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View Full Version : GTX980M in G751JY can only use 3,5 GB VRAM....



Tindreal
02-04-2015, 11:16 AM
The problem with GTX970 seems to affect our GTX980M too ...

See attachment. If a game uses more than 3,5 GB vRAM, than the speed of the card will drop down drastically ... maybe this is the reason why Watch Dogs stutter when I allow it to use more than 3GB vRAM ...

/sad panda...

NitroX
02-04-2015, 01:34 PM
Have you all gone mad with this thing about GTX970? Yes, NVidia should be ashamed for not respecting what they initially marketed to sell but the damn cards are still performing just the way they did as when they we're bought. All benchmarks and all results will remain the same even if now we know that the last 0.5GB of memory aren't on full speed.

And why in the name of God would the GTX980m be the same as the GTX970 ? The chips are totally different considering that these cards are made at a total different scale. And I did play games like Crysis 3 and Assassin's Cred Unity which went way over 3.5GB of memory used, and I did not encounter any issues with stutter or dropping framerates due to Memory Speed.

Btw, if the last 0.5GB of memory are working at a lower speed then you shouldn't have stutters if you pass over 3.5GB by a small margin, because the first 3.5GB would still work at maximum speed. The speed won't decrease for the whole memory. In fact, for me it doesn't even change for 1 second, and I'm always using an on screen monitor like MSI Afterburner so I can see if there are any changes in temperatures/frequencies.

My honest and humble opinion is to stop freaking out about this subject because it's not related to our hardware.

See here (below) why I don't quite trust this guys benchmarking tool and why I do not think that our GPU's performance is affected in any way by these new findings on GTX970.

1) Screenshot with the GPU at different clocks as it follows: Left side (No OC) - Center (5700Mhz Memory) - Right (5900Mhz Memory), all have different scores on the last 3 rows which pass 3.5GB:

46199

2) And these are the results from 3 different runs at the same clocks (Stock 5000Mhz Memory), also with different results on the last 3 rows which pass 3.5GB:
46200

And also, there are these guys from Guru3D that specifically said that they couldn't reproduce any stutter in games due to memory allocation. Indeed you could suffer some stuttering but not because you go over 3.5GB but because you will reach the 4GB limit and then stutters may appear due to memory limit. I'm usually gaming with 3.7-3.8GB and I didn't see any stutter due to memory speed.
http://www.guru3d.com/news-story/does-the-geforce-gtx-970-have-a-memory-allocation-bug.html

The conclusion is that our GTx980M can use it's full 4GB memory.

kmROGFAN
02-04-2015, 03:15 PM
I'm not an expert but as far as I know newer versions of Windows use the GPU for desktop composting, which means that a certain part of your VRAM is already allocated by Windows 8.1 to that end. Furthermore, I don't know if that's an issue but you seem to have Opera open and I know for a fact that Chrome allocates VRAM and uses the GPU for acceleration and modern Opera may be doing it as well. As a result when you try to allocate more memory and some of it is already reserved, system memory is used instead. I suspect this is what you are sometimes getting from the last chunks - the speed very close to the 16 GB/s which is pretty much the bandwith of 16xPCIe 3.0, the bus connecting the CPU to the GPU. It would also explain varying results - it is possible that as VRAM is freed by the OS you are back to getting higher results. That's why people use a special mode to run this test in which Windows VRAM usage is no longer a factor but I'm not familiar with it myself.
However, I might be wrong and the issue could very well apply but I still think that if you're still getting the performance you expect it doesn't really matter. If those stuttering issues persist, I would suggest giving feedback in Nvidia's forums. Also it would be useful to see the boundary at which they appear - if you are above 3.5GB but actually around 4GB stutters can occur because you are running out of VRAM :)

sk3tch
02-04-2015, 04:14 PM
This post is completely false. The GTX 980M is not affected with the same issue as the desktop GTX 970.

See this thread for proof: http://www.overclock.net/t/1535502/gtx-970s-can-only-use-3-5gb-of-4gb-vram-issue/1610. (I just tested it yesterday and had one of the guys involved with that benchmark tool verify that my results show the GTX 980M is not affected).

You need to make sure that you do the following things when you run Nai's Benchmark or you results will be skewed (plus, it is not a 100% reliable test):

- Close all applications (including web browsers)
- Close/disable Desktop Window Manager (dwm.exe) or kill processes

You can download the benchmark tool here: http://1pcent.com/?p=580.

d0r1n
02-04-2015, 10:06 PM
i played call of duty warface tonight and i got 79c cpu,72c gpu....memory al 4gb used and another 1gb from ram,so i got a total of 5gb
it was maxim details