SINGLE-LEVEL CELL AND MULTI-LEVEL CELL HYBRID SOLID STATE DRIVE

• US 20130254458A1
• Filed: 03/26/2012
• Published: 09/26/2013
• Est. Priority Date: 03/26/2012
• Status: Active Grant

• Current Assignee: Dell International LLC (Dell Technologies Inc.)
• Original Assignee: Dell International LLC (Dell Technologies Inc.)
• Inventors: Pittelko, Michael H.
• Granted Patent: US 9,146,851 B2
• Time in Patent Office: Days
• US Class Current: 711/103
• CPC Class Codes: G06F 12/02 Addressing or allocation; Relocation program address sequencing G06F9/00; arrangements for selecting an address in a digital store G11C8/00
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/7202 Allocation control and policies
• CPC Class Codes: G06F 2212/7205 Cleaning, compaction, garbage collection, erase control

Abstract

A solid state drive (SSD) having a first memory portion comprising SLC flash memory and a second memory portion comprising MLC flash memory. The first memory portion may store read/write data, and the second memory portion may store read-only or read-mostly data. In some instances, the second memory portion may store historical data. The present disclosure also relates to a method of data progression in a hybrid solid state drive having both single-level cell (SLC) flash memory and multi-level cell (MLC) flash memory. The method may include monitoring write operations to the SLC memory, determining whether the frequency of write operations to a particular portion of the SLC memory is below a determined threshold, and moving the data stored in the particular portion of the SLC memory to the MLC memory.

Claims

1. A solid state drive (SSD) comprising a first memory portion comprising single-level cell (SLC) flash memory and a second memory portion comprising multi-level cell (MLC) flash memory.

2. The solid state drive of claim 1, wherein the first memory portion comprises less than 50% of the overall memory of the solid state drive.

3. The solid state drive of claim 2, wherein the first memory portion comprises between about 20% and 30% of the overall memory of the solid state drive.

4. The solid state drive of claim 1, wherein the first memory portion stores read/write data.

5. The solid state drive of claim 1, wherein the second memory portion stores read-mostly data.

6. The solid state drive of claim 4, wherein the second memory portion stores read-mostly data.

7. The solid state drive of claim 6, wherein the second memory portion stores historical data.

8. A data storage system comprising a hybrid solid state drive (SSD) comprising single-level cell (SLC) flash memory and multi-level cell (MLC) flash memory.

9. The data storage system of claim 8, further comprising hard disk drives.

10. The data storage system of claim 8, further configured to monitor write operations to the SLC memory of the hybrid SSD, determine whether the frequency of write operations to a particular portion of the SLC memory is below a determined threshold, and move the data stored in the particular portion of the SLC memory to the MLC memory of the hybrid SSD.

11. The data storage system of claim 10, further comprising another type of storage device, and configured to move data stored in the MLC memory of the hybrid SSD to the other type of storage device.

13. The data storage system of claim 8, further configured to store historical data in the MLC memory of the hybrid SSD.

12. The data storage system of Claim wherein the other type of storage device is a hard disk drive.

14. A method of data progression in a hybrid solid state drive having both single-level cell (SLC) flash memory and multi-level cell (MLC) flash memory, the method comprising:

monitoring write operations to the SLC memory;

determining whether the frequency of write operations to a particular portion of the SLC memory is below a determined threshold; and

moving the data stored in the particular portion of the SLC memory to the MLC memory.