haven't really seen anything.. YET. Like it took almost 1 year for us to see any problems with GTX 550 Ti (despite Deus Ex:HR using less than 500MB VRAM, which was strange), but I think NV did a better job with GTX 660 Ti this time.

 

[BoFox]

Erm, then can you explain the GTX670? It has the same processing power as a 660Ti. Both are 1344 CUDA core parts. The GTX 660 is GK106 and has 960 CUDA cores and that has performance just under (sometimes over depending on game and settings) GTX 580 which is very similar to 7870 performance. 660Ti is generally faster than GTX 580 and 7870 usually falling right below 7950.

Well, well, what's interesting is that the GTX 660 Ti is actually performing worse than the HD 7870 here:

(1920x1080)

and 2560x1440:

I used to have GTX 660 Ti in the same class as HD 7950. Then after I dropped it into the same class as HD 7870 (with 660 Ti at the top, and 7870 at the bottom of that class), the prices started to come closer to each other - since 660 Ti was $310-330, and 7870 was $230.
Now, 660 Ti is as low as $270, while 7870 is $220.

Much better.

Hahaha,
now try your focus group tricks on that!
Gotcha! :awe:

 

[amenx]

Well, well, what's interesting is that the GTX 660 Ti is actually performing worse than the HD 7870 here:

I used to have GTX 660 Ti in the same class as HD 7950. Then after I dropped it into the same class as HD 7870 (with 660 Ti at the top, and 7870 at the bottom of that class), the prices started to come closer to each other - since 660 Ti was $310-330, and 7870 was $230.
Now, 660 Ti is as low as $270, while 7870 is $220.

Much better.

Hahaha,
now try your focus group tricks on that!
Gotcha! :awe:

But what makes your source any more authoritative than the others? Virtually all other reviews out there contradict it.

 

[Keysplayr]

But what makes your source any more authoritative than the others? Virtually all other reviews out there contradict it.

He cherry picked to "prove me wrong" I guess. You can see the focus group pitchfork mentality kick in. But yeah, 7870 is generally slower than the GTX580 and so is the GTX660. The 660Ti is faster than the GTX580 and so it the GTX660Ti and 7950. But I'm sure Bofox might be able to find an instance or two where this isn't true if he looks long enough.

P.S. WTF Bofox. Have another beer.

 

[BoFox]

No taking up on the challenge then? Perhaps a couple beers would've made it fun for you to find at least 2-3 sources to counter-act this! It's your job after all! Ha ha (evil laughter)!

(Don't worry amenx, it's not authoritative enough to make me rate GTX 660 Ti less than HD 7870, ha! I kid like a fool!)

 

[Hdgamer]

If this were the case, with Titan being 384 memory bus, would it use all of the 6 gigs of Vram? I have yet to see my 660ti's go over 1450 vram on my 2560X1600 display. Playing games like the Witcher 2 and Skyrim just does not eat up the Vram that people say it does, but then again I don't mod games or care to.

 

[Jaydip]

Depends on the nature of the app.So far I'm not aware of any game which can utilize it but pro apps sure.