Storage controller with the disk drive and the RAM in a hybrid architecture

#The present invention relates to an enhancement of a storage device for use with a computer system.

#Referring now to FIG. 1 a typical computer system 10 is shown. In such a computer system 10, because of the physical limitation of the magnetic media and optical media, the access speed of the disk drive 12 is between 0.004 second to 0.1 second. This time frame represents a much slower rate than that of a Central Processing Unit 11 (“CPU”) and the computer system's Random Access Memory 13 (“RAM”), which operates at access times of in several nanoseconds (i.e., {fraction (1/1,000,000,000)} of a second). The disk drive 12 is therefore the bottleneck of the computer system 10, as it operates much slower than the CPU 11 and RAM 13. Sophisticated operating systems and applications require more and more disk storage. It takes minutes to load an operating system and the applications.

#There are some technologies such as advanced disk caching which address some of these issues, but suffer from certain drawbacks. For example. and without limitation, only accessing continuous large blocks of disk data can take advantage of disk caching. Caching or caches consists of a very small amount of high speed SRAM. The content turn-over is very high (almost 100%). It is therefore not intended to store data permanently. Caching does not reduce initial seek time either since any additional data request will be forward to disk drive, whose speed is limited by mechanical rotation of the disk. Another known software technique such as RAMDisk, which uses software to emulate a disk drive with main RAM, improves the speed of accessing temporary data. However when a computer is powered down, the content of the RAMDisk is distorted. RAMDisk also has a very limited size as it is limited by the amount of main memory.

#FIG. 1 shows a block diagram of a typical prior art computer system.

#FIG. 2 shows a block diagram of the preferred embodiment of the present invention.

#FIG. 3 shows a block diagram of the first embodiment of the present invention in use with a computer.

#Referring now to FIGS. 2 and 3, a hybrid storage controller 106 is provided. Hybrid storage controller 106 is formed of a power source 105, a controller 101 and a plurality of separate RAM units 103 (collectively referred to as RAM unit or units 104). In this preferred embodiment of the invention, hybrid storage controller 106 and main memory or disk drive 102 are integrated into the same device 100.

#The hybrid storage controller 106 of the present invention comprises is connected to a disk drive 102. The controller 106 manages the data flowing between the computer system 50, the RAM 104 and the disk drive 102. The disk drive 102 is accessed only if the data block that a computer requests is not in the RAM units 104 or when the data block needs to be backed-up to disk drive 102 at a pre-determined period. The present invention significantly reduces the number of “seeks” on the disk drive 102 resulting in faster accessing time and longer disk drive life.

#In order to reduce the RAM 104 to disk drive 102 turn over (i.e., to avoid continuous searches or “seeks” for data from disk drive 102), a large amount of RAM 104 is needed within storage controller 106. In the preferred embodiment of the invention, at least two times of the main memory 12, 102 of the main computer system. The RAM 104 stores all the operating system files the current system needs and the virtual memory space that stores operating system and application temporary data. For example and without limitation, currently the average personal computer main memory 12, 102 has about 512 Megabytes of storage space, the controller 106 described in this invention must have at least 1 Gigabytes to take advantage of the hybrid architecture. It should be appreciated that the size or ratio of RAM unit 104 storage capacity to main memory 102 size may vary and that the storage capacity of RAM unit 104 should not be construed to be limited by the size of disc drive or memory 102. In another non-limiting embodiment of the invention, controller 106 continually monitors the RAM 104 to disk drive 10 “turn over” and may transmit a signal to the user (via the motherboard CPU and conventional display assembly) to alert the user of the computer system that additional RAM units 103 may be required to maintain the performance of the system..