If you are a PC gamer you’ve likely heard that NVIDIA currently has a few unhappy customers as the GeForce GTX 970 4GB video card doesn’t have the advertised specifications. Since the GeForce GTX 970 video card was released it was discovered that the 4GB of GDDR5 memory doesn’t exactly work the same way as it does on a GTX 980. NVIDIA let everyone know that the GeForce GTX 970 features a partially disabled GM204 ‘Maxwell’ GPU that has 13 SMM units instead of the 16 SMMs on the GeForce GTX 980. With just 13 SMMs enabled it means that there are 1,664 functional CUDA cores rather than 2,048. That information was known from the start and has never been an issue. The issues at hand is that the memory setup isn’t what people thought it was.
For example the specifications of the NVIDIA GeForce GTX 970 4GB show the video card has 4GB of GDDR4 memory on a 256-bit wide bus running at 7.0Gbps and gets 224 GB/s of memory bandwidth. Some users noted that in certain situations that the GeForce GTX 970 reported 3.5GB of graphics memory and looked further into it. It turns out that NVIDIA is using a split memory configuration on this card due to three of the SM’s being disabled.
So, the NVIDIA GeForce GTX 970 4GB video card doesn’t really have one large 4GB memory block to write to, but rather a 3.5GB ‘high-priority segment’ and a 512MB ‘low-priority segment’. The GTX 970 has 4GB of memory that is functional on it, but it turns out that it might not have the theoretical bandwidth NVIDIA originally claimed due to how this configuration works on the GPU. So, from what we gather none of the GDDR5 memory runs at 224GB/sec like it was explained to us and that one section of the L2 cache has also been disabled. This means that the first 3.5GB sequent of memory operates at 196GB/s (7/8th) while the remaining 0.5GB operates at 1/8th that speed or at a rather paltry 28 GB/sec. Then with one of the eight L2 caches not being used it means that there are 56 functional ROPs instead of 64 and that there is just 1.75MB of L2 cache versus the 2MB that we were originally told the GTX 970 had. Some gamers have made some gifs to show how frustrated they are about the situation.
This is a rather startling discovery to me made this late after the card started being sold, but the good news is that all the rave reviews and happy users of this card were done like this. NVIDIA didn’t do a bait and switch or anything of the sort. NVIDIA has also released a statement showing that this memory configuration hurts performance by at most 3% when one uses over 3.5GB of frame buffer.
NVIDIA has sold over 1 million GeForce GTX 970 and GTX 980 video cards since their release and so far there doesn’t appear to be a real-world scenario that shows detrimental performance as a result of the GeForce GTX 970 video cards complex memory solution. That hasn’t stopped many gamers from being upset though as there is a petition that has been started for a refund that has nearly 5,000 signatures.
What is NVIDIA going to be doing about this situation? Other than the statement they already released we haven’t heard anything official from the tech giant. We did spot a forum post from [email protected] that stated NVIDIA is working on a driver update that will tune what’s allocated where in memory to further improve performance. Peter has since removed that post about the driver update and is pointing blame about #Ramgate to an error in the reviewers guide sent to press.
“Also, I understand that some of you are upset about the error in the reviewer guide. I apologize for that and can assure you that we have taken steps to ensure it doesn’t happen again.” – PeterS @ NVIDIA
We asked or PR contact for a statement on the post and we were simply told that they are always working on driver improvements for their product lineup. We have a feeling that NVIDIA is going to work on some optimizations, but it is pretty obvious that the final 512MB of memory will never be as fast as the 3.5GB segment due to how it is implemented. That might leave some gamers feeling like they got the shaft and that they are missing out from the high-end gaming card specifications that they bought.
In the meantime AMD is having some fun with this situation and has posted up an image on twitter that is rather humorous for those that don’t on a GeForce GTX 970.