Updated: Benchmarks Show GTX 970 Has a Major Flaw

Published: January 23, 2015 5:05 PM /


gefoce gtx 970

Update: Nvidia has responded to complaints about the GTX 970.

"The GeForce GTX 970 is equipped with 4GB of dedicated graphics memory.  However the 970 has a different configuration of SMs than the 980, and fewer crossbar resources to the memory system. To optimally manage memory traffic in this configuration, we segment graphics memory into a 3.5GB section and a 0.5GB section.  The GPU has higher priority access to the 3.5GB section.  When a game needs less than 3.5GB of video memory per draw command then it will only access the first partition, and 3rd party applications that measure memory usage will report 3.5GB of memory in use on GTX 970, but may report more for GTX 980 if there is more memory used by other commands. When a game requires more than 3.5GB of memory then we use both segments.

We understand there have been some questions about how the GTX 970 will perform when it accesses the 0.5GB memory segment.  The best way to test that is to look at game performance.  Compare a GTX 980 to a 970 on a game that uses less than 3.5GB.  Then turn up the settings so the game needs more than 3.5GB and compare 980 and 970 performance again."

They then compare the framerate of 3 different games using the GTX 970 and GTX 980, using settings that require only 3.5 GB, and then rasing the settings to use more the 3.5 GB.
"On GTX 980, Shadows of Mordor drops about 24% on GTX 980 and 25% on GTX 970, a 1% difference.  On Battlefield 4, the drop is 47% on GTX 980 and 50% on GTX 970, a 3% difference.  On CoD: AW, the drop is 41% on GTX 980 and 44% on GTX 970, a 3% difference.  As you can see, there is very little change in the performance of the GTX 970 relative to GTX 980 on these games when it is using the 0.5GB segment."
While Nvidia suggests that the performance drop from going over the 3.5 GB limit is negligible, many users continue to complain about framerate issues when exceeding 3.5 GB. Other users however report no serious problems with GTX 970 even when going over 3.5 GB. The underlying cause seems to be rooted in the architecture of 970 and not something that can be fixed if users still find it to be a problem.

Original Story: The GTX 970 is one powerful graphics card. While its specs are slightly lower than its cousin, the GTX 980, it comes pretty close to matching it, and costs a couple hundred dollars less. For many consumers it offers the right balance of power and price, making it a worthwhile choice. Notably, it matches the 980's 4 GB VRAM. At least that's what the official specs say. However recent tests by users suggest it may not actually be able to make the full use of that 4 GB.

This problem was first noticed by users of the of the Guru3d.com forum. The poster noticed that when playing Far Cry 4 with the GTX 970 only 3.5 GB of VRAM are allocated, while playing the same games with the same settings the 980 allocates 4 GB of VRAM. This seemed to be a bit of a curiosity at first, rather than a major problem. If the game settings were raised than the 970 would allocate the full 4GB it required.

However, later in the thread users reported framerate issues if the allocated VRAM exceeds 3.5 GB. This was tested across multiple games including Watch Dogs and Hitman Absolution. This suggested there was a more serious problem than it seemed at first. While the card is apparently capable of allocating the full 4GB when it needs to, it has a much lower bandwidth when trying to access the last 500 MB. This is a problem unique to the GTX 970 and not shared by the 980, as shown in a side by side comparison. As you can see the in the image below, the GTX 970 is much slower at accessing the last 500 MB of VRAM. Click the image for full size.

GTX 970 980 benchmark comparison

This raises questions about what Nvidia should do about the problem, or what it is even capable of doing. Users on the forums suggest that this is a hardware problem and there is nothing that can actually be done to fix it, short of redesigning the chip and shipping out replacements to all affected customers. So far the only word on this issue from Nvidia is a moderator on the GeForce forum stating that Nvidia is aware of the problem, they are looking into it and will have an update as soon as possible.

Do you think Nvidia dropped the ball, and should have been aware of this problem before releasing the GTX 970 onto the market? How do you think they can make this right with customers? Leave your comment below.

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I’m a technology reporter located near the Innovation District of Kitchener-Waterloo, Ontario.