With the highly anticipated Sept. 10 unveiling of the Apple Inc. (NASDAQ:AAPL) iPhone 5S just weeks away, a new round of rumors has suggested that the flagship version of the device may get a significant bump in specifications, improving the handset’s storage capacity and making it much faster than its predecessor.

Ming-Chi Kuo, an analyst at KGI Securities, recently said in a research note that the iPhone 5S would be made available with as much as 128GB of storage capacity, which will help “offer greater differentiation from iPhone 5.” Based on Kuo’s prediction, a MacRumors report said if Apple indeed releases the iPhone 5S with the new 128GB storage option, doubling the current maximum storage capacity of 64GB, it could result in the company discontinuing the 16GB storage option for the iPhone 5S, as it typically offers only three different storage options for its mobile devices.

Giving credence to what Kuo called for in his note, a German retailer apparently listed a 128GB iPhone in its sales system section recently. Although no stock-keeping unit, or SKU, code was revealed, the mysterious listing could possibly refer to a 128GB iPhone 5S model, the iDownload Blog reported.

Kuo also said the iPhone 5S would likely feature a new A7 system-on-chip design with 1GB of LPDDR3 RAM. Apple is expected to be able to optimize the faster LPDDR3 RAM spec for the A7 chip while keeping the amount of accessible memory to 1GB as the company itself controls both the operating system and hardware for the iPhone 5S.

“We reckon A7 will upgrade memory bandwidth spec to LPDDR3 from LPDDR2 adapted by A6, in an effort to improve system performance,” MacRumors quoted Kuo as saying. “Since Apple is in charge of both hardware and OS design, it is capable of minimalizing memory capacity at an optimized state. Therefore, A7’s RAM will likely be unchanged at 1GB.”

According to Kuo, the new A7 chip of the iPhone 5S is likely to be of Apple’s own design, based on the latest ARMv8 architecture, which is the successor of the ARMv7 setup of the A6 processor. By incorporating the new ARMv8, while tweaking both hardware and software, the company is expected to make the A7 processor 20 percent more efficient over the A6, AppleInsider reported.

Kuo’s prediction of a new A7 processor for the iPhone 5S makes sense, as the chip will be a logical step in the line of Apple processors, such as A4, A5 and A6. In addition, references to the A7 chip were recently found in a code within iOS 7.

Kuo also made an interesting remark that the iPhone 5S would be offered in a gold casing, in addition to the traditional black and white color options. The analyst’s prediction corresponds to an earlier reports, such as at MacRumors, which suggested that Apple could launch the iPhone 5S in multiple color options, including gold, bronze, or “champagne.”

Hot on the heels of Kuo’s claim, a set of images of the rear casing of a purported golden-colored iPhone 5S surfaced on the Internet Friday. The images, supposedly leaked to the French website MacBoutic, showed the same form factor as the iPhone 5.

In terms of the iPhone 5S camera, Kuo believes that the new smartphone will sport the same 8-megapixel sensor for its rear camera, but a dual LED flash and the increased aperture to F2.0 will help it perform better in lowlight conditions. Some previous reports said also that the next iPhone may even feature a 12- or 13-megapixel camera.

The iPhone 5S is also rumored to feature a new fingerprint sensor technology as an improvement to the handset’s security measures. The sensor is said to be embedded in the Home button, which is expected to be made out of sapphire and have a slightly convex shape.