GTX 550...first ever graphics card to ship with a mixed memory configuration

I guess those rumors were true as reviews are up now.

There are still six chips—two per memory controller. However, four of those are 128MB chips, while the remaining two have 256MB of capacity. In other words, two of the memory controllers shoulder 256MB each, and the third controller has 512MB all to itself. Nvidia says the GTX 550 Ti is its first ever graphics card to ship with such a mixed memory configuration. Supporting it required the implementation of custom logic in both the drivers and the GF116 GPU.

http://techreport.com/articles.x/20573

the article did go on to note the memory on the 512MB controller didn't seem to be full used, but didn't really elaborate on that. Seems nVidia found a somewhat slot inbetween the HD5770 and the HD6850 - a rather tight one, to be honest.

anandtech said that there are some issues with this memory setup. http://www.anandtech.com/show/4221/nvidias-gtx-550-ti-coming-up-short-at-150/2

Sounds like they are making it more complicated than it has to be which is just asking for problems.

[Edit] Just read the Anandtech article - good read and a lot of useful info. I would postulate that being the first time this has been implemented in a Video Card that there would be issues but I could forsee them using their low end cards to get this up and working in future cards.

My question- what is the point? Seems like they just want to be able to say its got a 1gb frame buffer, even if its not effectively used. If they were going to do extra memory, seems to me they should have either cut the bus and increased the memory speed to compensate, or just increase the amount of memory. Seems like this is gonna cause more problems than it will solve. I bet its really just marketing and all 3 memory controllers are identical, so that extra 256mb of memory is virtually unused and there just for show.

Interesting card and noteworthy improvement over the GTs 450. The pricing is shit though, it is currently priced to compete with the faster GTX 460 768 or GTX 460 se 1gb both of which cost the same and are faster.

All of those solutions above overclock like mad but the pricing of the GTX 550 Ti is definitely poor. Although I will note that one review I read earlier showed that they were able to overclock the core to over 1100 mhz which is insane.

I guess after seeing nvidia bobble the pricing of the GTX 560 Ti this shouldn't surprise me. I guess whenever we see Ti we can associate that with nvidia $20-$30 overpriced series. LOL

Graphics card makers have always been hesitant to implement a more fully-featured mixed memory controller. There's nothing physically limiting them from mixing memory sizes to make up for odd bus widths - they just have to account for more device variations. Desktop systems have been doing this for nearly a decade (dual-channel controllers with independent memory sizes on each channel).

The only problem in doing this is you want to tweak the memory controller so that it preferentially uses the matched memory set (128MB x 6), and only uses the top 256MB of the last two chips when all other memory has been exhausted. This is necessary because video cards are INCREDIBLY bandwidth-hungry, and you're basically doubling the amount of memory served by a fixed memory bus size. This means that the extra memory could be beneficial (more space), but using it could hurt performance slightly (half the relative bandwidth for that chunk of memory).

From my quick look around, this seems to hold-up in the benchmarks. Tech Power Up shows the gap between the 5770 and 550 closing as the resolution gets higher - these are the settings where the unmatched memory is likely used. It seems that matched memory is more efficient at 1080P and beyond, but that does not matter because these cards are designed for 1650. And at that resolution, the extra 256MB is more of an insurance policy than a necessity.

the gtx550 is not running settings in any benchmark that would exceed 768mb of vram. GTA 4, if it was tested, would be the only exception of playable settings on that level of card that could use more than 768mb.

cannondale06 said:

the gtx550 is not running settings in any benchmark that would exceed 768mb of vram. GTA 4, if it was tested, would be the only exception of playable settings on that level of card that could use more than 768mb.

Click to expand...

Sure it is. See here:

Metro 2033 1920x1200 4xAA

http://www.techpowerup.com/reviews/MSI/GeForce_GTX_550_Ti_Cyclone_II/16.html

The GTX 460 768MB card drops performance by half, and falls - it's out of memory. Performance of that card falls beneath the GTS 550, which still has enough ram to deliver "normal" (albeit slow) performance.

It's interesting to see how the gap between the 5770 and the GTS 550 closes at 1920x1200 4xAA, where the GTS 550 is depending more on it's extra ram with less bandwidth. The performance drop is not as sharp as cards that have completely run out of memory, but there is a drop:

1280x1024 no AA - %30 performance difference
1650x1050 4xAA - %20 performance difference
1920x1200 4xAA - %15 performance difference

Now, you'd never play a game at these settings with the GTS 550, but it is useful to look at the benchmark results. The extra memory is most definitely used at extremely high settings, but it comes at a slight performance cost. I like this approach versus just going with 768MB because you get a more gradual performance falloff, instead of just tumbling off a cliff.

yeah the memory is there but at playable settings it is of no use.