The company then went on to promise a specific driver modification in order to alleviate the performance issues produced by the cutbacks suffered by the card. However, Nvidia later clarified that the promise had been a miscommunication and there would be no specific driver update for the GTX 970. Nvidia claimed that it would assist customers who wanted refunds in obtaining them. On February 26, 2015, Nvidia CEO Jen-Hsun Huang went on record in Nvidia's official blog to apologize for the incident. In February 2015 a class-action lawsuit alleging false advertising was filed against Nvidia and Gigabyte Technology in the U.S. District Court for Northern California. Nvidia revealed that it is able to disable individual units, each containing 256 KB of L2 cache and 8 ROPs, without disabling whole memory controllers. This comes at the cost of dividing the memory bus into high speed and low speed segments that cannot be accessed at the same time unless one segment is reading while the other segment is writing because the L2/ROP unit managing both of the GDDR5 controllers shares the read return channel and the write data bus between the two GDDR5 controllers and itself. This is used in the GeForce GTX 970, which therefore can be described as having 3.5 GB in its high speed segment on a 224-bit bus and 0.5 GB in a low speed segment on a 32-bit bus. On July 27, 2016, Nvidia agreed to a preliminary settlement of the U.S. class action lawsuit, offering a $30 refund on GTX 970 purchases. The agreed upon refund represents the portion of the cost of the storage and performance capabilities the consumers assumed they were obtaining when they purchased the card. Async compute support While the Maxwell series was marketed as fully DirectX 12 compliant, Oxide Games, developer of Ashes of the Singularity, uncovered that Maxwell-based cards do not perform well when async compute is utilized. It appears that while this core feature is in fact exposed by the driver, Nvidia partially implemented it through a driver-based shim, coming at a high performance cost. Unlike AMD's competing GCN-based graphics cards which include a full implementation of hardware-based asynchronous compute, Nvidia planned to rely on the driver to implement a software queue and a software distributor to forward asynchronous tasks to the hardware schedulers, capable of distributing the workload to the correct units. Asynchronous compute on Maxwell therefore requires