iPhone 6 front camera

Following unconfirmed reports that an unknown portion of iPhone 6 and iPhone 6 Plus units with 128 gigabytes of storage exhibit random boot looping and unexpected crashes, Apple has reportedly switched to using a different type of NAND flash technology.

The new iPhones use triple-level cell (TLC) NAND flash technology, but BusinessKorea reported Friday that the Cupertino firm will be switching to multi-level cell (MLC) NAND flash in the iPhone 6 and iPhone 6 Plus going forward.

Industry sources tell the publication that the iPhone 6 storage woes stem from a problem in the TLC NAND flash controller made by Israeli flash memory company Anobit, which Apple acquired in 2011 to help optimize flash storage performance of iOS devices.

While TLC NAND flash is more affordable and can store three times as much data as SLC ones, and 1.5 times as much as MLC technology, it’s also slower than SLC or MLC in terms of both reading and writing data.

Previous iPhones and some iPads used MLC NAND flash.

A growing thread on Apple’s Discussion forums highlights the issue, which appears to be limited to an unknown number of iPhone 6 and iPhone 6 Plus users who have large application libraries on their 128GB devices.

According to user reports, the affected devices exhibit fairly frequent crashes while some remain stuck in a boot loop following a restart.

Notions that the issue is related to a hardware problem associated with the increased storage available on the 128GB model is further ascertained by reports of poor read performance of the Samsung SSD 840 and 840 EVO using TLC NAND flash.

The affected users are advise to bring their devices to their Apple Store and few have reported success with new iPhone 6 Plus replacements. BusinessKorea claims that Apple’s upcoming iOS 8.1.1 update will fix the boot loop issues that have affected some iPhone 6 Plus users.

[BusinessKorea via MacRumors]