discussion The GTX 970's Memory Explained & Tested (Comment Thread)

[SKYMTL]

Here it is. 20 edits later....

There has been plenty of controversy about NVIDIA's GTX 970 and the way the core addresses its associated memory. In this article we explain the limitations and test whether or not they have a negative effect on performance.

Read more here: http://www.hardwarecanucks.com/foru...s/68595-gtx-970s-memory-explained-tested.html

 

[Dzzope]

Great write-up.. Frame times should put this to bed one way or another.

 

[SKYMTL]

Nothing will put this to bed once and for all. It's there to be picked away at.

 

[Sagath]

The questions I keep asking myself about this card, and this situation is this:

1) Would performance improve with a firmware update to make this a 3.5GB card by removing the 500mb partition?
2) If the answer is 'yes' to 1, should nVidia be lynched?
3) If the answer is 'no' to 1, do I give a crap?

#1 seems answered by the simple fact that the PCIe allocation is still slower then the on card 500mb (plus with optimizations on read/write operations, and striping) that it is fine with the extra ram.
#2 is...questionable. As this is the first time I can think of nVidia getting thrown under the bus in a long time I'm inclined to give them the benefit of the doubt. Now, should something like this happen again...Lynching should occur
#3 kinda got answered by #2 and #1. My card works, and works quite well. If I get into newer games that require more vram at 1440p and I start to see issues...well...I'll revisit the lynching solution

What I think would be fair (to 'put this to bed') is if nVidia provided reviewers with said firmware update...but as I said in #1, I'm not sold that would actually prove anything.

 

[draemn]

Nice article, a bit of an easy read (which is nice). I don't have a 970 but I think at the end of the day the in game benchmarks speak for themselves and show that it has very little impact on the end result: your gaming.

 

[jcmaz]

Pretty cool article!!

Btw, typo on the first page, 500MB not 500GB.

Within the 3.5GB section (red above), the strides are proceed sequentially while leaving the final 500GB of memory out of the equation. Thus, a game that calls for less than 3.5GB of memory will neatly avoid the buddy interface and final 500MB while still having access to 196GB/s of peak bandwidth. Meanwhile anything that requires more than 4GB of memory will cause draw calls to run through the system’s slow PCIe 19GB/s interface, completely hobbling performance due to the added latency. Calling for help from the PCIe bus for access to system memory occurs with every architecture when an onboard memory interface reaches the point of saturation.

 

[Footman]

Speaking as an individual who owns 2 x 970 in sli, I am a little annoyed at the current situation and am considering my options. Having said this I have not seen any performance issues or stuttering with my particular setup. 2560x1440 gaming at 120hz. All games have been flawless, including BF4 and Metro Last Light and these according to GPU-Z have been pulling more than 3.5gigs of Vram.
If there is a performance dip after 3.5gb vram it is not actually that significant and has not impacted my gaming or enjoyment.
Looking at the comparison to the GTX 980, the penalty in performance between memory usage under and over 3.5gb vram is not that great 4% approximately. I can live with that but I really do not appreciate being lied to. I actually own a video card with 3.5gb Vram and 512mb cache not a 4gb video card.

The delta in cost/performance to the GTX 980 is about where the gtx 970 should be now. It is still a great card and a good price. I'm keeping mine.

 

[Bond007]

Just read it all. Well written sky. This article really shows that AMD does extremely well in high memory use areas. Nice testing to get an idea of how this gtx 970 limitation affects real world gaming.

 

[LarkStarr]

While the facts are laid bare on the issue, there seems to be little effect on the end result. It's supposed to be weaker then the 980 and it seems to follow in line with that. Just because there's a (n insignificant) performance delta doesn't mean all that much. The FPS drop is more or less in line with the 980 anyways. There's also obviously a difference in clocks between the two, if they were tested at stock. What might be interesting to see is if the 970 can keep up with the performance delta of the 980 at the same clock rate. See if the unique architecture and the driver algorithm can keep up clock for clock. The performance level of the 970 still resides at -minimum-, 79% of the 980, with those games tested (BF4 >3.5Gigs , which is a drop from 85.4% <3.5gigs) - for a card that costs, what, 60% of a 980, you're still getting more value per dollar with the 970s

 

[Fragman]

This memory allocation issue is more relevant to people who bought GTX 970 SLI for 1440p and 4K gaming and are more likely to hit the > 3.5 GB to <= 4GB range due to the GPU power being available to play at those settings which utilize upto 4GB VRAM. fwiw this is from goldentiger who has GTX 970 SLI at 1440p . huge frametimes issues in Middle Earth with GTX 970 SLI at 1440p.

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